The pipeline is finally reasonably clean

clippy.toml

@@ -0,0 +1 @@
+type-complexity-threshold = 300

src/bin/orcx.rs

@@ -116,6 +116,7 @@ pub fn macro_debug(premacro: PreMacro, sym: Sym) {
         "Available commands:
         \t<blank>, n, next\t\ttake a step
         \tp, print\t\tprint the current state
+        \td, dump\t\tprint the rule table
         \tq, quit\t\texit
         \th, help\t\tprint this text"
       ),

src/error/conflicting_roles.rs

@@ -0,0 +1,31 @@
+use itertools::Itertools;
+
+use super::{ErrorPosition, ProjectError};
+use crate::utils::BoxedIter;
+use crate::{Location, VName};
+
+/// Error raised if the same name ends up assigned to more than one thing.
+/// A name in Orchid has exactly one meaning, either a value or a module.
+pub struct ConflictingRoles {
+  /// Name assigned to multiple things
+  pub name: VName,
+  /// Location of at least two occurrences
+  pub locations: Vec<Location>,
+}
+impl ProjectError for ConflictingRoles {
+  fn description(&self) -> &str {
+    "The same name is assigned multiple times to conflicting items"
+  }
+  fn message(&self) -> String {
+    format!(
+      "{} has multiple conflicting meanings",
+      self.name.iter().map(|t| t.as_str()).join("::")
+    )
+  }
+  fn positions(&self) -> BoxedIter<ErrorPosition> {
+    Box::new(
+      (self.locations.iter())
+        .map(|l| ErrorPosition { location: l.clone(), message: None }),
+    )
+  }
+}

src/error/import_all.rs

@@ -10,7 +10,7 @@ use crate::VName;
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct ImportAll {
   /// The file containing the offending import
-  pub offender_file: Rc<Vec<String>>,
+  pub offender_file: Rc<VName>,
   /// The module containing the offending import
   pub offender_mod: Rc<VName>,
 }

src/error/mod.rs

@@ -2,17 +2,18 @@
 mod import_all;
 mod no_targets;
 mod not_exported;
-mod not_found;
+// mod not_found;
+mod conflicting_roles;
 mod parse_error_with_tokens;
 mod project_error;
 mod too_many_supers;
 mod unexpected_directory;
 mod visibility_mismatch;
 
+pub use conflicting_roles::ConflictingRoles;
 pub use import_all::ImportAll;
 pub use no_targets::NoTargets;
 pub use not_exported::NotExported;
-pub use not_found::NotFound;
 pub use parse_error_with_tokens::ParseErrorWithTokens;
 pub use project_error::{ErrorPosition, ProjectError, ProjectResult};
 pub use too_many_supers::TooManySupers;

src/error/not_exported.rs

@@ -25,16 +25,14 @@ impl ProjectError for NotExported {
     Box::new(
       [
         ErrorPosition {
-          location: Location::File(Rc::new(Interner::extern_all(&self.file))),
+          location: Location::File(Rc::new(self.file.clone())),
           message: Some(format!(
             "{} isn't exported",
             Interner::extern_all(&self.subpath).join("::")
           )),
         },
         ErrorPosition {
-          location: Location::File(Rc::new(Interner::extern_all(
+          location: Location::File(Rc::new(self.referrer_file.clone())),
-            &self.referrer_file,
-          ))),
           message: Some(format!(
             "{} cannot see this symbol",
             Interner::extern_all(&self.referrer_subpath).join("::")

src/error/project_error.rs

@@ -1,5 +1,4 @@
-use std::fmt::Debug;
+use std::fmt::{Debug, Display};
-use std::fmt::Display;
 use std::rc::Rc;
 
 use crate::representations::location::Location;

src/error/too_many_supers.rs

@@ -1,5 +1,3 @@
-use std::rc::Rc;
-
 use super::ProjectError;
 use crate::representations::location::Location;
 use crate::{Interner, VName};
@@ -10,10 +8,8 @@ use crate::{Interner, VName};
 pub struct TooManySupers {
   /// The offending import path
   pub path: VName,
-  /// The file containing the offending import
+  /// The faulty import statement
-  pub offender_file: VName,
+  pub location: Location,
-  /// The module containing the offending import
-  pub offender_mod: VName,
 }
 impl ProjectError for TooManySupers {
   fn description(&self) -> &str {
@@ -22,13 +18,12 @@ impl ProjectError for TooManySupers {
   }
   fn message(&self) -> String {
     format!(
-      "path {} in {} contains too many `super` steps.",
+      "path {} contains too many `super` steps.",
       Interner::extern_all(&self.path).join("::"),
-      Interner::extern_all(&self.offender_mod).join("::")
     )
   }
 
   fn one_position(&self) -> Location {
-    Location::File(Rc::new(Interner::extern_all(&self.offender_file)))
+    self.location.clone()
   }
 }

src/error/unexpected_directory.rs

@@ -16,7 +16,7 @@ impl ProjectError for UnexpectedDirectory {
      to a directory"
   }
   fn one_position(&self) -> crate::Location {
-    Location::File(Rc::new(Interner::extern_all(&self.path)))
+    Location::File(Rc::new(self.path.clone()))
   }
 
   fn message(&self) -> String {

src/error/visibility_mismatch.rs

@@ -10,7 +10,7 @@ pub struct VisibilityMismatch {
   /// The namespace with ambiguous visibility
   pub namespace: VName,
   /// The file containing the namespace
-  pub file: Rc<Vec<String>>,
+  pub file: VName,
 }
 impl ProjectError for VisibilityMismatch {
   fn description(&self) -> &str {
@@ -23,6 +23,6 @@ impl ProjectError for VisibilityMismatch {
     )
   }
   fn one_position(&self) -> Location {
-    Location::File(self.file.clone())
+    Location::File(Rc::new(self.file.clone()))
   }
 }

src/facade/environment.rs

@@ -8,6 +8,7 @@ use super::PreMacro;
 use crate::error::ProjectResult;
 use crate::pipeline::file_loader;
 use crate::sourcefile::FileEntry;
+use crate::utils::never;
 use crate::{
   from_const_tree, parse_layer, vname_to_sym_tree, Interner, ProjectTree, Stok,
   VName,
@@ -39,7 +40,7 @@ impl<'a> Environment<'a> {
     let mut tree = from_const_tree(HashMap::new(), &[i.i("none")]);
     for sys in systems.iter() {
       let system_tree = from_const_tree(sys.constants.clone(), &sys.vname(i));
-      tree = ProjectTree(tree.0.overlay(system_tree.0));
+      tree = ProjectTree(never::unwrap_always(tree.0.overlay(system_tree.0)));
     }
     let mut prelude = vec![];
     for sys in systems.iter() {

src/facade/pre_macro.rs

@@ -42,12 +42,13 @@ impl<'a> PreMacro<'a> {
       repo,
       consts: (consts.into_iter())
         .map(|(name, expr)| {
+          // Figure out the location of the constant
           let location = (name.split_last())
             .and_then(|(_, path)| {
-              let origin = (tree.0.walk_ref(path, false))
+              let origin = (tree.0)
-                .expect("path sourced from symbol names");
+                .walk_ref(&[], path, false)
-              (origin.extra.file.as_ref())
+                .unwrap_or_else(|_| panic!("path sourced from symbol names"));
-                .map(|path| Interner::extern_all(&path[..]))
+              (origin.extra.file.as_ref()).cloned()
             })
             .map(|p| Location::File(Rc::new(p)))
             .unwrap_or(Location::Unknown);

src/facade/system.rs

@@ -16,7 +16,7 @@ pub struct System<'a> {
   /// External functions and other constant values defined in AST form
   pub constants: HashMap<Tok<String>, ConstTree>,
   /// Orchid libraries defined by this system
-  pub code: HashMap<Vec<Tok<String>>, Loaded>,
+  pub code: HashMap<VName, Loaded>,
   /// Prelude lines to be added to **subsequent** systems and usercode to
   /// expose the functionality of this system. The prelude is not added during
   /// the loading of this system
@@ -27,7 +27,7 @@ pub struct System<'a> {
 impl<'a> System<'a> {
   /// Intern the name of the system so that it can be used as an Orchid
   /// namespace
-  pub fn vname(&self, i: &Interner) -> Vec<Tok<String>> {
+  pub fn vname(&self, i: &Interner) -> VName {
     self.name.iter().map(|s| i.i(s)).collect::<Vec<_>>()
   }
 

src/foreign/cps_box.rs

@@ -1,13 +1,13 @@
 //! Automated wrappers to make working with CPS commands easier.
 
 use std::fmt::Debug;
-use std::iter;
 
 use trait_set::trait_set;
 
 use super::{Atomic, AtomicResult, AtomicReturn, ExternFn, XfnResult};
 use crate::interpreted::{Clause, ExprInst};
 use crate::interpreter::{Context, HandlerRes};
+use crate::utils::pushed::pushed_ref;
 use crate::{atomic_defaults, ConstTree};
 
 trait_set! {
@@ -39,10 +39,7 @@ impl<T: CPSPayload> ExternFn for CPSFn<T> {
   }
   fn apply(&self, arg: ExprInst, _ctx: Context) -> XfnResult {
     let payload = self.payload.clone();
-    let continuations = (self.continuations.iter())
+    let continuations = pushed_ref(&self.continuations, arg);
-      .cloned()
-      .chain(iter::once(arg))
-      .collect::<Vec<_>>();
     if self.argc == 1 {
       Ok(CPSBox { payload, continuations }.atom_cls())
     } else {

src/foreign_macros/atomic_impl.rs

@@ -40,7 +40,7 @@ use crate::Primitive;
 /// _definition of the `add` function in the STL_
 /// ```
 /// use orchidlang::{Literal};
-/// use orchidlang::interpreted::ExprInst;
+/// use orchidlang::interpreted::{ExprInst, Clause};
 /// use orchidlang::systems::cast_exprinst::with_lit;
 /// use orchidlang::{atomic_impl, atomic_redirect, externfn_impl};
 ///
@@ -63,10 +63,10 @@ use crate::Primitive;
 /// atomic_redirect!(InternalToString, expr_inst);
 /// atomic_impl!(InternalToString, |Self { expr_inst }: &Self, _|{
 ///   with_lit(expr_inst, |l| Ok(match l {
-///     Literal::Uint(i) => i.to_string(),
+///     Literal::Uint(i) => Literal::Str(i.to_string().into()),
-///     Literal::Num(n) => n.to_string(),
+///     Literal::Num(n) => Literal::Str(n.to_string().into()),
-///     Literal::Str(s) => s.clone(),
+///     s@Literal::Str(_) => s.clone(),
-///   })).map(|s| Literal::Str(s).into())
+///   })).map(Clause::from)
 /// });
 /// ```
 #[macro_export]

src/foreign_macros/define_fn.rs

@@ -42,15 +42,17 @@ use crate::write_fn_step;
 /// ```
 /// use orchidlang::interpreted::Clause;
 /// use orchidlang::systems::cast_exprinst::with_str;
-/// use orchidlang::{define_fn, Literal, Primitive};
+/// use orchidlang::{define_fn, Literal, OrcString, Primitive};
 ///
 /// define_fn! {expr=x in
 ///   /// Append a string to another
 ///   pub Concatenate {
-///     a: String as with_str(x, |s| Ok(s.clone())),
+///     a: OrcString as with_str(x, |s| Ok(s.clone())),
-///     b: String as with_str(x, |s| Ok(s.clone()))
+///     b: OrcString as with_str(x, |s| Ok(s.clone()))
 ///   } => {
-///     Ok(Clause::P(Primitive::Literal(Literal::Str(a.to_owned() + &b))))
+///     Ok(Clause::P(Primitive::Literal(Literal::Str(
+///       OrcString::from(a.get_string() + &b)
+///     ))))
 ///   }
 /// }
 /// ```
@@ -58,6 +60,7 @@ use crate::write_fn_step;
 /// A simpler format is also offered for unary functions:
 ///
 /// ```
+/// use orchidlang::interpreted::Clause;
 /// use orchidlang::systems::cast_exprinst::with_lit;
 /// use orchidlang::{define_fn, Literal};
 ///
@@ -65,10 +68,10 @@ use crate::write_fn_step;
 ///   /// Convert a literal to a string using Rust's conversions for floats,
 ///   /// chars and uints respectively
 ///   ToString = |x| with_lit(x, |l| Ok(match l {
-///     Literal::Uint(i) => i.to_string(),
+///     Literal::Uint(i) => Literal::Str(i.to_string().into()),
-///     Literal::Num(n) => n.to_string(),
+///     Literal::Num(n) => Literal::Str(n.to_string().into()),
-///     Literal::Str(s) => s.clone(),
+///     s@Literal::Str(_) => s.clone(),
-///   })).map(|s| Literal::Str(s).into())
+///   })).map(Clause::from)
 /// }
 /// ```
 #[macro_export]

src/foreign_macros/write_fn_step.rs

@@ -19,10 +19,9 @@ use crate::interpreted::ExprInst;
 /// also receive type annotations.
 ///
 /// ```
-/// // FIXME this is a very old example that wouldn't compile now
 /// use unicode_segmentation::UnicodeSegmentation;
 ///
-/// use orchidlang::{write_fn_step, Literal, Primitive};
+/// use orchidlang::{write_fn_step, Literal, Primitive, OrcString};
 /// use orchidlang::interpreted::Clause;
 /// use orchidlang::systems::cast_exprinst::{with_str, with_uint};
 /// use orchidlang::systems::RuntimeError;
@@ -32,20 +31,20 @@ use crate::interpreted::ExprInst;
 /// // Middle state
 /// write_fn_step!(
 ///   CharAt1 {}
-///   CharAt0 where s: String = x => with_str(x, |s| Ok(s.clone()));
+///   CharAt0 where s: OrcString = x => with_str(x, |s| Ok(s.clone()));
 /// );
 /// // Exit state
 /// write_fn_step!(
-///   CharAt0 { s: String }
+///   CharAt0 { s: OrcString }
 ///   i = x => with_uint(x, Ok);
 ///   {
 ///     if let Some(c) = s.graphemes(true).nth(*i as usize) {
-///       Ok(Literal::Str(c.to_string()).into())
+///       Ok(Literal::Str(OrcString::from(c.to_string())).into())
 ///     } else {
 ///       RuntimeError::fail(
 ///         "Character index out of bounds".to_string(),
 ///         "indexing string",
-///       )?
+///       )
 ///     }
 ///   }
 /// );

src/interner/token.rs

@@ -55,15 +55,15 @@ impl<T: Eq + Hash + Clone + 'static> Deref for Tok<T> {
   }
 }
 
-impl<T: Eq + Hash + Clone + 'static> Debug for Tok<T> {
+impl<T: Eq + Hash + Clone + 'static + Debug> Debug for Tok<T> {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-    write!(f, "Token({})", self.id())
+    write!(f, "Token({} -> {:?})", self.id(), self.data.as_ref())
   }
 }
 
 impl<T: Eq + Hash + Clone + Display + 'static> Display for Tok<T> {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-    write!(f, "{}", *self)
+    write!(f, "{}", **self)
   }
 }
 

src/interpreter/apply.rs

@@ -4,6 +4,7 @@ use super::Return;
 use crate::foreign::AtomicReturn;
 use crate::representations::interpreted::{Clause, ExprInst};
 use crate::representations::{PathSet, Primitive};
+use crate::utils::never::{unwrap_always, Always};
 use crate::utils::Side;
 
 /// Process the clause at the end of the provided path. Note that paths always
@@ -53,16 +54,12 @@ fn map_at<E>(
     .map(|p| p.0)
 }
 
-/// TODO replace when `!` gets stabilized
-#[derive(Debug)]
-enum Never {}
-
 /// Replace the [Clause::LambdaArg] placeholders at the ends of the [PathSet]
 /// with the value in the body. Note that a path may point to multiple
 /// placeholders.
 fn substitute(paths: &PathSet, value: Clause, body: ExprInst) -> ExprInst {
   let PathSet { steps, next } = paths;
-  map_at(steps, body, &mut |checkpoint| -> Result<Clause, Never> {
+  unwrap_always(map_at(steps, body, &mut |checkpoint| -> Always<Clause> {
     match (checkpoint, next) {
       (Clause::Lambda { .. }, _) => unreachable!("Handled by map_at"),
       (Clause::Apply { f, x }, Some((left, right))) => Ok(Clause::Apply {
@@ -77,8 +74,7 @@ fn substitute(paths: &PathSet, value: Clause, body: ExprInst) -> ExprInst {
         panic!("Substitution path leads into something other than Apply")
       },
     }
-  })
+  }))
-  .unwrap()
 }
 
 /// Apply a function-like expression to a parameter.

src/lib.rs

@@ -23,7 +23,6 @@ mod utils;
 pub use interner::{Interner, Tok};
 pub use pipeline::file_loader::{mk_dir_cache, mk_embed_cache};
 pub use pipeline::parse_layer;
-pub use representations::{NameLike, Sym, VName};
 /// Element of VName and a common occurrence in the API
 pub type Stok = Tok<String>;
 pub use representations::ast_to_interpreted::ast_to_interpreted;
@@ -32,6 +31,6 @@ pub use representations::project::{
 };
 pub use representations::{
   ast, from_const_tree, interpreted, sourcefile, tree, ConstTree, Literal,
-  Location, PathSet, Primitive,
+  Location, NameLike, OrcString, PathSet, Primitive, Sym, VName,
 };
 pub use utils::{thread_pool, Side, Substack};

src/parse/context.rs

@@ -1,16 +1,15 @@
 use std::rc::Rc;
 
 use crate::interner::Interner;
+use crate::{Tok, VName};
 
 /// Trait enclosing all context features
 ///
 /// Hiding type parameters in associated types allows for simpler
 /// parser definitions
 pub trait Context: Clone {
-  type Op: AsRef<str>;
+  fn ops(&self) -> &[Tok<String>];
-
+  fn file(&self) -> Rc<VName>;
-  fn ops(&self) -> &[Self::Op];
-  fn file(&self) -> Rc<Vec<String>>;
   fn interner(&self) -> &Interner;
 }
 
@@ -18,38 +17,36 @@ pub trait Context: Clone {
 ///
 /// Hiding type parameters in associated types allows for simpler
 /// parser definitions
-pub struct ParsingContext<'a, Op> {
+pub struct ParsingContext<'a> {
-  pub ops: &'a [Op],
+  pub ops: &'a [Tok<String>],
   pub interner: &'a Interner,
-  pub file: Rc<Vec<String>>,
+  pub file: Rc<VName>,
 }
 
-impl<'a, Op> ParsingContext<'a, Op> {
+impl<'a> ParsingContext<'a> {
   pub fn new(
-    ops: &'a [Op],
+    ops: &'a [Tok<String>],
     interner: &'a Interner,
-    file: Rc<Vec<String>>,
+    file: Rc<VName>,
   ) -> Self {
     Self { ops, interner, file }
   }
 }
 
-impl<'a, Op> Clone for ParsingContext<'a, Op> {
+impl<'a> Clone for ParsingContext<'a> {
   fn clone(&self) -> Self {
     Self { ops: self.ops, interner: self.interner, file: self.file.clone() }
   }
 }
 
-impl<Op: AsRef<str>> Context for ParsingContext<'_, Op> {
+impl Context for ParsingContext<'_> {
-  type Op = Op;
-
   fn interner(&self) -> &Interner {
     self.interner
   }
-  fn file(&self) -> Rc<Vec<String>> {
+  fn file(&self) -> Rc<VName> {
     self.file.clone()
   }
-  fn ops(&self) -> &[Self::Op] {
+  fn ops(&self) -> &[Tok<String>] {
     self.ops
   }
 }

src/parse/errors.rs

@@ -6,7 +6,7 @@ use itertools::Itertools;
 use super::{Entry, Lexeme};
 use crate::error::{ErrorPosition, ProjectError};
 use crate::utils::BoxedIter;
-use crate::{Location, Tok};
+use crate::{Location, Tok, VName};
 
 #[derive(Debug)]
 pub struct LineNeedsPrefix {
@@ -234,7 +234,7 @@ impl ProjectError for GlobExport {
 pub struct LexError {
   pub errors: Vec<Simple<char>>,
   pub source: Rc<String>,
-  pub file: Rc<Vec<String>>,
+  pub file: VName,
 }
 impl ProjectError for LexError {
   fn description(&self) -> &str {
@@ -244,7 +244,7 @@ impl ProjectError for LexError {
     let file = self.file.clone();
     Box::new(self.errors.iter().map(move |s| ErrorPosition {
       location: Location::Range {
-        file: file.clone(),
+        file: Rc::new(file.clone()),
         range: s.span(),
         source: self.source.clone(),
       },

src/parse/facade.rs

@@ -14,7 +14,12 @@ pub fn parse2(data: &str, ctx: impl Context) -> ProjectResult<Vec<FileEntry>> {
   let source = Rc::new(data.to_string());
   let lexie = lexer(ctx.clone(), source.clone());
   let tokens = (lexie.parse(data)).map_err(|errors| {
-    LexError { errors, file: ctx.file(), source: source.clone() }.rc()
+    LexError {
+      errors,
+      file: ctx.file().as_ref().clone(),
+      source: source.clone(),
+    }
+    .rc()
   })?;
   if tokens.is_empty() {
     Ok(Vec::new())

src/parse/lexer.rs

@@ -14,8 +14,9 @@ use super::number::print_nat16;
 use super::{comment, name, number, placeholder, string};
 use crate::ast::{PHClass, Placeholder};
 use crate::interner::Tok;
+use crate::parse::operators::operators_parser;
 use crate::representations::Literal;
-use crate::Location;
+use crate::{Interner, Location, VName};
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Entry {
@@ -47,7 +48,7 @@ impl Entry {
     self.location.range().expect("An Entry can only have a known location")
   }
 
-  pub fn file(&self) -> Rc<Vec<String>> {
+  pub fn file(&self) -> Rc<VName> {
     self.location.file().expect("An Entry can only have a range location")
   }
 }
@@ -106,14 +107,15 @@ pub enum Lexeme {
   /// Backslash
   BS,
   At,
-  Dot,
+  // Dot,
   Type, // type operator
-  Comment(String),
+  Comment(Rc<String>),
   Export,
   Import,
   Module,
   Macro,
   Const,
+  Operators(Rc<VName>),
   Placeh(Placeholder),
 }
 
@@ -135,7 +137,6 @@ impl Display for Lexeme {
       Self::BR => writeln!(f),
       Self::BS => write!(f, "\\"),
       Self::At => write!(f, "@"),
-      Self::Dot => write!(f, "."),
       Self::Type => write!(f, ":"),
       Self::Comment(text) => write!(f, "--[{}]--", text),
       Self::Export => write!(f, "export"),
@@ -143,6 +144,8 @@ impl Display for Lexeme {
       Self::Module => write!(f, "module"),
       Self::Const => write!(f, "const"),
       Self::Macro => write!(f, "macro"),
+      Self::Operators(ops) =>
+        write!(f, "operators[{}]", Interner::extern_all(ops).join(" ")),
       Self::Placeh(Placeholder { name, class }) => match *class {
         PHClass::Scalar => write!(f, "${}", **name),
         PHClass::Vec { nonzero, prio } => {
@@ -185,16 +188,19 @@ fn paren_parser(lp: char, rp: char) -> impl SimpleParser<char, Lexeme> {
   just(lp).to(Lexeme::LP(lp)).or(just(rp).to(Lexeme::RP(lp)))
 }
 
-pub fn literal_parser<'a>(ctx: impl Context + 'a) -> impl SimpleParser<char, Literal> + 'a {
+pub fn literal_parser<'a>(
+  ctx: impl Context + 'a,
+) -> impl SimpleParser<char, Literal> + 'a {
   choice((
     // all ints are valid floats so it takes precedence
     number::int_parser().map(Literal::Uint),
     number::float_parser().map(Literal::Num),
-    string::str_parser().map(move |s| Literal::Str(ctx.interner().i(&s).into())),
+    string::str_parser()
+      .map(move |s| Literal::Str(ctx.interner().i(&s).into())),
   ))
 }
 
-pub static BASE_OPS: &[&str] = &[",", ".", "..", "..."];
+pub static BASE_OPS: &[&str] = &[",", ".", "..", "...", "*"];
 
 pub fn lexer<'a>(
   ctx: impl Context + 'a,
@@ -213,6 +219,11 @@ pub fn lexer<'a>(
     keyword("import").to(Lexeme::Import),
     keyword("macro").to(Lexeme::Macro),
     keyword("const").to(Lexeme::Const),
+    operators_parser({
+      let ctx = ctx.clone();
+      move |s| ctx.interner().i(&s)
+    })
+    .map(|v| Lexeme::Operators(Rc::new(v))),
     paren_parser('(', ')'),
     paren_parser('[', ']'),
     paren_parser('{', '}'),
@@ -221,14 +232,14 @@ pub fn lexer<'a>(
       .ignore_then(number::float_parser())
       .then_ignore(just("=>"))
       .map(Lexeme::rule),
-    comment::comment_parser().map(Lexeme::Comment),
+    comment::comment_parser().map(|s| Lexeme::Comment(Rc::new(s))),
     placeholder::placeholder_parser(ctx.clone()).map(Lexeme::Placeh),
     just("::").to(Lexeme::NS),
     just('\\').to(Lexeme::BS),
     just('@').to(Lexeme::At),
     just(':').to(Lexeme::Type),
     just('\n').to(Lexeme::BR),
-    just('.').to(Lexeme::Dot),
+    // just('.').to(Lexeme::Dot),
     literal_parser(ctx.clone()).map(Lexeme::Literal),
     name::name_parser(&all_ops).map({
       let ctx = ctx.clone();

src/parse/mod.rs

@@ -7,6 +7,7 @@ mod lexer;
 mod multiname;
 mod name;
 mod number;
+mod operators;
 mod placeholder;
 mod sourcefile;
 mod stream;
@@ -15,5 +16,4 @@ mod string;
 pub use context::ParsingContext;
 pub use facade::parse2;
 pub use lexer::{lexer, Entry, Lexeme};
-pub use name::is_op;
+pub use number::{float_parser, int_parser, print_nat16};
-pub use number::{float_parser, int_parser};

src/parse/multiname.rs

@@ -8,19 +8,20 @@ use crate::error::{ProjectError, ProjectResult};
 use crate::sourcefile::Import;
 use crate::utils::iter::{box_chain, box_once};
 use crate::utils::BoxedIter;
-use crate::Tok;
+use crate::{Location, Tok};
 
 struct Subresult {
   glob: bool,
   deque: VecDeque<Tok<String>>,
+  location: Location,
 }
 impl Subresult {
-  fn new_glob() -> Self {
+  fn new_glob(location: Location) -> Self {
-    Self { glob: true, deque: VecDeque::new() }
+    Self { glob: true, deque: VecDeque::new(), location }
   }
 
-  fn new_named(name: Tok<String>) -> Self {
+  fn new_named(name: Tok<String>, location: Location) -> Self {
-    Self { glob: false, deque: VecDeque::from([name]) }
+    Self { location, glob: false, deque: VecDeque::from([name]) }
   }
 
   fn push_front(mut self, name: Tok<String>) -> Self {
@@ -29,10 +30,10 @@ impl Subresult {
   }
 
   fn finalize(self) -> Import {
-    let Self { mut deque, glob } = self;
+    let Self { mut deque, glob, location } = self;
     debug_assert!(glob || !deque.is_empty(), "The constructors forbid this");
     let name = if glob { None } else { deque.pop_back() };
-    Import { name, path: deque.into() }
+    Import { name, location, path: deque.into() }
   }
 }
 
@@ -75,7 +76,7 @@ fn parse_multiname_rec(
         let head;
         (head, cursor) = cursor.trim().pop()?;
         match &head.lexeme {
-          Lexeme::Name(n) => names.push(n),
+          Lexeme::Name(n) => names.push((n, head.location())),
           Lexeme::RP('[') => break,
           _ => {
             let err = Expected {
@@ -88,12 +89,14 @@ fn parse_multiname_rec(
         }
       }
       Ok((
-        Box::new(names.into_iter().map(|n| Subresult::new_named(n.clone()))),
+        Box::new(names.into_iter().map(|(name, location)| {
+          Subresult::new_named(name.clone(), location)
+        })),
         cursor,
       ))
     },
     Lexeme::Name(n) if *n == star =>
-      Ok((box_once(Subresult::new_glob()), cursor)),
+      Ok((box_once(Subresult::new_glob(head.location())), cursor)),
     Lexeme::Name(n) if ![comma, star].contains(n) => {
       let cursor = cursor.trim();
       if cursor.get(0).ok().map(|e| &e.lexeme) == Some(&Lexeme::NS) {
@@ -102,7 +105,7 @@ fn parse_multiname_rec(
         let out = Box::new(out.map(|sr| sr.push_front(n.clone())));
         Ok((out, cursor))
       } else {
-        Ok((box_once(Subresult::new_named(n.clone())), cursor))
+        Ok((box_once(Subresult::new_named(n.clone(), head.location())), cursor))
       }
     },
     _ => Err(

src/parse/name.rs

@@ -30,7 +30,7 @@ pub static NOT_NAME_CHAR: &[char] = &[
   '"', // parsed as primitive and therefore would never match
   '(', ')', '[', ']', '{', '}', // must be strictly balanced
   '.', // Argument-body separator in parametrics
-  ',', // used in imports
+  ',', // Import separator
 ];
 
 /// Matches anything that's allowed as an operator
@@ -39,18 +39,20 @@ pub static NOT_NAME_CHAR: &[char] = &[
 /// Could be an operator but then parametrics should take precedence,
 /// which might break stuff. investigate.
 ///
-/// TODO: `'` could work as an operator whenever it isn't closed.
-/// It's common im maths so it's worth a try
-///
 /// TODO: `.` could possibly be parsed as an operator in some contexts.
 /// This operator is very common in maths so it's worth a try.
 /// Investigate.
-pub fn modname_parser<'a>() -> impl SimpleParser<char, String> + 'a {
+pub fn anyop_parser<'a>() -> impl SimpleParser<char, String> + 'a {
-  filter(move |c| !NOT_NAME_CHAR.contains(c) && !c.is_whitespace())
+  filter(move |c| {
+    !NOT_NAME_CHAR.contains(c)
+      && !c.is_whitespace()
+      && !c.is_alphanumeric()
+      && c != &'_'
+  })
   .repeated()
   .at_least(1)
   .collect()
-    .labelled("modname")
+  .labelled("anyop")
 }
 
 /// Parse an operator or name. Failing both, parse everything up to
@@ -61,16 +63,7 @@ pub fn name_parser<'a>(
   choice((
     op_parser(ops), // First try to parse a known operator
     text::ident().labelled("plain text"), // Failing that, parse plain text
-    modname_parser(), // Finally parse everything until tne next forbidden char
+    anyop_parser(), // Finally parse everything until tne next forbidden char
   ))
   .labelled("name")
 }
-
-/// Decide if a string can be an operator. Operators can include digits
-/// and text, just not at the start.
-pub fn is_op(s: impl AsRef<str>) -> bool {
-  return match s.as_ref().chars().next() {
-    Some(x) => !x.is_alphanumeric(),
-    None => false,
-  };
-}

src/parse/operators.rs

@@ -0,0 +1,31 @@
+use chumsky::prelude::*;
+
+use super::decls::SimpleParser;
+
+pub fn operators_parser<T>(
+  f: impl Fn(String) -> T,
+) -> impl SimpleParser<char, Vec<T>> {
+  filter(|c: &char| c != &']' && !c.is_whitespace())
+    .repeated()
+    .at_least(1)
+    .collect()
+    .map(f)
+    .separated_by(text::whitespace())
+    .allow_leading()
+    .allow_trailing()
+    .at_least(1)
+    .delimited_by(just("operators["), just(']'))
+}
+
+#[cfg(test)]
+mod test {
+  use chumsky::Parser;
+
+  use super::operators_parser;
+
+  #[test]
+  fn operators_scratchpad() {
+    let parsely = operators_parser(|s| s);
+    println!("{:?}", parsely.parse("operators[$ |> =>]"))
+  }
+}

src/parse/sourcefile.rs

@@ -15,9 +15,9 @@ use super::Entry;
 use crate::ast::{Clause, Constant, Expr, Rule};
 use crate::error::{ProjectError, ProjectResult};
 use crate::representations::location::Location;
-use crate::representations::sourcefile::{FileEntry, Member, ModuleBlock};
+use crate::representations::sourcefile::{FileEntry, MemberKind, ModuleBlock};
 use crate::representations::VName;
-use crate::sourcefile::Import;
+use crate::sourcefile::{FileEntryKind, Import, Member};
 use crate::Primitive;
 
 pub fn split_lines(module: Stream<'_>) -> impl Iterator<Item = Stream<'_>> {
@@ -57,23 +57,31 @@ pub fn parse_module_body(
   split_lines(cursor)
     .map(Stream::trim)
     .filter(|l| !l.data.is_empty())
-    .map(|l| parse_line(l, ctx.clone()))
+    .map(|l| {
+      Ok(FileEntry {
+        locations: vec![l.location()],
+        kind: parse_line(l, ctx.clone())?,
+      })
+    })
     .collect()
 }
 
 pub fn parse_line(
   cursor: Stream<'_>,
   ctx: impl Context,
-) -> ProjectResult<FileEntry> {
+) -> ProjectResult<FileEntryKind> {
   match cursor.get(0)?.lexeme {
     Lexeme::BR | Lexeme::Comment(_) => parse_line(cursor.step()?, ctx),
     Lexeme::Export => parse_export_line(cursor.step()?, ctx),
-    Lexeme::Const | Lexeme::Macro | Lexeme::Module =>
+    Lexeme::Const | Lexeme::Macro | Lexeme::Module | Lexeme::Operators(_) =>
-      Ok(FileEntry::Internal(parse_member(cursor, ctx)?)),
+      Ok(FileEntryKind::Member(Member {
+        kind: parse_member(cursor, ctx)?,
+        exported: false,
+      })),
     Lexeme::Import => {
       let (imports, cont) = parse_multiname(cursor.step()?, ctx)?;
       cont.expect_empty()?;
-      Ok(FileEntry::Import(imports))
+      Ok(FileEntryKind::Import(imports))
     },
     _ => {
       let err = BadTokenInRegion {
@@ -88,23 +96,26 @@ pub fn parse_line(
 pub fn parse_export_line(
   cursor: Stream<'_>,
   ctx: impl Context,
-) -> ProjectResult<FileEntry> {
+) -> ProjectResult<FileEntryKind> {
   let cursor = cursor.trim();
   match cursor.get(0)?.lexeme {
     Lexeme::NS => {
       let (names, cont) = parse_multiname(cursor.step()?, ctx)?;
       cont.expect_empty()?;
       let names = (names.into_iter())
-        .map(|Import { name, path }| match (name, &path[..]) {
+        .map(|Import { name, path, location }| match (name, &path[..]) {
-          (Some(n), []) => Ok(n),
+          (Some(n), []) => Ok((n, location)),
-          (None, _) => Err(GlobExport { location: cursor.location() }.rc()),
+          (None, _) => Err(GlobExport { location }.rc()),
-          _ => Err(NamespacedExport { location: cursor.location() }.rc()),
+          _ => Err(NamespacedExport { location }.rc()),
         })
         .collect::<Result<Vec<_>, _>>()?;
-      Ok(FileEntry::Export(names))
+      Ok(FileEntryKind::Export(names))
     },
-    Lexeme::Const | Lexeme::Macro | Lexeme::Module =>
+    Lexeme::Const | Lexeme::Macro | Lexeme::Module | Lexeme::Operators(_) =>
-      Ok(FileEntry::Exported(parse_member(cursor, ctx)?)),
+      Ok(FileEntryKind::Member(Member {
+        kind: parse_member(cursor, ctx)?,
+        exported: true,
+      })),
     _ => {
       let err = BadTokenInRegion {
         entry: cursor.get(0)?.clone(),
@@ -118,20 +129,24 @@ pub fn parse_export_line(
 fn parse_member(
   cursor: Stream<'_>,
   ctx: impl Context,
-) -> ProjectResult<Member> {
+) -> ProjectResult<MemberKind> {
   let (typemark, cursor) = cursor.trim().pop()?;
-  match typemark.lexeme {
+  match &typemark.lexeme {
     Lexeme::Const => {
       let constant = parse_const(cursor, ctx)?;
-      Ok(Member::Constant(constant))
+      Ok(MemberKind::Constant(constant))
     },
     Lexeme::Macro => {
       let rule = parse_rule(cursor, ctx)?;
-      Ok(Member::Rule(rule))
+      Ok(MemberKind::Rule(rule))
     },
     Lexeme::Module => {
       let module = parse_module(cursor, ctx)?;
-      Ok(Member::Module(module))
+      Ok(MemberKind::Module(module))
+    },
+    Lexeme::Operators(ops) => {
+      cursor.trim().expect_empty()?;
+      Ok(MemberKind::Operators(ops[..].to_vec()))
     },
     _ => {
       let err =
@@ -234,8 +249,9 @@ fn parse_exprv(
         cursor = leftover;
       },
       Lexeme::BS => {
+        let dot = ctx.interner().i(".");
         let (arg, body) =
-          cursor.step()?.find("A '.'", |l| l == &Lexeme::Dot)?;
+          cursor.step()?.find("A '.'", |l| l == &Lexeme::Name(dot.clone()))?;
         let (arg, _) = parse_exprv(arg, None, ctx.clone())?;
         let (body, leftover) = parse_exprv(body, paren, ctx)?;
         output.push(Expr {

src/pipeline/dealias/alias_cache.rs

@@ -0,0 +1,59 @@
+use std::slice;
+
+use chumsky::primitive::Container;
+use hashbrown::HashMap;
+
+use crate::representations::project::{ProjectMod, ItemKind, ProjectEntry};
+use crate::tree::ModMember;
+use crate::utils::{pushed, unwrap_or};
+use crate::{ProjectTree, VName, Tok, NameLike};
+
+use super::walk_with_links::{walk_with_links, Target};
+
+pub struct AliasCache {
+  data: HashMap<Vec<Tok<String>>, Option<Vec<Tok<String>>>>,
+}
+impl AliasCache {
+  pub fn new() -> Self {
+    Self { data: HashMap::new() }
+  }
+
+  /// Finds the absolute nsname corresponding to the given name in the given
+  /// context, if it's imported. If the name is defined locally, returns None
+  /// to avoid allocating several vectors for every local variable.
+  pub fn resolv_name<'a>(
+    &'a mut self,
+    root: &ProjectMod<VName>,
+    location: &[Tok<String>],
+    name: Tok<String>
+  ) -> Option<&'a [Tok<String>]> {
+    let full_path = pushed(location, name);
+    if let Some(result) = self.data.get(&full_path) {
+      return result.as_deref();
+    }
+    let (ent, finalp) = walk_with_links(root, location.iter().cloned())
+      .expect("This path should be valid");
+    let m = unwrap_or!{ent => Target::Mod; panic!("Must be a module")};
+    let result = m.extra.imports_from.get(&name).map(|next| {
+      self.resolv_name(root, &next, name).unwrap_or(&next)
+    });
+    self.data.insert(full_path, result.map(|s| s.to_vec()));
+    return result;
+  }
+
+  /// Find the absolute target of a 
+  pub fn resolv_vec<'a>(
+    &'a mut self,
+    root: &ProjectMod<VName>,
+    modname: &[Tok<String>],
+    vname: &[Tok<String>],
+  ) -> Option<&'a [Tok<String>]> {
+    let (name, ns) = vname.split_last().expect("name cannot be empty");
+    if ns.is_empty() {
+      self.resolv_name(modname, name)
+    } else {
+      let origin = self.resolv_vec(modname, ns)?;
+      self.resolv_name(origin, name)
+    }
+  }
+}

src/pipeline/dealias/mod.rs

@@ -0,0 +1,5 @@
+// mod alias_cache;
+mod resolve_aliases;
+mod walk_with_links;
+
+pub use resolve_aliases::resolve_aliases;

src/pipeline/dealias/resolve_aliases.rs

@@ -0,0 +1,95 @@
+use std::iter;
+
+use itertools::Itertools;
+
+use super::walk_with_links::walk_with_links;
+use crate::ast::{Expr, Rule};
+use crate::representations::project::{
+  ItemKind, ProjectExt, ProjectItem, ProjectMod,
+};
+use crate::tree::{ModEntry, ModMember, Module};
+use crate::utils::pushed::pushed;
+use crate::{Interner, ProjectTree, Tok, VName};
+
+fn resolve_aliases_rec(
+  root: &ProjectMod<VName>,
+  module: &ProjectMod<VName>,
+  updated: &impl Fn(&[Tok<String>]) -> bool,
+  is_root: bool,
+) -> ProjectMod<VName> {
+  if !is_root && !updated(&module.extra.path) {
+    return module.clone();
+  }
+  let process_expr = |expr: &Expr<VName>| {
+    expr
+      .map_names(&|n| {
+        let full_name = (module.extra.path.iter()).chain(n.iter()).cloned();
+        match walk_with_links(root, full_name, false) {
+          Ok(rep) => Some(rep.abs_path),
+          // Ok(_) => None,
+          Err(e) => {
+            let leftovers = e.tail.collect::<Vec<_>>();
+            if !leftovers.is_empty() {
+              let full_name = (module.extra.path.iter())
+                .chain(n.iter())
+                .cloned()
+                .collect::<Vec<_>>();
+              let _ = walk_with_links(root, full_name.iter().cloned(), true);
+              panic!(
+                "Invalid path {} while resolving {} should have been noticed \
+                 earlier",
+                (e.abs_path.into_iter())
+                  .chain(iter::once(e.name))
+                  .chain(leftovers.into_iter())
+                  .join("::"),
+                Interner::extern_all(&full_name).join("::"),
+              );
+            }
+            Some(pushed(e.abs_path, e.name))
+          },
+        }
+      })
+      .unwrap_or_else(|| expr.clone())
+  };
+  Module {
+    extra: ProjectExt {
+      path: module.extra.path.clone(),
+      file: module.extra.file.clone(),
+      imports_from: module.extra.imports_from.clone(),
+      rules: (module.extra.rules.iter())
+        .map(|Rule { pattern, prio, template }| Rule {
+          pattern: pattern.iter().map(process_expr).collect(),
+          template: template.iter().map(process_expr).collect(),
+          prio: *prio,
+        })
+        .collect(),
+    },
+    entries: module
+      .entries
+      .iter()
+      .map(|(k, v)| {
+        (k.clone(), ModEntry {
+          exported: v.exported,
+          member: match &v.member {
+            ModMember::Sub(module) =>
+              ModMember::Sub(resolve_aliases_rec(root, module, updated, false)),
+            ModMember::Item(item) => ModMember::Item(ProjectItem {
+              is_op: item.is_op,
+              kind: match &item.kind {
+                ItemKind::Const(value) => ItemKind::Const(process_expr(value)),
+                other => other.clone(),
+              },
+            }),
+          },
+        })
+      })
+      .collect(),
+  }
+}
+
+pub fn resolve_aliases(
+  project: ProjectTree<VName>,
+  updated: &impl Fn(&[Tok<String>]) -> bool,
+) -> ProjectTree<VName> {
+  ProjectTree(resolve_aliases_rec(&project.0, &project.0, updated, true))
+}

src/pipeline/dealias/walk_with_links.rs

@@ -0,0 +1,124 @@
+#[allow(unused)] // for doc
+use crate::representations::project::ProjectEntry;
+use crate::representations::project::{ItemKind, ProjectItem, ProjectMod};
+use crate::tree::ModMember;
+use crate::utils::{unwrap_or, BoxedIter};
+use crate::{Interner, NameLike, Tok, VName};
+
+/// The destination of a linked walk. [ProjectEntry] cannot be used for this
+/// purpose because it might be the project root.
+pub enum Target<'a, N: NameLike> {
+  Mod(&'a ProjectMod<N>),
+  Leaf(&'a ProjectItem<N>),
+}
+
+pub struct WalkReport<'a, N: NameLike> {
+  pub target: Target<'a, N>,
+  pub abs_path: VName,
+  pub aliased: bool,
+}
+
+pub struct LinkWalkError<'a> {
+  /// The last known valid path
+  pub abs_path: VName,
+  /// The name that wasn't found
+  pub name: Tok<String>,
+  /// Leftover steps
+  pub tail: BoxedIter<'a, Tok<String>>,
+  /// Whether an alias was ever encountered
+  pub aliased: bool,
+}
+
+fn walk_with_links_rec<'a, 'b, N: NameLike>(
+  mut abs_path: VName,
+  root: &'a ProjectMod<N>,
+  cur: &'a ProjectMod<N>,
+  prev_tgt: Target<'a, N>,
+  aliased: bool,
+  mut path: impl Iterator<Item = Tok<String>> + 'b,
+  l: bool,
+) -> Result<WalkReport<'a, N>, LinkWalkError<'b>> {
+  let name = unwrap_or! {path.next();
+    // ends on this module
+    return Ok(WalkReport{ target: prev_tgt, abs_path, aliased })
+  };
+  if l {
+    eprintln!(
+      "Resolving {} in {}",
+      name,
+      Interner::extern_all(&abs_path).join("::")
+    )
+  }
+  let entry = unwrap_or! {cur.entries.get(&name); {
+    // panic!("No entry {name} on {}", Interner::extern_all(&cur.extra.path).join("::"));
+    // leads into a missing branch
+    return Err(LinkWalkError{ abs_path, aliased, name, tail: Box::new(path) })
+  }};
+  match &entry.member {
+    ModMember::Sub(m) => {
+      // leads into submodule
+      abs_path.push(name);
+      walk_with_links_rec(abs_path, root, m, Target::Mod(m), aliased, path, l)
+    },
+    ModMember::Item(item) => match &item.kind {
+      ItemKind::Alias(alias) => {
+        // leads into alias (reset acc, cur, cur_entry)
+        if l {
+          eprintln!(
+            "{} points to {}",
+            Interner::extern_all(&abs_path).join("::"),
+            Interner::extern_all(alias).join("::")
+          )
+        }
+        abs_path.clone_from(alias);
+        abs_path.extend(path);
+        let path_acc = Vec::with_capacity(abs_path.len());
+        let new_path = abs_path.into_iter();
+        let tgt = Target::Mod(root);
+        walk_with_links_rec(path_acc, root, root, tgt, true, new_path, l)
+      },
+      ItemKind::Const(_) | ItemKind::None => {
+        abs_path.push(name);
+        match path.next() {
+          Some(name) => {
+            // leads into leaf
+            let tail = Box::new(path);
+            Err(LinkWalkError { abs_path, aliased, name, tail })
+          },
+          None => {
+            // ends on leaf
+            let target = Target::Leaf(item);
+            Ok(WalkReport { target, abs_path, aliased })
+          },
+        }
+      },
+    },
+  }
+}
+
+/// Execute a walk down the tree, following aliases.
+/// If the path ends on an alias, that alias is also resolved.
+/// If the path leads out of the tree, the shortest failing path is returned
+pub fn walk_with_links<'a, N: NameLike>(
+  root: &ProjectMod<N>,
+  path: impl Iterator<Item = Tok<String>> + 'a,
+  l: bool,
+) -> Result<WalkReport<'_, N>, LinkWalkError<'a>> {
+  let path_acc = path.size_hint().1.map_or_else(Vec::new, Vec::with_capacity);
+  let mut result = walk_with_links_rec(
+    path_acc,
+    root,
+    root,
+    Target::Mod(root),
+    false,
+    path,
+    l,
+  );
+  // cut off excess preallocated space within normal vector growth policy
+  let abs_path = match &mut result {
+    Ok(rep) => &mut rep.abs_path,
+    Err(err) => &mut err.abs_path,
+  };
+  abs_path.shrink_to(abs_path.len().next_power_of_two());
+  result
+}

src/pipeline/file_loader.rs

@@ -11,14 +11,14 @@ use crate::error::{ProjectError, ProjectResult};
 use crate::facade::System;
 use crate::interner::Interner;
 use crate::utils::Cache;
-use crate::{Location, Stok, VName};
+use crate::{Location, Stok, Tok, VName};
 
 /// All the data available about a failed source load call
 #[derive(Debug)]
 pub struct FileLoadingError {
   file: io::Error,
   dir: io::Error,
-  path: Vec<String>,
+  path: VName,
 }
 impl ProjectError for FileLoadingError {
   fn description(&self) -> &str {
@@ -54,8 +54,8 @@ pub type IOResult = ProjectResult<Loaded>;
 
 /// Load a file from a path expressed in Rust strings, but relative to
 /// a root expressed as an OS Path.
-pub fn load_file(root: &Path, path: &[impl AsRef<str>]) -> IOResult {
+pub fn load_file(root: &Path, path: &[Tok<String>]) -> IOResult {
-  let full_path = path.iter().fold(root.to_owned(), |p, s| p.join(s.as_ref()));
+  let full_path = path.iter().fold(root.to_owned(), |p, t| p.join(t.as_str()));
   let file_path = full_path.with_extension("orc");
   let file_error = match fs::read_to_string(file_path) {
     Ok(string) => return Ok(Loaded::Code(Rc::new(string))),
@@ -68,7 +68,7 @@ pub fn load_file(root: &Path, path: &[impl AsRef<str>]) -> IOResult {
         FileLoadingError {
           file: file_error,
           dir: dir_error,
-          path: path.iter().map(|s| s.as_ref().to_string()).collect(),
+          path: path.to_vec(),
         }
         .rc(),
       ),
@@ -90,10 +90,7 @@ pub fn load_file(root: &Path, path: &[impl AsRef<str>]) -> IOResult {
 
 /// Generates a cached file loader for a directory
 pub fn mk_dir_cache(root: PathBuf) -> Cache<'static, VName, IOResult> {
-  Cache::new(move |vname: VName, _this| -> IOResult {
+  Cache::new(move |vname: VName, _this| load_file(&root, &vname))
-    let path = vname.iter().map(|t| t.as_str()).collect::<Vec<_>>();
-    load_file(&root, &path)
-  })
 }
 
 /// Load a file from the specified path from an embed table

src/pipeline/import_abs_path.rs

@@ -1,29 +1,22 @@
-use crate::error::{ProjectError, ProjectResult, TooManySupers};
+use crate::error::ProjectResult;
 use crate::interner::{Interner, Tok};
 use crate::representations::sourcefile::absolute_path;
 use crate::utils::Substack;
+use crate::{Location, VName};
 
 pub fn import_abs_path(
   src_path: &[Tok<String>],
   mod_stack: Substack<Tok<String>>,
   import_path: &[Tok<String>],
   i: &Interner,
-) -> ProjectResult<Vec<Tok<String>>> {
+  location: &Location,
+) -> ProjectResult<VName> {
   // path of module within file
   let mod_pathv = mod_stack.iter().rev_vec_clone();
   // path of module within compilation
-  let abs_pathv = (src_path.iter())
+  let abs_pathv =
-    .chain(mod_pathv.iter())
+    (src_path.iter()).chain(mod_pathv.iter()).cloned().collect::<Vec<_>>();
-    .cloned()
-    .collect::<Vec<_>>();
   // preload-target path relative to module
   // preload-target path within compilation
-  absolute_path(&abs_pathv, import_path, i).map_err(|_| {
+  absolute_path(&abs_pathv, import_path, i, location)
-    TooManySupers {
-      path: import_path.to_vec(),
-      offender_file: src_path.to_vec(),
-      offender_mod: mod_pathv,
-    }
-    .rc()
-  })
 }

src/pipeline/import_resolution/alias_map.rs

@@ -2,19 +2,19 @@ use std::hash::Hash;
 
 use hashbrown::{HashMap, HashSet};
 
-use crate::interner::Tok;
+use crate::{interner::Tok, VName};
 
 #[derive(Clone, Debug, Default)]
 pub struct AliasMap {
-  pub targets: HashMap<Vec<Tok<String>>, Vec<Tok<String>>>,
+  pub targets: HashMap<VName, VName>,
-  pub aliases: HashMap<Vec<Tok<String>>, HashSet<Vec<Tok<String>>>>,
+  pub aliases: HashMap<VName, HashSet<VName>>,
 }
 impl AliasMap {
   pub fn new() -> Self {
     Self::default()
   }
 
-  pub fn link(&mut self, alias: Vec<Tok<String>>, target: Vec<Tok<String>>) {
+  pub fn link(&mut self, alias: VName, target: VName) {
     let prev = self.targets.insert(alias.clone(), target.clone());
     debug_assert!(prev.is_none(), "Alias already has a target");
     multimap_entry(&mut self.aliases, &target).insert(alias.clone());
@@ -36,7 +36,7 @@ impl AliasMap {
     }
   }
 
-  pub fn resolve(&self, alias: &[Tok<String>]) -> Option<&Vec<Tok<String>>> {
+  pub fn resolve(&self, alias: &[Tok<String>]) -> Option<&VName> {
     self.targets.get(alias)
   }
 }

src/pipeline/import_resolution/apply_aliases.rs

@@ -1,18 +1,16 @@
-use hashbrown::HashMap;
-
 use super::alias_map::AliasMap;
 use super::decls::{InjectedAsFn, UpdatedFn};
 use crate::ast::{Expr, Rule};
 use crate::interner::Tok;
-use crate::representations::project::{ProjectExt, ProjectModule};
+use crate::representations::project::{ItemKind, ProjectMod};
-use crate::representations::tree::{ModEntry, ModMember};
+use crate::representations::tree::ModMember;
 use crate::representations::VName;
 use crate::utils::Substack;
 
 fn resolve_rec(
   namespace: &[Tok<String>],
   alias_map: &AliasMap,
-) -> Option<Vec<Tok<String>>> {
+) -> Option<VName> {
   if let Some(alias) = alias_map.resolve(namespace) {
     Some(alias.clone())
   } else if let Some((foot, body)) = namespace.split_last() {
@@ -28,7 +26,7 @@ fn resolve(
   namespace: &[Tok<String>],
   alias_map: &AliasMap,
   injected_as: &impl InjectedAsFn,
-) -> Option<Vec<Tok<String>>> {
+) -> Option<VName> {
   injected_as(namespace).or_else(|| {
     let next_v = resolve_rec(namespace, alias_map)?;
     Some(injected_as(&next_v).unwrap_or(next_v))
@@ -45,69 +43,44 @@ fn process_expr(
     .unwrap_or_else(|| expr.clone())
 }
 
-// TODO: replace is_injected with injected_as
 /// Replace all aliases with the name they're originally defined as
 fn apply_aliases_rec(
   path: Substack<Tok<String>>,
-  module: &ProjectModule<VName>,
+  module: &mut ProjectMod<VName>,
   alias_map: &AliasMap,
   injected_as: &impl InjectedAsFn,
   updated: &impl UpdatedFn,
-) -> ProjectModule<VName> {
+) {
-  let items = (module.items.iter())
+  for (name, entry) in module.entries.iter_mut() {
-    .map(|(name, ent)| {
+    match &mut entry.member {
-      let ModEntry { exported, member } = ent;
+      ModMember::Sub(sub) => {
-      let member = match member {
-        ModMember::Item(expr) =>
-          ModMember::Item(process_expr(expr, alias_map, injected_as)),
-        ModMember::Sub(module) => {
         let subpath = path.push(name.clone());
-          let new_mod = if !updated(&subpath.iter().rev_vec_clone()) {
+        apply_aliases_rec(subpath, sub, alias_map, injected_as, updated)
-            module.clone()
-          } else {
-            apply_aliases_rec(subpath, module, alias_map, injected_as, updated)
-          };
-          ModMember::Sub(new_mod)
       },
-      };
+      ModMember::Item(it) => match &mut it.kind {
-      (name.clone(), ModEntry { exported: *exported, member })
+        ItemKind::None => (),
-    })
+        ItemKind::Const(expr) =>
-    .collect::<HashMap<_, _>>();
+          *expr = process_expr(expr, alias_map, injected_as),
-  let rules = (module.extra.rules.iter())
+        ItemKind::Alias(name) =>
-    .map(|rule| {
+          if let Some(alt) = alias_map.resolve(&name) {
-      let Rule { pattern, prio, template } = rule;
+            *name = alt.clone()
-      Rule {
+          },
-        prio: *prio,
+      },
-        pattern: (pattern.iter())
+      _ => (),
-          .map(|expr| process_expr(expr, alias_map, injected_as))
+    }
-          .collect::<Vec<_>>(),
+  }
-        template: (template.iter())
+  for Rule { pattern, prio, template } in module.extra.rules.iter_mut() {
-          .map(|expr| process_expr(expr, alias_map, injected_as))
+    for expr in pattern.iter_mut().chain(template.iter_mut()) {
-          .collect::<Vec<_>>(),
+      *expr = process_expr(expr, alias_map, injected_as)
     }
-    })
-    .collect::<Vec<_>>();
-  ProjectModule {
-    items,
-    imports: module.imports.clone(),
-    extra: ProjectExt {
-      rules,
-      exports: (module.extra.exports.iter())
-        .map(|(k, v)| {
-          (k.clone(), resolve(v, alias_map, injected_as).unwrap_or(v.clone()))
-        })
-        .collect(),
-      file: module.extra.file.clone(),
-      imports_from: module.extra.imports_from.clone(),
-    },
   }
 }
 
 pub fn apply_aliases(
-  module: &ProjectModule<VName>,
+  module: &mut ProjectMod<VName>,
   alias_map: &AliasMap,
   injected_as: &impl InjectedAsFn,
   updated: &impl UpdatedFn,
-) -> ProjectModule<VName> {
+) {
   apply_aliases_rec(Substack::Bottom, module, alias_map, injected_as, updated)
 }

src/pipeline/import_resolution/collect_aliases.rs

@@ -1,134 +1,32 @@
 use super::alias_map::AliasMap;
 use super::decls::UpdatedFn;
-use crate::error::{NotExported, NotFound, ProjectError, ProjectResult};
+use crate::error::ProjectResult;
 use crate::interner::Tok;
-use crate::pipeline::project_tree::split_path;
+use crate::representations::project::{ProjectMod, ProjectTree};
-use crate::representations::project::{ProjectModule, ProjectTree};
+use crate::representations::tree::ModMember;
-use crate::representations::tree::{ModMember, WalkErrorKind};
 use crate::representations::VName;
-use crate::utils::{pushed, unwrap_or, Substack};
+use crate::utils::{pushed, unwrap_or};
-
-/// Assert that a module identified by a path can see a given symbol
-fn assert_visible(
-  source: &[Tok<String>], // must point to a file or submodule
-  target: &[Tok<String>], // may point to a symbol or module of any kind
-  project: &ProjectTree<VName>,
-) -> ProjectResult<()> {
-  let (tgt_item, tgt_path) = unwrap_or! {
-    target.split_last();
-    return Ok(())
-  };
-  let shared_len =
-    source.iter().zip(tgt_path.iter()).take_while(|(a, b)| a == b).count();
-  let vis_ignored_len = usize::min(tgt_path.len(), shared_len + 1);
-  let private_root = (project.0)
-    .walk_ref(&tgt_path[..vis_ignored_len], false)
-    .map_err(|e| match e.kind {
-      WalkErrorKind::Private =>
-        unreachable!("visibility is not being checked here"),
-      WalkErrorKind::Missing => NotFound::from_walk_error(
-        source,
-        &[],
-        &tgt_path[..vis_ignored_len],
-        &project.0,
-        e,
-      )
-      .rc(),
-    })?;
-  let direct_parent = private_root
-    .walk_ref(&tgt_path[vis_ignored_len..], true)
-    .map_err(|e| match e.kind {
-      WalkErrorKind::Missing => NotFound::from_walk_error(
-        source,
-        &tgt_path[..vis_ignored_len],
-        &tgt_path[vis_ignored_len..],
-        &project.0,
-        e,
-      )
-      .rc(),
-      WalkErrorKind::Private => {
-        let full_path = &tgt_path[..shared_len + e.pos];
-        // These errors are encountered during error reporting but they're more
-        // fundamental / higher prio than the error to be raised and would
-        // emerge nonetheless so they take over and the original error is
-        // swallowed
-        match split_path(full_path, project) {
-          Err(e) =>
-            NotFound::from_walk_error(source, &[], full_path, &project.0, e)
-              .rc(),
-          Ok((file, sub)) => {
-            let (ref_file, ref_sub) = split_path(source, project)
-              .expect("Source path assumed to be valid");
-            NotExported {
-              file: file.to_vec(),
-              subpath: sub.to_vec(),
-              referrer_file: ref_file.to_vec(),
-              referrer_subpath: ref_sub.to_vec(),
-            }
-            .rc()
-          },
-        }
-      },
-    })?;
-  let tgt_item_exported = direct_parent.extra.exports.contains_key(tgt_item);
-  let target_prefixes_source = shared_len == tgt_path.len();
-  if !tgt_item_exported && !target_prefixes_source {
-    let (file, sub) = split_path(target, project).map_err(|e| {
-      NotFound::from_walk_error(source, &[], target, &project.0, e).rc()
-    })?;
-    let (ref_file, ref_sub) = split_path(source, project)
-      .expect("The source path is assumed to be valid");
-    Err(
-      NotExported {
-        file: file.to_vec(),
-        subpath: sub.to_vec(),
-        referrer_file: ref_file.to_vec(),
-        referrer_subpath: ref_sub.to_vec(),
-      }
-      .rc(),
-    )
-  } else {
-    Ok(())
-  }
-}
 
 /// Populate target and alias maps from the module tree recursively
 fn collect_aliases_rec(
-  path: Substack<Tok<String>>,
+  path: Vec<Tok<String>>,
-  module: &ProjectModule<VName>,
+  module: &ProjectMod<VName>,
   project: &ProjectTree<VName>,
   alias_map: &mut AliasMap,
   updated: &impl UpdatedFn,
 ) -> ProjectResult<()> {
   // Assume injected module has been alias-resolved
-  let mod_path_v = path.iter().rev_vec_clone();
+  if !updated(&path) {
-  if !updated(&mod_path_v) {
     return Ok(());
   };
-  for (name, target_mod_name) in module.extra.imports_from.iter() {
+  for (name, target_sym_v) in module.extra.imports_from.iter() {
-    let target_sym_v = pushed(target_mod_name, name.clone());
+    let sym_path_v = pushed(&path, name.clone());
-    assert_visible(&mod_path_v, &target_sym_v, project)?;
+    alias_map.link(sym_path_v, target_sym_v.clone());
-    let sym_path_v = pushed(&mod_path_v, name.clone());
-    let target_mod = (project.0.walk_ref(target_mod_name, false))
-      .expect("checked above in assert_visible");
-    let target_sym = (target_mod.extra.exports.get(name))
-      .ok_or_else(|| {
-        let file_len =
-          target_mod.extra.file.as_ref().unwrap_or(target_mod_name).len();
-        NotFound {
-          source: Some(mod_path_v.clone()),
-          file: target_mod_name[..file_len].to_vec(),
-          subpath: target_sym_v[file_len..].to_vec(),
   }
-        .rc()
+  for (name, entry) in module.entries.iter() {
-      })?
-      .clone();
-    alias_map.link(sym_path_v, target_sym);
-  }
-  for (name, entry) in module.items.iter() {
     let submodule = unwrap_or!(&entry.member => ModMember::Sub; continue);
     collect_aliases_rec(
-      path.push(name.clone()),
+      pushed(&path, name.clone()),
       submodule,
       project,
       alias_map,
@@ -140,10 +38,10 @@ fn collect_aliases_rec(
 
 /// Populate target and alias maps from the module tree
 pub fn collect_aliases(
-  module: &ProjectModule<VName>,
+  module: &ProjectMod<VName>,
   project: &ProjectTree<VName>,
   alias_map: &mut AliasMap,
   updated: &impl UpdatedFn,
 ) -> ProjectResult<()> {
-  collect_aliases_rec(Substack::Bottom, module, project, alias_map, updated)
+  collect_aliases_rec(Vec::new(), module, project, alias_map, updated)
 }

src/pipeline/import_resolution/decls.rs

@@ -1,8 +1,8 @@
 use trait_set::trait_set;
 
-use crate::interner::Tok;
+use crate::{interner::Tok, VName};
 
 trait_set! {
-  pub trait InjectedAsFn = Fn(&[Tok<String>]) -> Option<Vec<Tok<String>>>;
+  pub trait InjectedAsFn = Fn(&[Tok<String>]) -> Option<VName>;
   pub trait UpdatedFn = Fn(&[Tok<String>]) -> bool;
 }

src/pipeline/import_resolution/mod.rs

@@ -3,5 +3,6 @@ mod apply_aliases;
 mod collect_aliases;
 mod decls;
 mod resolve_imports;
+mod alias_cache;
 
 pub use resolve_imports::resolve_imports;

src/pipeline/import_resolution/resolve_imports.rs

@@ -1,3 +1,4 @@
+use super::alias_cache::AliasCache;
 use super::alias_map::AliasMap;
 use super::apply_aliases::apply_aliases;
 use super::collect_aliases::collect_aliases;
@@ -9,12 +10,13 @@ use crate::representations::VName;
 /// Follow import chains to locate the original name of all tokens, then
 /// replace these aliases with the original names throughout the tree
 pub fn resolve_imports(
-  project: ProjectTree<VName>,
+  mut project: ProjectTree<VName>,
   injected_as: &impl InjectedAsFn,
   updated: &impl UpdatedFn,
 ) -> ProjectResult<ProjectTree<VName>> {
-  let mut map = AliasMap::new();
+  let mut cache = AliasCache::new(&project);
-  collect_aliases(&project.0, &project, &mut map, updated)?;
+  // let mut map = AliasMap::new();
-  let new_mod = apply_aliases(&project.0, &map, injected_as, updated);
+  // collect_aliases(&project.0, &project, &mut map, updated)?;
-  Ok(ProjectTree(new_mod))
+  // apply_aliases(&mut project.0, &map, injected_as, updated);
+  Ok(project)
 }

src/pipeline/mod.rs

@@ -1,7 +1,8 @@
 //! Loading Orchid modules from source
 pub mod file_loader;
 mod import_abs_path;
-mod import_resolution;
+// mod import_resolution;
+mod dealias;
 mod parse_layer;
 mod project_tree;
 mod source_loader;

src/pipeline/parse_layer.rs

@@ -1,11 +1,11 @@
-use std::rc::Rc;
+use super::dealias::resolve_aliases;
-
 use super::file_loader::IOResult;
-use super::{import_resolution, project_tree, source_loader};
+use super::{project_tree, source_loader};
 use crate::error::ProjectResult;
 use crate::interner::{Interner, Tok};
 use crate::representations::sourcefile::FileEntry;
 use crate::representations::VName;
+use crate::utils::never;
 use crate::ProjectTree;
 
 /// Using an IO callback, produce a project tree that includes the given
@@ -23,26 +23,17 @@ pub fn parse_layer<'a>(
   prelude: &[FileEntry],
   i: &Interner,
 ) -> ProjectResult<ProjectTree<VName>> {
-  // A path is injected if it is walkable in the injected tree
+  let (preparsed, source) =
-  let injected_as = |path: &[Tok<String>]| {
-    let (item, modpath) = path.split_last()?;
-    let module = environment.0.walk_ref(modpath, false).ok()?;
-    module.extra.exports.get(item).cloned()
-  };
-  let injected_names = |path: Tok<Vec<Tok<String>>>| {
-    let module = environment.0.walk_ref(&path, false).ok()?;
-    Some(Rc::new(module.extra.exports.keys().cloned().collect()))
-  };
-  let source =
     source_loader::load_source(targets, prelude, i, loader, &|path| {
-      environment.0.walk_ref(path, false).is_ok()
+      environment.0.walk_ref(&[], path, false).is_ok()
     })?;
-  let tree = project_tree::build_tree(source, i, prelude, &injected_names)?;
+  let tree =
-  let sum = ProjectTree(environment.0.clone().overlay(tree.0.clone()));
+    project_tree::rebuild_tree(&source, preparsed, environment, prelude, i)?;
+  let sum = ProjectTree(never::unwrap_always(
+    environment.0.clone().overlay(tree.0.clone()),
+  ));
   let resolvd =
-    import_resolution::resolve_imports(sum, &injected_as, &|path| {
+    resolve_aliases(sum, &|path| tree.0.walk1_ref(&[], path, false).is_ok());
-      tree.0.walk_ref(path, false).is_ok()
-    })?;
   // Addition among modules favours the left hand side.
   Ok(resolvd)
 }

src/pipeline/project_tree/add_prelude.rs

@@ -1,46 +0,0 @@
-use crate::interner::Tok;
-use crate::representations::sourcefile::{FileEntry, Member, ModuleBlock};
-
-fn member_rec(
-  // object
-  member: Member,
-  // context
-  path: &[Tok<String>],
-  prelude: &[FileEntry],
-) -> Member {
-  match member {
-    Member::Module(ModuleBlock { name, body }) => {
-      let new_body = entv_rec(body, path, prelude);
-      Member::Module(ModuleBlock { name, body: new_body })
-    },
-    any => any,
-  }
-}
-
-fn entv_rec(
-  // object
-  data: Vec<FileEntry>,
-  // context
-  mod_path: &[Tok<String>],
-  prelude: &[FileEntry],
-) -> Vec<FileEntry> {
-  prelude
-    .iter()
-    .cloned()
-    .chain(data.into_iter().map(|ent| match ent {
-      FileEntry::Exported(mem) =>
-        FileEntry::Exported(member_rec(mem, mod_path, prelude)),
-      FileEntry::Internal(mem) =>
-        FileEntry::Internal(member_rec(mem, mod_path, prelude)),
-      any => any,
-    }))
-    .collect()
-}
-
-pub fn add_prelude(
-  data: Vec<FileEntry>,
-  path: &[Tok<String>],
-  prelude: &[FileEntry],
-) -> Vec<FileEntry> {
-  entv_rec(data, path, prelude)
-}

src/pipeline/project_tree/build_tree.rs

@@ -1,246 +1,144 @@
 use hashbrown::HashMap;
-use itertools::Itertools;
+use itertools::{Either, Itertools};
 
-use super::collect_ops;
+use super::import_tree::ImpMod;
-use super::collect_ops::InjectedOperatorsFn;
+use crate::ast::{Constant, Rule};
-use super::parse_file::parse_file;
+use crate::error::{ConflictingRoles, ProjectError, ProjectResult};
-use crate::ast::{Clause, Constant, Expr};
+use crate::pipeline::source_loader::{PreItem, PreMod};
-use crate::error::{ProjectError, ProjectResult, TooManySupers};
+use crate::representations::project::{
-use crate::interner::{Interner, Tok};
+  ImpReport, ItemKind, ProjectEntry, ProjectExt, ProjectItem,
-use crate::pipeline::source_loader::{LoadedSource, LoadedSourceTable};
-use crate::representations::project::{ProjectExt, ProjectTree};
-use crate::representations::sourcefile::{absolute_path, FileEntry, Member};
-use crate::representations::tree::{ModEntry, ModMember, Module};
-use crate::representations::{NameLike, VName};
-use crate::tree::{WalkError, WalkErrorKind};
-use crate::utils::iter::{box_empty, box_once};
-use crate::utils::{pushed, unwrap_or, Substack};
-
-#[derive(Debug)]
-struct ParsedSource<'a> {
-  path: Vec<Tok<String>>,
-  loaded: &'a LoadedSource,
-  parsed: Vec<FileEntry>,
-}
-
-/// Split a path into file- and subpath in knowledge
-///
-/// # Errors
-///
-/// if the path is invalid
-#[allow(clippy::type_complexity)] // bit too sensitive here IMO
-pub fn split_path<'a>(
-  path: &'a [Tok<String>],
-  proj: &'a ProjectTree<impl NameLike>,
-) -> Result<(&'a [Tok<String>], &'a [Tok<String>]), WalkError> {
-  let (end, body) = unwrap_or!(path.split_last(); {
-    return Ok((&[], &[]))
-  });
-  let mut module = (proj.0.walk_ref(body, false))?;
-  let entry = (module.items.get(end))
-    .ok_or(WalkError { pos: path.len() - 1, kind: WalkErrorKind::Missing })?;
-  if let ModMember::Sub(m) = &entry.member {
-    module = m;
-  }
-  let file =
-    module.extra.file.as_ref().map(|s| &path[..s.len()]).unwrap_or(path);
-  let subpath = &path[file.len()..];
-  Ok((file, subpath))
-}
-
-/// Convert normalized, prefixed source into a module
-///
-/// # Panics
-///
-/// - if there are imports with too many "super" prefixes (this is normally
-///   detected in preparsing)
-/// - if the preparsed tree is missing a module that exists in the source
-fn source_to_module(
-  // level
-  path: Substack<Tok<String>>,
-  preparsed: &Module<impl Clone, impl Clone>,
-  // data
-  data: Vec<FileEntry>,
-  // context
-  i: &Interner,
-  filepath_len: usize,
-) -> ProjectResult<Module<Expr<VName>, ProjectExt<VName>>> {
-  let path_v = path.iter().rev_vec_clone();
-  let imports = (data.iter())
-    .filter_map(|ent| {
-      if let FileEntry::Import(impv) = ent { Some(impv.iter()) } else { None }
-    })
-    .flatten()
-    .cloned()
-    .collect::<Vec<_>>();
-  let imports_from = (imports.iter())
-    .map(|imp| -> ProjectResult<_> {
-      let mut imp_path_v = imp.path.clone();
-      imp_path_v
-        .push(imp.name.clone().expect("glob imports had just been resolved"));
-      let mut abs_path = absolute_path(&path_v, &imp_path_v, i)
-        .expect("should have failed in preparsing");
-      let name = abs_path.pop().ok_or_else(|| {
-        TooManySupers {
-          offender_file: path_v[..filepath_len].to_vec(),
-          offender_mod: path_v[filepath_len..].to_vec(),
-          path: imp_path_v,
-        }
-        .rc()
-      })?;
-      Ok((name, abs_path))
-    })
-    .collect::<Result<HashMap<_, _>, _>>()?;
-  let exports = (data.iter())
-    .flat_map(|ent| {
-      let mk_ent = |name: Tok<String>| (name.clone(), pushed(&path_v, name));
-      match ent {
-        FileEntry::Export(names) => Box::new(names.iter().cloned().map(mk_ent)),
-        FileEntry::Exported(mem) => match mem {
-          Member::Constant(constant) => box_once(mk_ent(constant.name.clone())),
-          Member::Module(ns) => box_once(mk_ent(ns.name.clone())),
-          Member::Rule(rule) => {
-            let mut names = Vec::new();
-            for e in rule.pattern.iter() {
-              e.search_all(&mut |e| {
-                if let Clause::Name(n) = &e.value {
-                  if let Some([name]) = n.strip_prefix(&path_v[..]) {
-                    names.push((name.clone(), n.clone()))
-                  }
-                }
-                None::<()>
-              });
-            }
-            Box::new(names.into_iter())
-          },
-        },
-        _ => box_empty(),
-      }
-    })
-    .collect::<HashMap<_, _>>();
-  let rules = (data.iter())
-    .filter_map(|ent| match ent {
-      FileEntry::Exported(Member::Rule(rule)) => Some(rule),
-      FileEntry::Internal(Member::Rule(rule)) => Some(rule),
-      _ => None,
-    })
-    .cloned()
-    .collect::<Vec<_>>();
-  let items = (data.into_iter())
-    .filter_map(|ent| {
-      let member_to_item = |exported, member| match member {
-        Member::Module(ns) => {
-          let new_prep = unwrap_or!(
-            &preparsed.items[&ns.name].member => ModMember::Sub;
-            panic!("Preparsed should include entries for all submodules")
-          );
-          let module = match source_to_module(
-            path.push(ns.name.clone()),
-            new_prep,
-            ns.body,
-            i,
-            filepath_len,
-          ) {
-            Err(e) => return Some(Err(e)),
-            Ok(t) => t,
 };
-          let member = ModMember::Sub(module);
+use crate::sourcefile::{
-          Some(Ok((ns.name.clone(), ModEntry { exported, member })))
+  FileEntry, FileEntryKind, Member, MemberKind, ModuleBlock,
-        },
-        Member::Constant(Constant { name, value }) => {
-          let member = ModMember::Item(value);
-          Some(Ok((name, ModEntry { exported, member })))
-        },
-        _ => None,
 };
-      match ent {
+use crate::tree::{ModEntry, ModMember, Module};
-        FileEntry::Exported(member) => member_to_item(true, member),
+use crate::utils::get_or_default;
-        FileEntry::Internal(member) => member_to_item(false, member),
+use crate::utils::pushed::pushed_ref;
-        _ => None,
+use crate::{Tok, VName};
-      }
-    })
-    .collect::<Result<HashMap<_, _>, _>>()?;
-  Ok(Module {
-    imports,
-    items,
-    extra: ProjectExt {
-      imports_from,
-      exports,
-      rules,
-      file: Some(path_v[..filepath_len].to_vec()),
-    },
-  })
-}
 
-fn files_to_module(
+pub struct TreeReport {
-  path: Substack<Tok<String>>,
+  pub entries: HashMap<Tok<String>, ProjectEntry<VName>>,
-  files: Vec<ParsedSource>,
+  pub rules: Vec<Rule<VName>>,
-  i: &Interner,
+  /// Maps imported symbols to the absolute paths of the modules they are
-) -> ProjectResult<Module<Expr<VName>, ProjectExt<VName>>> {
+  /// imported from
-  let lvl = path.len();
+  pub imports_from: HashMap<Tok<String>, ImpReport<VName>>,
-  debug_assert!(
-    files.iter().map(|f| f.path.len()).max().unwrap() >= lvl,
-    "path is longer than any of the considered file paths"
-  );
-  let path_v = path.iter().rev_vec_clone();
-  if files.len() == 1 && files[0].path.len() == lvl {
-    return source_to_module(
-      path.clone(),
-      &files[0].loaded.preparsed.0,
-      files[0].parsed.clone(),
-      i,
-      path.len(),
-    );
-  }
-  let items = (files.into_iter())
-    .group_by(|f| f.path[lvl].clone())
-    .into_iter()
-    .map(|(namespace, files)| -> ProjectResult<_> {
-      let subpath = path.push(namespace.clone());
-      let files_v = files.collect::<Vec<_>>();
-      let module = files_to_module(subpath, files_v, i)?;
-      let member = ModMember::Sub(module);
-      Ok((namespace, ModEntry { exported: true, member }))
-    })
-    .collect::<Result<HashMap<_, _>, _>>()?;
-  let exports: HashMap<_, _> = (items.keys())
-    .map(|name| (name.clone(), pushed(&path_v, name.clone())))
-    .collect();
-  Ok(Module {
-    items,
-    imports: vec![],
-    extra: ProjectExt {
-      exports,
-      imports_from: HashMap::new(),
-      rules: vec![],
-      file: None,
-    },
-  })
 }
 
 pub fn build_tree(
-  files: LoadedSourceTable,
+  path: &VName,
-  i: &Interner,
+  source: Vec<FileEntry>,
+  Module { entries, extra }: PreMod,
+  imports: ImpMod,
   prelude: &[FileEntry],
-  injected: &impl InjectedOperatorsFn,
+) -> ProjectResult<TreeReport> {
-) -> ProjectResult<ProjectTree<VName>> {
+  let source =
-  assert!(!files.is_empty(), "A tree requires at least one module");
+    source.into_iter().chain(prelude.iter().cloned()).collect::<Vec<_>>();
-  let ops_cache = collect_ops::mk_cache(&files, injected);
+  let (imports_from, mut submod_imports) = (imports.entries.into_iter())
-  let mut entries = files
+    .partition_map::<HashMap<_, _>, HashMap<_, _>, _, _, _>(
-    .iter()
+      |(n, ent)| match ent.member {
-    .map(|(path, loaded)| {
+        ModMember::Item(it) => Either::Left((n, it)),
-      Ok((path, loaded, parse_file(path, &files, &ops_cache, i, prelude)?))
+        ModMember::Sub(s) => Either::Right((n, s)),
-    })
+      },
-    .collect::<ProjectResult<Vec<_>>>()?;
+    );
-  // sort by similarity, then longest-first
+  let mut rule_fragments = Vec::new();
-  entries.sort_unstable_by(|a, b| a.0.cmp(b.0).reverse());
+  let mut submodules = HashMap::<_, Vec<_>>::new();
-  let files = entries
+  let mut consts = HashMap::new();
-    .into_iter()
+  for FileEntry { kind, locations: _ } in source {
-    .map(|(path, loaded, parsed)| ParsedSource {
+    match kind {
-      loaded,
+      FileEntryKind::Import(_) => (),
-      parsed,
+      FileEntryKind::Comment(_) => (),
-      path: path.clone(),
+      FileEntryKind::Export(_) => (),
-    })
+      FileEntryKind::Member(Member { kind, .. }) => match kind {
-    .collect::<Vec<_>>();
+        MemberKind::Module(ModuleBlock { body, name }) => {
-  Ok(ProjectTree(files_to_module(Substack::Bottom, files, i)?))
+          get_or_default(&mut submodules, &name).extend(body.into_iter());
+        },
+        MemberKind::Constant(Constant { name, value }) => {
+          consts.insert(name, value /* .prefix(path, &|_| false) */);
+        },
+        MemberKind::Operators(_) => (),
+        MemberKind::Rule(rule) => rule_fragments.push(rule),
+      },
+    }
+  }
+  let mod_details = extra.details().expect("Directories handled elsewhere");
+  let rules = (mod_details.patterns.iter())
+    .zip(rule_fragments.into_iter())
+    .map(|(p, Rule { prio, template: t, .. })| {
+      // let p = p.iter().map(|e| e.prefix(path, &|_| false)).collect();
+      // let t = t.into_iter().map(|e| e.prefix(path, &|_| false)).collect();
+      Rule { pattern: p.clone(), prio, template: t }
+    })
+    .collect();
+  let (pre_subs, pre_items) = (entries.into_iter())
+    .partition_map::<HashMap<_, _>, HashMap<_, _>, _, _, _>(
+      |(k, ModEntry { exported, member })| match member {
+        ModMember::Sub(s) => Either::Left((k, (exported, s))),
+        ModMember::Item(it) => Either::Right((k, (exported, it))),
+      },
+    );
+  let mut entries = (pre_subs.into_iter())
+    .map(|(k, (exported, pre_member))| {
+      let impmod = (submod_imports.remove(&k))
+        .expect("Imports and preparsed should line up");
+      (k, exported, pre_member, impmod)
+    })
+    .map(|(k, exported, pre, imp)| {
+      let source = submodules
+        .remove(&k)
+        .expect("Submodules should not disappear after reparsing");
+      (k, exported, pre, imp, source)
+    })
+    .map(|(k, exported, pre, imp, source)| {
+      let path = pushed_ref(path, k.clone());
+      let TreeReport { entries, imports_from, rules } =
+        build_tree(&path, source, pre, imp, prelude)?;
+      let extra = ProjectExt { path, file: None, imports_from, rules };
+      let member = ModMember::Sub(Module { entries, extra });
+      Ok((k, ModEntry { exported, member }))
+    })
+    .chain((pre_items.into_iter()).map(
+      |(k, (exported, PreItem { has_value, is_op, location }))| {
+        let item = match imports_from.get(&k) {
+          Some(_) if has_value => {
+            // Local value cannot be assigned to imported key
+            let const_loc =
+              consts.remove(&k).expect("has_value is true").location;
+            let err = ConflictingRoles {
+              locations: vec![location, const_loc],
+              name: pushed_ref(path, k),
+            };
+            return Err(err.rc());
+          },
+          None => {
+            let k = consts.remove(&k).map_or(ItemKind::None, ItemKind::Const);
+            ProjectItem { is_op, kind: k }
+          },
+          Some(report) => ProjectItem {
+            is_op: is_op | report.is_op,
+            kind: ItemKind::Alias(report.source.clone()),
+          },
+        };
+        Ok((k, ModEntry { exported, member: ModMember::Item(item) }))
+      },
+    ))
+    .collect::<Result<HashMap<_, _>, _>>()?;
+  for (k, from) in imports_from.iter() {
+    let (_, ent) = entries.raw_entry_mut().from_key(k).or_insert_with(|| {
+      (k.clone(), ModEntry {
+        exported: false,
+        member: ModMember::Item(ProjectItem {
+          kind: ItemKind::Alias(from.source.clone()),
+          is_op: from.is_op,
+        }),
+      })
+    });
+    debug_assert!(
+      matches!(
+        ent.member,
+        ModMember::Item(ProjectItem { kind: ItemKind::Alias(_), .. })
+      ),
+      "Should have emerged in the processing of pre_items"
+    )
+  }
+  Ok(TreeReport { entries, rules, imports_from })
 }

src/pipeline/project_tree/collect_ops/exported_ops.rs

@@ -1,79 +0,0 @@
-use std::rc::Rc;
-
-use hashbrown::HashSet;
-use trait_set::trait_set;
-
-use crate::error::{NotFound, ProjectError, ProjectResult};
-use crate::interner::Tok;
-use crate::pipeline::source_loader::LoadedSourceTable;
-use crate::representations::tree::WalkErrorKind;
-use crate::utils::{split_max_prefix, Cache};
-use crate::Sym;
-
-pub type OpsResult = ProjectResult<Rc<HashSet<Tok<String>>>>;
-pub type ExportedOpsCache<'a> = Cache<'a, Sym, OpsResult>;
-
-trait_set! {
-  pub trait InjectedOperatorsFn = Fn(Sym) -> Option<Rc<HashSet<Tok<String>>>>;
-}
-
-fn coprefix<T: Eq>(
-  l: impl Iterator<Item = T>,
-  r: impl Iterator<Item = T>,
-) -> usize {
-  l.zip(r).take_while(|(a, b)| a == b).count()
-}
-
-/// Collect all names exported by the module at the specified path
-pub fn collect_exported_ops(
-  path: Sym,
-  loaded: &LoadedSourceTable,
-  injected: &impl InjectedOperatorsFn,
-) -> OpsResult {
-  let injected =
-    injected(path.clone()).unwrap_or_else(|| Rc::new(HashSet::new()));
-  match split_max_prefix(&path, &|n| loaded.contains_key(n)) {
-    None => {
-      let ops = (loaded.keys())
-        .filter_map(|modname| {
-          if path.len() == coprefix(path.iter(), modname.iter()) {
-            Some(modname[path.len()].clone())
-          } else {
-            None
-          }
-        })
-        .chain(injected.iter().cloned())
-        .collect::<HashSet<_>>();
-      Ok(Rc::new(ops))
-    },
-    Some((fpath, subpath)) => {
-      let preparsed = &loaded[fpath].preparsed;
-      let module = preparsed.0.walk_ref(subpath, false).map_err(
-        |walk_err| match walk_err.kind {
-          WalkErrorKind::Private => {
-            unreachable!("visibility is not being checked here")
-          },
-          WalkErrorKind::Missing => NotFound {
-            source: None,
-            file: fpath.to_vec(),
-            subpath: subpath[..walk_err.pos].to_vec(),
-          }
-          .rc(),
-        },
-      )?;
-      let out = (module.items.iter())
-        .filter(|(_, v)| v.exported)
-        .map(|(k, _)| k.clone())
-        .chain(injected.iter().cloned())
-        .collect::<HashSet<_>>();
-      Ok(Rc::new(out))
-    },
-  }
-}
-
-pub fn mk_cache<'a>(
-  loaded: &'a LoadedSourceTable,
-  injected: &'a impl InjectedOperatorsFn,
-) -> ExportedOpsCache<'a> {
-  Cache::new(|path, _this| collect_exported_ops(path, loaded, injected))
-}

src/pipeline/project_tree/collect_ops/mod.rs

@@ -1,8 +0,0 @@
-mod exported_ops;
-mod ops_for;
-
-pub use exported_ops::{
-  collect_exported_ops, mk_cache, ExportedOpsCache, InjectedOperatorsFn,
-  OpsResult,
-};
-pub use ops_for::collect_ops_for;

src/pipeline/project_tree/collect_ops/ops_for.rs

@@ -1,53 +0,0 @@
-use std::rc::Rc;
-
-use hashbrown::HashSet;
-
-use super::exported_ops::{ExportedOpsCache, OpsResult};
-use crate::error::ProjectResult;
-use crate::interner::{Interner, Tok};
-use crate::parse::is_op;
-use crate::pipeline::import_abs_path::import_abs_path;
-use crate::pipeline::source_loader::LoadedSourceTable;
-use crate::representations::tree::{ModMember, Module};
-
-/// Collect all operators and names, exported or local, defined in this
-/// tree.
-fn tree_all_ops(
-  module: &Module<impl Clone, impl Clone>,
-  ops: &mut HashSet<Tok<String>>,
-) {
-  ops.extend(module.items.keys().cloned());
-  for ent in module.items.values() {
-    if let ModMember::Sub(m) = &ent.member {
-      tree_all_ops(m, ops);
-    }
-  }
-}
-
-/// Collect all names visible in this file
-///
-/// # Panics
-///
-/// if any import contains too many Super calls. This should be caught during
-/// preparsing
-pub fn collect_ops_for(
-  file: &[Tok<String>],
-  loaded: &LoadedSourceTable,
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> OpsResult {
-  let tree = &loaded[file].preparsed.0;
-  let mut ret = HashSet::new();
-  tree_all_ops(tree, &mut ret);
-  tree.visit_all_imports(&mut |modpath, _m, import| -> ProjectResult<()> {
-    if let Some(n) = &import.name {
-      ret.insert(n.clone());
-    } else {
-      let path = import_abs_path(file, modpath, &import.path, i)
-        .expect("This error should have been caught during loading");
-      ret.extend(ops_cache.find(&i.i(&path))?.iter().cloned());
-    }
-    Ok(())
-  })?;
-  Ok(Rc::new(ret.into_iter().filter(|t| is_op(&**t)).collect()))
-}

src/pipeline/project_tree/import_tree.rs

@@ -0,0 +1,169 @@
+use std::cmp::Ordering;
+use std::fmt::Display;
+use std::rc::Rc;
+
+use hashbrown::HashMap;
+use itertools::Itertools;
+
+use crate::error::{ProjectError, ProjectResult};
+use crate::pipeline::source_loader::{PreMod, Preparsed};
+use crate::representations::project::ImpReport;
+use crate::sourcefile::{absolute_path, Import};
+use crate::tree::{ErrKind, ModEntry, ModMember, Module, WalkError};
+use crate::utils::iter::{box_chain, box_once};
+use crate::utils::pushed::pushed_ref;
+use crate::utils::{unwrap_or, BoxedIter};
+use crate::{Interner, ProjectTree, Tok, VName};
+
+pub type ImpMod = Module<ImpReport<VName>, ()>;
+
+/// Assert that a module identified by a path can see a given symbol
+fn assert_visible<'a>(
+  source: &'a [Tok<String>], // must point to a file or submodule
+  target: &'a [Tok<String>],
+  root: &'a Module<impl Clone + Display, impl Clone + Display>,
+) -> Result<(), WalkError<'a>> {
+  if target.split_last().map_or(true, |(_, m)| source.starts_with(m)) {
+    // The global module (empty path) is always visible
+    return Ok(()); // Symbols in ancestor modules are always visible
+  }
+  // walk the first section where visibility is ignored
+  let shared_len =
+    source.iter().zip(target.iter()).take_while(|(a, b)| a == b).count();
+  let (shared_path, deep_path) = target.split_at(shared_len + 1);
+  let private_root = root.walk_ref(&[], shared_path, false)?;
+  // walk the second part where visibility matters
+  private_root.walk1_ref(shared_path, deep_path, true)?;
+  Ok(())
+}
+
+pub fn assert_visible_overlay<'a>(
+  source: &'a [Tok<String>], // must point to a file or submodule
+  target: &'a [Tok<String>],
+  first: &'a Module<impl Clone + Display, impl Clone + Display>,
+  fallback: &'a Module<impl Clone + Display, impl Clone + Display>,
+) -> Result<(), WalkError<'a>> {
+  assert_visible(source, target, first).or_else(|e1| {
+    if e1.kind == ErrKind::Missing {
+      match assert_visible(source, target, fallback) {
+        // if both are walk errors, report the longer of the two
+        Err(mut e2) if e2.kind == ErrKind::Missing =>
+          Err(match e1.depth().cmp(&e2.depth()) {
+            Ordering::Less => e2,
+            Ordering::Greater => e1,
+            Ordering::Equal => {
+              e2.options = box_chain!(e2.options, e1.options);
+              e2
+            },
+          }),
+        // otherwise return the parent's result
+        x => x,
+      }
+    } else {
+      Err(e1)
+    }
+  })
+}
+
+pub fn process_donor_module<'a, TItem: Clone>(
+  module: &'a Module<TItem, impl Clone>,
+  abs_path: Rc<VName>,
+  is_op: impl Fn(&TItem) -> bool + 'a,
+) -> impl Iterator<Item = (Tok<String>, VName, bool)> + 'a {
+  (module.entries.iter()).filter(|(_, ent)| ent.exported).map(
+    move |(n, ent)| {
+      let is_op = ent.item().map_or(false, &is_op);
+      (n.clone(), pushed_ref(abs_path.as_ref(), n.clone()), is_op)
+    },
+  )
+}
+
+pub fn import_tree(
+  modpath: VName,
+  pre: &PreMod,
+  root: &Preparsed,
+  prev_root: &ProjectTree<VName>,
+  i: &Interner,
+) -> ProjectResult<ImpMod> {
+  let imports = pre.extra.details().map_or(&[][..], |e| &e.imports[..]);
+  let entries = (imports.iter())
+    // imports become leaf sets
+    .map(|Import { name, path, location }| -> ProjectResult<BoxedIter<_>> {
+      let mut abs_path = absolute_path(&modpath, path, i, location)?;
+      Ok(if let Some(name) = name {
+        // named imports are validated and translated 1->1
+        abs_path.push(name.clone());
+        assert_visible_overlay(&modpath, &abs_path, &root.0, &prev_root.0)
+          .map_err(|e| -> Rc<dyn ProjectError> {
+            println!("Current root: {}", &root.0);
+            // println!("Old root: {:#?}", &prev_root.0);
+            panic!("{}", e.at(location))
+          })?;
+        let is_op = (root.0.walk1_ref(&[], &abs_path, false))
+          .map(|(ent, _)| ent.item().map_or(false, |i| i.is_op))
+          .or_else(|e| if e.kind == ErrKind::Missing {
+            (prev_root.0.walk1_ref(&[], &abs_path, false))
+              .map(|(ent, _)| ent.item().map_or(false, |i| i.is_op))
+          } else {Err(e)})
+          .map_err(|e| e.at(location))?;
+        box_once((name.clone(), abs_path, is_op))
+      } else {
+        let rc_path = Rc::new(abs_path);
+        // wildcard imports are validated
+        assert_visible_overlay(&modpath, &rc_path, &root.0, &prev_root.0)
+          .map_err(|e| e.at(location))?;
+        // and instantiated for all exports of the target 1->n
+        let new_imports = match (root.0).walk_ref(&[], &rc_path, false) {
+          Err(e) if e.kind == ErrKind::Missing => Err(e),
+          Err(e) => return Err(e.at(location)),
+          Ok(module)
+            => Ok(process_donor_module(module, rc_path.clone(), |i| i.is_op))
+        };
+        let old_m = match (prev_root.0).walk_ref(&[], &rc_path, false) {
+          Err(e) if e.kind != ErrKind::Missing => return Err(e.at(location)),
+          Err(e1) => match new_imports {
+            Ok(it) => return Ok(Box::new(it)),
+            Err(mut e2) => return Err(match e1.depth().cmp(&e2.depth()) {
+              Ordering::Less => e2.at(location),
+              Ordering::Greater => e1.at(location),
+              Ordering::Equal => {
+                e2.options = box_chain!(e2.options, e1.options);
+                e2.at(location)
+              },
+            }),
+          },
+          Ok(old_m) => old_m,
+        };
+        let it1 = process_donor_module(old_m, rc_path.clone(), |i| i.is_op);
+        match new_imports {
+          Err(_) => Box::new(it1),
+          Ok(it2) => box_chain!(it1, it2)
+        }
+      })
+    })
+    // leaf sets flattened to leaves
+    .flatten_ok()
+    // translated to entries
+    .map_ok(|(name, source, is_op)| {
+      (name, ModEntry {
+        exported: false, // this is irrelevant but needed
+        member: ModMember::Item(ImpReport { source, is_op }),
+      })
+    })
+    .chain(
+      (pre.entries.iter())
+        // recurse on submodules
+        .filter_map(|(k, v)| {
+          Some((k, v, unwrap_or!(&v.member => ModMember::Sub; return None)))
+        })
+        .map(|(k, v, pre)| {
+          let path = pushed_ref(&modpath, k.clone());
+          Ok((k.clone(), ModEntry {
+            exported: v.exported,
+            member: ModMember::Sub(import_tree(path, pre, root, prev_root, i)?),
+          }))
+        }),
+    )
+    .collect::<Result<HashMap<_, _>, _>>()?;
+  Ok(Module { extra: (), entries })
+}

src/pipeline/project_tree/mod.rs

@@ -1,24 +1,5 @@
-// FILE SEPARATION BOUNDARY
-//
-// Collect all operators accessible in each file, parse the files with
-// correct tokenization, resolve glob imports, convert expressions to
-// refer to tokens with (local) absolute path, and connect them into a
-// single tree.
-//
-// The module checks for imports from missing modules (including
-// submodules). All other errors must be checked later.
-//
-// Injection strategy:
-// Return all items of the given module in the injected tree for
-// `injected` The output of this stage is a tree, which can simply be
-// overlaid with the injected tree
-
-mod add_prelude;
 mod build_tree;
-mod collect_ops;
+mod import_tree;
-mod normalize_imports;
+mod rebuild_tree;
-mod parse_file;
-mod prefix;
 
-pub use build_tree::{build_tree, split_path};
+pub use rebuild_tree::rebuild_tree;
-pub use collect_ops::InjectedOperatorsFn;

src/pipeline/project_tree/normalize_imports.rs

@@ -1,94 +0,0 @@
-use super::collect_ops::ExportedOpsCache;
-use crate::interner::{Interner, Tok};
-use crate::pipeline::import_abs_path::import_abs_path;
-use crate::representations::sourcefile::{
-  FileEntry, Import, Member, ModuleBlock,
-};
-use crate::representations::tree::{ModMember, Module};
-use crate::utils::iter::box_once;
-use crate::utils::{unwrap_or, BoxedIter, Substack};
-
-fn member_rec(
-  // level
-  mod_stack: Substack<Tok<String>>,
-  preparsed: &Module<impl Clone, impl Clone>,
-  // object
-  member: Member,
-  // context
-  path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Member {
-  match member {
-    Member::Module(ModuleBlock { name, body }) => {
-      let subprep = unwrap_or!(
-        &preparsed.items[&name].member => ModMember::Sub;
-        unreachable!("This name must point to a namespace")
-      );
-      let new_stack = mod_stack.push(name.clone());
-      let new_body = entv_rec(new_stack, subprep, body, path, ops_cache, i);
-      Member::Module(ModuleBlock { name, body: new_body })
-    },
-    any => any,
-  }
-}
-
-/// Normalize imports in the FileEntry list recursively
-///
-/// # Panics
-///
-/// - if a path contains too many "super" prefixes
-/// - if the exported operators in a module cannot be determined
-fn entv_rec(
-  // level
-  mod_stack: Substack<Tok<String>>,
-  preparsed: &Module<impl Clone, impl Clone>,
-  // object
-  data: Vec<FileEntry>,
-  // context
-  mod_path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Vec<FileEntry> {
-  data
-    .into_iter()
-    .map(|ent| match ent {
-      FileEntry::Import(imps) => FileEntry::Import(
-        imps
-          .into_iter()
-          .flat_map(|import| {
-            if let Import { name: None, path } = import {
-              let p = import_abs_path(mod_path, mod_stack.clone(), &path, i)
-                .expect("Should have emerged in preparsing");
-              let names = (ops_cache.find(&i.i(&p)))
-                .expect("Should have emerged in second parsing");
-              let imports = (names.iter())
-                .map(|n| Import { name: Some(n.clone()), path: path.clone() })
-                .collect::<Vec<_>>();
-              Box::new(imports.into_iter()) as BoxedIter<Import>
-            } else {
-              box_once(import)
-            }
-          })
-          .collect(),
-      ),
-      FileEntry::Exported(mem) => FileEntry::Exported(member_rec(
-        mod_stack.clone(), preparsed, mem, mod_path, ops_cache, i,
-      )),
-      FileEntry::Internal(mem) => FileEntry::Internal(member_rec(
-        mod_stack.clone(), preparsed, mem, mod_path, ops_cache, i,
-      )),
-      any => any,
-    })
-    .collect()
-}
-
-pub fn normalize_imports(
-  preparsed: &Module<impl Clone, impl Clone>,
-  data: Vec<FileEntry>,
-  path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Vec<FileEntry> {
-  entv_rec(Substack::Bottom, preparsed, data, path, ops_cache, i)
-}

src/pipeline/project_tree/parse_file.rs

@@ -1,46 +0,0 @@
-use std::rc::Rc;
-
-use super::add_prelude::add_prelude;
-use super::collect_ops::{collect_ops_for, ExportedOpsCache};
-use super::normalize_imports::normalize_imports;
-use super::prefix::prefix;
-use crate::error::ProjectResult;
-use crate::interner::{Interner, Tok};
-use crate::parse;
-use crate::pipeline::source_loader::LoadedSourceTable;
-use crate::representations::sourcefile::{normalize_namespaces, FileEntry};
-
-/// Parses a file with the correct operator set
-///
-/// # Panics
-///
-/// - on syntax error
-/// - if namespaces are exported inconsistently
-///
-/// These are both checked in the preparsing stage
-pub fn parse_file(
-  path: &[Tok<String>],
-  loaded: &LoadedSourceTable,
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-  prelude: &[FileEntry],
-) -> ProjectResult<Vec<FileEntry>> {
-  let ld = &loaded[path];
-  // let ops_cache = collect_ops::mk_cache(loaded, i);
-  let ops = collect_ops_for(path, loaded, ops_cache, i)?;
-  let ops_vec = ops.iter().map(|t| (**t).clone()).collect::<Vec<_>>();
-  let ctx = parse::ParsingContext {
-    interner: i,
-    ops: &ops_vec,
-    file: Rc::new(Interner::extern_all(path)),
-  };
-  let entries = parse::parse2(ld.text.as_str(), ctx)
-    .expect("This error should have been caught during loading");
-  let with_prelude = add_prelude(entries, path, prelude);
-  let impnormalized =
-    normalize_imports(&ld.preparsed.0, with_prelude, path, ops_cache, i);
-  let nsnormalized = normalize_namespaces(Box::new(impnormalized.into_iter()))
-    .expect("This error should have been caught during preparsing");
-  let prefixed = prefix(nsnormalized, path, ops_cache, i);
-  Ok(prefixed)
-}

src/pipeline/project_tree/prefix.rs

@@ -1,73 +0,0 @@
-use super::collect_ops::ExportedOpsCache;
-use crate::ast::{Constant, Rule};
-use crate::interner::{Interner, Tok};
-use crate::representations::sourcefile::{FileEntry, Member, ModuleBlock};
-use crate::utils::Substack;
-
-fn member_rec(
-  // level
-  mod_stack: Substack<Tok<String>>,
-  // object
-  data: Member,
-  // context
-  path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Member {
-  let prefix = (path.iter())
-    .cloned()
-    .chain(mod_stack.iter().rev_vec_clone().into_iter())
-    .collect::<Vec<_>>();
-  match data {
-    Member::Module(ModuleBlock { name, body }) => {
-      let new_stack = mod_stack.push(name.clone());
-      let new_body = entv_rec(new_stack, body, path, ops_cache, i);
-      Member::Module(ModuleBlock { name, body: new_body })
-    },
-    Member::Constant(constant) => Member::Constant(Constant {
-      name: constant.name,
-      value: constant.value.prefix(&prefix, &|_| false),
-    }),
-    Member::Rule(rule) => Member::Rule(Rule {
-      prio: rule.prio,
-      pattern: (rule.pattern.into_iter())
-        .map(|e| e.prefix(&prefix, &|_| false))
-        .collect(),
-      template: (rule.template.into_iter())
-        .map(|e| e.prefix(&prefix, &|_| false))
-        .collect(),
-    }),
-  }
-}
-
-fn entv_rec(
-  // level
-  mod_stack: Substack<Tok<String>>,
-  // object
-  data: Vec<FileEntry>,
-  // context
-  path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Vec<FileEntry> {
-  (data.into_iter())
-    .map(|fe| {
-      let (mem, wrapper): (Member, fn(Member) -> FileEntry) = match fe {
-        FileEntry::Exported(mem) => (mem, FileEntry::Exported),
-        FileEntry::Internal(mem) => (mem, FileEntry::Internal),
-        // XXX should [FileEntry::Export] be prefixed?
-        any => return any,
-      };
-      wrapper(member_rec(mod_stack.clone(), mem, path, ops_cache, i))
-    })
-    .collect()
-}
-
-pub fn prefix(
-  data: Vec<FileEntry>,
-  path: &[Tok<String>],
-  ops_cache: &ExportedOpsCache,
-  i: &Interner,
-) -> Vec<FileEntry> {
-  entv_rec(Substack::Bottom, data, path, ops_cache, i)
-}

src/pipeline/project_tree/rebuild_tree.rs

@@ -0,0 +1,131 @@
+use std::rc::Rc;
+
+use hashbrown::HashMap;
+use itertools::Itertools;
+
+use super::build_tree::{build_tree, TreeReport};
+use super::import_tree::{import_tree, ImpMod};
+use crate::error::ProjectResult;
+use crate::pipeline::source_loader::{
+  LoadedSourceTable, PreExtra, PreItem, PreMod, Preparsed,
+};
+use crate::representations::project::{ImpReport, ProjectExt, ProjectMod};
+use crate::sourcefile::FileEntry;
+use crate::tree::{ModEntry, ModMember, Module};
+use crate::utils::never::{always, unwrap_always};
+use crate::utils::pushed::pushed_ref;
+use crate::utils::unwrap_or;
+use crate::{parse, Interner, ProjectTree, Tok, VName};
+
+pub fn rebuild_file(
+  path: Vec<Tok<String>>,
+  pre: PreMod,
+  imports: ImpMod,
+  source: &LoadedSourceTable,
+  prelude: &[FileEntry],
+  i: &Interner,
+) -> ProjectResult<ProjectMod<VName>> {
+  let file = match &pre.extra {
+    PreExtra::Dir => panic!("Dir should not hand this node off"),
+    PreExtra::Submod(_) => panic!("should not have received this"),
+    PreExtra::File(f) => f,
+  };
+  let mut ops = Vec::new();
+  unwrap_always(imports.search_all((), &mut |_, module, ()| {
+    ops.extend(
+      (module.entries.iter())
+        .filter(|(_, ent)| {
+          matches!(ent.member, ModMember::Item(ImpReport { is_op: true, .. }))
+        })
+        .map(|(name, _)| name.clone()),
+    );
+    always(())
+  }));
+  unwrap_always(pre.search_all((), &mut |_, module, ()| {
+    ops.extend(
+      (module.entries.iter())
+        .filter(|(_, ent)| {
+          matches!(ent.member, ModMember::Item(PreItem { is_op: true, .. }))
+        })
+        .map(|(name, _)| name.clone()),
+    );
+    always(())
+  }));
+  let ctx = parse::ParsingContext::new(&ops, i, Rc::new(path.clone()));
+  let src = source.get(&file.name).unwrap_or_else(|| {
+    panic!(
+      "{} should have been preparsed already. Preparsed files are {}",
+      Interner::extern_all(&file.name).join("/") + ".orc",
+      source
+        .keys()
+        .map(|f| Interner::extern_all(f).join("/") + ".orc")
+        .join(", ")
+    )
+  });
+  let entries = parse::parse2(&src.text, ctx)?;
+  let TreeReport { entries: items, rules, imports_from } =
+    build_tree(&path, entries, pre, imports, prelude)?;
+  Ok(Module {
+    entries: items,
+    extra: ProjectExt { file: Some(path.clone()), path, imports_from, rules },
+  })
+}
+
+pub fn rebuild_dir(
+  path: Vec<Tok<String>>,
+  pre: PreMod,
+  mut imports: ImpMod,
+  source: &LoadedSourceTable,
+  prelude: &[FileEntry],
+  i: &Interner,
+) -> ProjectResult<ProjectMod<VName>> {
+  match pre.extra {
+    PreExtra::Dir => (),
+    PreExtra::File(_) =>
+      return rebuild_file(path, pre, imports, source, prelude, i),
+    PreExtra::Submod(_) => panic!("Dirs contain dirs and files"),
+  }
+  let items = (pre.entries.into_iter())
+    .map(|(name, entry)| {
+      match imports.entries.remove(&name).map(|e| e.member) {
+        Some(ModMember::Sub(impmod)) => (name, entry, impmod),
+        _ => panic!("Imports must line up with modules"),
+      }
+    })
+    .map(|(name, ModEntry { member, exported }, impmod)| -> ProjectResult<_> {
+      let path = pushed_ref(&path, name.clone());
+      let pre = unwrap_or!(member => ModMember::Sub;
+        panic!("Dirs can only contain submodules")
+      );
+      Ok((name, ModEntry {
+        exported,
+        member: ModMember::Sub(rebuild_dir(
+          path, pre, impmod, source, prelude, i,
+        )?),
+      }))
+    })
+    .collect::<Result<HashMap<_, _>, _>>()?;
+  Ok(Module {
+    extra: ProjectExt {
+      path,
+      imports_from: HashMap::new(),
+      rules: Vec::new(),
+      file: None,
+    },
+    entries: items,
+  })
+}
+
+/// Rebuild the entire tree
+pub fn rebuild_tree(
+  source: &LoadedSourceTable,
+  preparsed: Preparsed,
+  prev_root: &ProjectTree<VName>,
+  prelude: &[FileEntry],
+  i: &Interner,
+) -> ProjectResult<ProjectTree<VName>> {
+  let imports =
+    import_tree(Vec::new(), &preparsed.0, &preparsed, prev_root, i)?;
+  rebuild_dir(Vec::new(), preparsed.0, imports, source, prelude, i)
+    .map(ProjectTree)
+}

src/pipeline/source_loader/load_source.rs

@@ -1,7 +1,8 @@
-use std::iter;
+use hashbrown::HashMap;
 
 use super::loaded_source::{LoadedSource, LoadedSourceTable};
 use super::preparse::preparse;
+use super::{PreExtra, Preparsed};
 use crate::error::{
   NoTargets, ProjectError, ProjectResult, UnexpectedDirectory,
 };
@@ -9,67 +10,79 @@ use crate::interner::{Interner, Tok};
 use crate::pipeline::file_loader::{IOResult, Loaded};
 use crate::pipeline::import_abs_path::import_abs_path;
 use crate::representations::sourcefile::FileEntry;
+use crate::tree::Module;
+use crate::utils::pushed::pushed_ref;
 use crate::utils::{split_max_prefix, unwrap_or};
+use crate::Location;
 
 /// Load the source at the given path or all within if it's a collection,
 /// and all sources imported from these.
 fn load_abs_path_rec(
   abs_path: &[Tok<String>],
-  table: &mut LoadedSourceTable,
+  mut all: Preparsed,
+  source: &mut LoadedSourceTable,
   prelude: &[FileEntry],
   i: &Interner,
   get_source: &impl Fn(&[Tok<String>]) -> IOResult,
   is_injected_module: &impl Fn(&[Tok<String>]) -> bool,
-) -> ProjectResult<()> {
+) -> ProjectResult<Preparsed> {
   // # Termination
   //
   // Every recursion of this function either
-  // - adds one of the files in the source directory to `table` or
+  // - adds one of the files in the source directory to `visited` or
   // - recursively traverses a directory tree
   // therefore eventually the function exits, assuming that the directory tree
   // contains no cycles.
 
-  // Termination: exit if entry already visited
-  if table.contains_key(abs_path) {
-    return Ok(());
-  }
-
   // try splitting the path to file, swallowing any IO errors
   let name_split = split_max_prefix(abs_path, &|p| {
     get_source(p).map(|l| l.is_code()).unwrap_or(false)
   });
   if let Some((filename, _)) = name_split {
+    // Termination: exit if entry already visited
+    if source.contains_key(filename) {
+      return Ok(all);
+    }
     // if the filename is valid, load, preparse and record this file
     let text = unwrap_or!(get_source(filename)? => Loaded::Code; {
       return Err(UnexpectedDirectory { path: filename.to_vec() }.rc())
     });
-    let preparsed = preparse(
+    source.insert(filename.to_vec(), LoadedSource { text: text.clone() });
-      Interner::extern_all(filename),
+    let preparsed = preparse(filename.to_vec(), text.as_str(), prelude, i)?;
-      text.as_str(),
-      prelude,
-      i,
-    )?;
-    table.insert(filename.to_vec(), LoadedSource {
-      text,
-      preparsed: preparsed.clone(),
-    });
     // recurse on all imported modules
-    preparsed.0.visit_all_imports(&mut |modpath, _module, import| {
+    // will be taken and returned by the closure. None iff an error is thrown
-      let abs_pathv =
+    all = preparsed.0.search_all(all, &mut |modpath,
-        import_abs_path(filename, modpath, &import.nonglob_path(), i)?;
+                                             module,
+                                             mut all|
+     -> ProjectResult<_> {
+      let details = unwrap_or!(module.extra.details(); return Ok(all));
+      for import in &details.imports {
+        let origin = &Location::Unknown;
+        let abs_pathv = import_abs_path(
+          filename,
+          modpath.clone(),
+          &import.nonglob_path(),
+          i,
+          origin,
+        )?;
         if abs_path.starts_with(&abs_pathv) {
-        return Ok(());
+          continue;
         }
         // recurse on imported module
-      load_abs_path_rec(
+        all = load_abs_path_rec(
           &abs_pathv,
-        table,
+          all,
+          source,
           prelude,
           i,
           get_source,
           is_injected_module,
-      )
+        )?;
-    })
+      }
+      Ok(all)
+    })?;
+    // Combine the trees
+    all.0.overlay(preparsed.0).map(Preparsed)
   } else {
     // If the path is not within a file, load it as directory
     let coll = match get_source(abs_path) {
@@ -81,25 +94,23 @@ fn load_abs_path_rec(
         let parent = abs_path.split_last().expect("import path nonzero").1;
         // exit without error if it was injected, or raise any IO error that was
         // previously swallowed
-        return if is_injected_module(parent) { Ok(()) } else { Err(e) };
+        return if is_injected_module(parent) { Ok(all) } else { Err(e) };
       },
     };
     // recurse on all files and folders within
     for item in coll.iter() {
-      let abs_subpath = (abs_path.iter())
+      let abs_subpath = pushed_ref(abs_path, i.i(item));
-        .cloned()
+      all = load_abs_path_rec(
-        .chain(iter::once(i.i(item)))
-        .collect::<Vec<_>>();
-      load_abs_path_rec(
         &abs_subpath,
-        table,
+        all,
+        source,
         prelude,
         i,
         get_source,
         is_injected_module,
-      )?
+      )?;
     }
-    Ok(())
+    Ok(all)
   }
 }
 
@@ -115,19 +126,22 @@ pub fn load_source<'a>(
   i: &Interner,
   get_source: &impl Fn(&[Tok<String>]) -> IOResult,
   is_injected_module: &impl Fn(&[Tok<String>]) -> bool,
-) -> ProjectResult<LoadedSourceTable> {
+) -> ProjectResult<(Preparsed, LoadedSourceTable)> {
   let mut table = LoadedSourceTable::new();
+  let mut all =
+    Preparsed(Module { extra: PreExtra::Dir, entries: HashMap::new() });
   let mut any_target = false;
   for target in targets {
     any_target |= true;
-    load_abs_path_rec(
+    all = load_abs_path_rec(
       target,
+      all,
       &mut table,
       prelude,
       i,
       get_source,
       is_injected_module,
-    )?
+    )?;
   }
-  if any_target { Ok(table) } else { Err(NoTargets.rc()) }
+  if any_target { Ok((all, table)) } else { Err(NoTargets.rc()) }
 }

src/pipeline/source_loader/loaded_source.rs

@@ -1,13 +1,11 @@
 use std::collections::HashMap;
 use std::rc::Rc;
 
-use super::preparse::Preparsed;
 use crate::representations::VName;
 
 #[derive(Debug)]
 pub struct LoadedSource {
   pub text: Rc<String>,
-  pub preparsed: Preparsed,
 }
 
 pub type LoadedSourceTable = HashMap<VName, LoadedSource>;

src/pipeline/source_loader/mod.rs

@@ -18,7 +18,8 @@
 mod load_source;
 mod loaded_source;
 mod preparse;
+mod types;
 
 pub use load_source::load_source;
 pub use loaded_source::{LoadedSource, LoadedSourceTable};
-pub use preparse::Preparsed;
+pub use types::{PreExtra, PreFileExt, PreItem, PreMod, PreSubExt, Preparsed};

src/pipeline/source_loader/preparse.rs

@@ -1,99 +1,169 @@
-use std::hash::Hash;
 use std::rc::Rc;
 
 use hashbrown::HashMap;
+use itertools::Itertools;
 
-use crate::ast::Constant;
+use super::types::{PreFileExt, PreItem, PreSubExt};
-use crate::error::{ProjectError, ProjectResult, VisibilityMismatch};
+use super::{PreExtra, Preparsed};
+use crate::ast::{Clause, Constant, Expr};
+use crate::error::{
+  ConflictingRoles, ProjectError, ProjectResult, VisibilityMismatch,
+};
 use crate::interner::Interner;
 use crate::parse::{self, ParsingContext};
-use crate::representations::sourcefile::{
+use crate::representations::sourcefile::{FileEntry, MemberKind};
-  imports, normalize_namespaces, FileEntry, Member,
-};
 use crate::representations::tree::{ModEntry, ModMember, Module};
+use crate::sourcefile::{FileEntryKind, Import, Member, ModuleBlock};
+use crate::utils::pushed::pushed;
+use crate::utils::{get_or_default, get_or_make};
+use crate::{Location, Tok, VName};
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+struct FileReport {
-pub struct Preparsed(pub Module<(), ()>);
+  entries: HashMap<Tok<String>, ModEntry<PreItem, PreExtra>>,
-
+  patterns: Vec<Vec<Expr<VName>>>,
-/// Add an internal flat name if it does not exist yet
+  imports: Vec<Import>,
-fn add_intern<K: Eq + Hash>(map: &mut HashMap<K, ModEntry<(), ()>>, k: K) {
-  let _ = map
-    .try_insert(k, ModEntry { exported: false, member: ModMember::Item(()) });
-}
-
-/// Add an exported flat name or export any existing entry
-fn add_export<K: Eq + Hash>(map: &mut HashMap<K, ModEntry<(), ()>>, k: K) {
-  if let Some(entry) = map.get_mut(&k) {
-    entry.exported = true
-  } else {
-    map.insert(k, ModEntry { exported: true, member: ModMember::Item(()) });
-  }
 }
 
 /// Convert source lines into a module
-fn to_module(src: &[FileEntry], prelude: &[FileEntry]) -> Module<(), ()> {
+fn to_module(
-  let all_src = || src.iter().chain(prelude.iter());
+  file: &[Tok<String>],
-  let imports = imports(all_src()).cloned().collect::<Vec<_>>();
+  path: VName,
-  let mut items = all_src()
+  src: Vec<FileEntry>,
-    .filter_map(|ent| match ent {
+  prelude: &[FileEntry],
-      FileEntry::Internal(Member::Module(ns)) => {
+) -> ProjectResult<FileReport> {
-        let member = ModMember::Sub(to_module(&ns.body, prelude));
+  let mut imports = Vec::new();
-        let entry = ModEntry { exported: false, member };
+  let mut patterns = Vec::new();
-        Some((ns.name.clone(), entry))
+  let mut items = HashMap::<Tok<String>, (bool, PreItem)>::new();
+  let mut to_export = HashMap::<Tok<String>, Vec<Location>>::new();
+  let mut submods =
+    HashMap::<Tok<String>, (bool, Vec<Location>, Vec<FileEntry>)>::new();
+  let entries = prelude.iter().cloned().chain(src.into_iter());
+  for FileEntry { kind, locations } in entries {
+    match kind {
+      FileEntryKind::Import(imp) => imports.extend(imp.into_iter()),
+      FileEntryKind::Export(names) =>
+        for (t, l) in names {
+          get_or_default(&mut to_export, &t).push(l)
         },
-      FileEntry::Exported(Member::Module(ns)) => {
+      FileEntryKind::Member(Member { exported, kind }) => match kind {
-        let member = ModMember::Sub(to_module(&ns.body, prelude));
+        MemberKind::Constant(Constant { name, .. }) => {
-        let entry = ModEntry { exported: true, member };
+          let (prev_exported, it) = get_or_default(&mut items, &name);
-        Some((ns.name.clone(), entry))
+          if it.has_value {
+            let err = ConflictingRoles { name: pushed(path, name), locations };
+            return Err(err.rc());
+          }
+          if let Some(loc) = locations.get(0) {
+            it.location = it.location.clone().or(loc.clone())
+          };
+          it.has_value = true;
+          *prev_exported |= exported;
         },
-      _ => None,
+        MemberKind::Module(ModuleBlock { name, body }) => {
+          if let Some((prev_exported, locv, entv)) = submods.get_mut(&name) {
+            if *prev_exported != exported {
+              let mut namespace = path;
+              namespace.push(name.clone());
+              let err = VisibilityMismatch { namespace, file: file.to_vec() };
+              return Err(err.rc());
+            }
+            locv.extend(locations.into_iter());
+            entv.extend(body.into_iter())
+          } else {
+            submods.insert(name.clone(), (exported, locations, body.clone()));
+          }
+        },
+        MemberKind::Operators(ops) =>
+          for op in ops {
+            let (prev_exported, it) = get_or_default(&mut items, &op);
+            if let Some(loc) = locations.get(0) {
+              it.location = it.location.clone().or(loc.clone())
+            }
+            *prev_exported |= exported;
+            it.is_op = true;
+          },
+        MemberKind::Rule(r) => {
+          patterns.push(r.pattern.clone());
+          if exported {
+            for ex in r.pattern {
+              ex.search_all(&mut |ex| {
+                if let Clause::Name(vname) = &ex.value {
+                  if let Ok(name) = vname.iter().exactly_one() {
+                    get_or_default(&mut to_export, name)
+                      .push(ex.location.clone());
+                  }
+                }
+                None::<()>
+              });
+            }
+          }
+        },
+      },
+      _ => (),
+    }
+  }
+  let mut entries = HashMap::with_capacity(items.len() + submods.len());
+  entries.extend(items.into_iter().map(|(name, (exported, it))| {
+    (name, ModEntry { member: ModMember::Item(it), exported })
+  }));
+  for (subname, (exported, locations, body)) in submods {
+    let mut name = path.clone();
+    entries
+      .try_insert(subname.clone(), ModEntry {
+        member: ModMember::Sub({
+          name.push(subname);
+          let FileReport { imports, entries: items, patterns } =
+            to_module(file, name.clone(), body, prelude)?;
+          Module {
+            entries: items,
+            extra: PreExtra::Submod(PreSubExt { imports, patterns }),
+          }
+        }),
+        exported,
       })
-    .collect::<HashMap<_, _>>();
+      .map_err(|_| ConflictingRoles { locations, name }.rc())?;
-  for file_entry in all_src() {
-    match file_entry {
-      FileEntry::Comment(_)
-      | FileEntry::Import(_)
-      | FileEntry::Internal(Member::Module(_))
-      | FileEntry::Exported(Member::Module(_)) => (),
-      FileEntry::Export(tokv) =>
-        for tok in tokv {
-          add_export(&mut items, tok.clone())
-        },
-      FileEntry::Internal(Member::Constant(Constant { name, .. })) =>
-        add_intern(&mut items, name.clone()),
-      FileEntry::Exported(Member::Constant(Constant { name, .. })) =>
-        add_export(&mut items, name.clone()),
-      FileEntry::Internal(Member::Rule(rule)) => {
-        let names = rule.collect_single_names();
-        for name in names {
-          add_intern(&mut items, name)
   }
-      },
+  for (item, locations) in to_export {
-      FileEntry::Exported(Member::Rule(rule)) => {
+    get_or_make(&mut entries, &item, || ModEntry {
-        let names = rule.collect_single_names();
+      member: ModMember::Item(PreItem {
-        for name in names {
+        is_op: false,
-          add_export(&mut items, name)
+        has_value: false,
+        location: locations[0].clone(),
+      }),
+      exported: true,
+    })
+    .exported = true
   }
-      },
+  Ok(FileReport { entries, imports, patterns })
-    }
-  }
-  Module { imports, items, extra: () }
 }
 
 /// Preparse the module. At this stage, only the imports and
 /// names defined by the module can be parsed
 pub fn preparse(
-  file: Vec<String>,
+  file: VName,
   source: &str,
   prelude: &[FileEntry],
   i: &Interner,
 ) -> ProjectResult<Preparsed> {
   // Parse with no operators
-  let ctx = ParsingContext::<&str>::new(&[], i, Rc::new(file.clone()));
+  let ctx = ParsingContext::new(&[], i, Rc::new(file.clone()));
   let entries = parse::parse2(source, ctx)?;
-  let normalized = normalize_namespaces(Box::new(entries.into_iter()))
+  let FileReport { entries, imports, patterns } =
-    .map_err(|namespace| {
+    to_module(&file, file.clone(), entries, prelude)?;
-      VisibilityMismatch { namespace, file: Rc::new(file.clone()) }.rc()
+  let mut module = Module {
-    })?;
+    entries,
-  Ok(Preparsed(to_module(&normalized, prelude)))
+    extra: PreExtra::File(PreFileExt {
+      details: PreSubExt { patterns, imports },
+      name: file.clone(),
+    }),
+  };
+  for name in file.iter().rev() {
+    module = Module {
+      extra: PreExtra::Dir,
+      entries: HashMap::from([(name.clone(), ModEntry {
+        exported: true,
+        member: ModMember::Sub(module),
+      })]),
+    };
+  }
+  Ok(Preparsed(module))
 }

src/pipeline/source_loader/types.rs

@@ -0,0 +1,92 @@
+use std::fmt::Display;
+use std::ops::Add;
+
+use crate::ast::Expr;
+use crate::error::ProjectResult;
+use crate::sourcefile::Import;
+use crate::tree::Module;
+use crate::{Interner, Location, VName};
+
+#[derive(Debug, Clone)]
+pub struct PreItem {
+  pub is_op: bool,
+  pub has_value: bool,
+  pub location: Location,
+}
+
+impl Display for PreItem {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let Self { has_value, is_op, location } = self;
+    let description = match (is_op, has_value) {
+      (true, true) => "operator with value",
+      (true, false) => "operator",
+      (false, true) => "value",
+      (false, false) => "keyword",
+    };
+    write!(f, "{description} {location}")
+  }
+}
+
+impl Default for PreItem {
+  fn default() -> Self {
+    PreItem { is_op: false, has_value: false, location: Location::Unknown }
+  }
+}
+
+#[derive(Debug, Clone)]
+pub struct PreSubExt {
+  pub imports: Vec<Import>,
+  pub patterns: Vec<Vec<Expr<VName>>>,
+}
+
+#[derive(Debug, Clone)]
+pub struct PreFileExt {
+  pub name: VName,
+  pub details: PreSubExt,
+}
+
+#[derive(Debug, Clone)]
+pub enum PreExtra {
+  File(PreFileExt),
+  Submod(PreSubExt),
+  Dir,
+}
+
+impl PreExtra {
+  /// If the module is not a directory, returns the source-only details
+  pub fn details(&self) -> Option<&PreSubExt> {
+    match self {
+      Self::Submod(sub) => Some(sub),
+      Self::File(PreFileExt { details, .. }) => Some(details),
+      Self::Dir => None,
+    }
+  }
+}
+
+impl Add for PreExtra {
+  type Output = ProjectResult<Self>;
+
+  fn add(self, rhs: Self) -> Self::Output {
+    match (self, rhs) {
+      (alt, Self::Dir) | (Self::Dir, alt) => Ok(alt),
+      (Self::File(_) | Self::Submod(_), Self::File(_) | Self::Submod(_)) =>
+        panic!("Each file should be parsed once."),
+    }
+  }
+}
+
+impl Display for PreExtra {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::Dir => write!(f, "Directory"),
+      Self::File(PreFileExt { name, .. }) =>
+        write!(f, "File({}.orc)", Interner::extern_all(name).join("/")),
+      Self::Submod(_) => write!(f, "Submodule"),
+    }
+  }
+}
+
+pub type PreMod = Module<PreItem, PreExtra>;
+
+#[derive(Debug, Clone)]
+pub struct Preparsed(pub PreMod);

src/representations/ast.rs

@@ -17,6 +17,7 @@ use super::location::Location;
 use super::namelike::{NameLike, VName};
 use super::primitive::Primitive;
 use crate::interner::Tok;
+use crate::parse::print_nat16;
 use crate::utils::map_rc;
 
 /// A [Clause] with associated metadata
@@ -365,7 +366,7 @@ impl Rule<VName> {
 
   /// Return a list of all names that don't contain a namespace separator `::`.
   /// These are exported when the rule is exported
-  pub fn collect_single_names(&self) -> Vec<Tok<String>> {
+  pub fn collect_single_names(&self) -> VName {
     let mut names = Vec::new();
     for e in self.pattern.iter() {
       e.search_all(&mut |e| {
@@ -385,9 +386,9 @@ impl<N: NameLike> Display for Rule<N> {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
     write!(
       f,
-      "{} ={}=> {}",
+      "rule {} ={}=> {}",
       self.pattern.iter().join(" "),
-      self.prio,
+      print_nat16(self.prio),
       self.template.iter().join(" ")
     )
   }
@@ -404,6 +405,6 @@ pub struct Constant {
 
 impl Display for Constant {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-    write!(f, "{} := {}", *self.name, self.value)
+    write!(f, "const {} := {}", *self.name, self.value)
   }
 }

src/representations/ast_to_postmacro.rs

@@ -34,8 +34,8 @@ impl ProjectError for Error {
   fn description(&self) -> &str {
     match self.kind {
       ErrorKind::BadGroup(_) =>
-        "Only `(...)` may be converted to typed lambdas. `[...]` and `{{...}}` \
+        "Only `(...)` may be converted to postmacro. `[...]` and `{...}` left \
-         left in the code are signs of incomplete macro execution",
+         in the code are signs of incomplete macro execution",
       ErrorKind::EmptyS => "`()` as a clause is meaningless in lambda calculus",
       ErrorKind::InvalidArg => "Argument names can only be Name nodes",
       ErrorKind::Placeholder =>

src/representations/const_tree.rs

@@ -2,14 +2,15 @@ use std::ops::Add;
 
 use hashbrown::HashMap;
 
+use super::project::{ItemKind, ProjectItem};
 use crate::ast::{Clause, Expr};
 use crate::foreign::{Atom, Atomic, ExternFn};
 use crate::interner::Tok;
 use crate::representations::location::Location;
-use crate::representations::project::{ProjectExt, ProjectModule, ProjectTree};
+use crate::representations::project::{ProjectExt, ProjectMod, ProjectTree};
 use crate::representations::tree::{ModEntry, ModMember, Module};
 use crate::representations::{Primitive, VName};
-use crate::utils::{pushed, Substack};
+use crate::utils::Substack;
 
 /// A lightweight module tree that can be built declaratively by hand to
 /// describe libraries of external functions in Rust. It implements [Add] for
@@ -90,29 +91,28 @@ fn from_const_tree_rec(
   path: Substack<Tok<String>>,
   consts: HashMap<Tok<String>, ConstTree>,
   file: &[Tok<String>],
-) -> ProjectModule<VName> {
+) -> ProjectMod<VName> {
   let mut items = HashMap::new();
-  let path_v = path.iter().rev_vec_clone();
   for (name, item) in consts {
     items.insert(name.clone(), ModEntry {
       exported: true,
       member: match item {
-        ConstTree::Const(c) => ModMember::Item(c),
+        ConstTree::Const(c) => ModMember::Item(ProjectItem {
+          kind: ItemKind::Const(c),
+          is_op: false,
+        }),
         ConstTree::Tree(t) =>
           ModMember::Sub(from_const_tree_rec(path.push(name), t, file)),
       },
     });
   }
-  let exports = (items.keys())
-    .map(|name| (name.clone(), pushed(&path_v, name.clone())))
-    .collect();
   Module {
-    items,
+    entries: items,
-    imports: vec![],
     extra: ProjectExt {
-      exports,
       file: Some(file.to_vec()),
-      ..Default::default()
+      imports_from: HashMap::new(),
+      rules: Vec::new(),
+      path: path.iter().rev_vec_clone(),
     },
   }
 }

src/representations/interpreted.rs

@@ -15,8 +15,6 @@ use super::primitive::Primitive;
 use super::Literal;
 use crate::Sym;
 
-// TODO: implement Debug, Eq and Hash with cycle detection
-
 /// An expression with metadata
 pub struct Expr {
   /// The actual value

src/representations/location.rs

@@ -1,21 +1,23 @@
-use std::fmt::Display;
+use std::fmt::{Debug, Display};
 use std::ops::Range;
 use std::rc::Rc;
 
 use itertools::Itertools;
 
+use crate::VName;
+
 /// A location in a file, identifies a sequence of suspect characters for any
 /// error. Meaningful within the context of a project.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash)]
 pub enum Location {
   /// Location information lost or code generated on the fly
   Unknown,
   /// Only the file is known
-  File(Rc<Vec<String>>),
+  File(Rc<VName>),
   /// Character slice of the code
   Range {
     /// Argument to the file loading callback that produced this code
-    file: Rc<Vec<String>>,
+    file: Rc<VName>,
     /// Index of the unicode code points associated with the code
     range: Range<usize>,
     /// The full source code as received by the parser
@@ -34,7 +36,7 @@ impl Location {
   }
 
   /// File, if known
-  pub fn file(&self) -> Option<Rc<Vec<String>>> {
+  pub fn file(&self) -> Option<Rc<VName>> {
     if let Self::File(file) | Self::Range { file, .. } = self {
       Some(file.clone())
     } else {
@@ -102,6 +104,12 @@ impl Display for Location {
   }
 }
 
+impl Debug for Location {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    write!(f, "{self}")
+  }
+}
+
 fn pos2lc(s: &str, i: usize) -> (usize, usize) {
   s.chars().take(i).fold((1, 1), |(line, col), char| {
     if char == '\n' { (line + 1, 1) } else { (line, col + 1) }

src/representations/mod.rs

@@ -12,13 +12,13 @@ pub mod postmacro_to_interpreted;
 pub mod primitive;
 pub mod project;
 pub mod sourcefile;
-pub mod tree;
 mod string;
+pub mod tree;
 
 pub use const_tree::{from_const_tree, ConstTree};
-pub use string::OrcString;
 pub use literal::Literal;
 pub use location::Location;
 pub use namelike::{NameLike, Sym, VName};
 pub use path_set::PathSet;
 pub use primitive::Primitive;
+pub use string::OrcString;

src/representations/namelike.rs

@@ -1,3 +1,4 @@
+use std::fmt::Debug;
 use std::hash::Hash;
 
 use crate::interner::{Interner, Tok};
@@ -14,11 +15,11 @@ pub type VName = Vec<Tok<String>>;
 /// These names are always absolute.
 ///
 /// See also [VName]
-pub type Sym = Tok<Vec<Tok<String>>>;
+pub type Sym = Tok<VName>;
 
 /// An abstraction over tokenized vs non-tokenized names so that they can be
 /// handled together in datastructures
-pub trait NameLike: 'static + Clone + Eq + Hash {
+pub trait NameLike: 'static + Clone + Eq + Hash + Debug {
   /// Fully resolve the name for printing
   fn to_strv(&self) -> Vec<String>;
 }

src/representations/project.rs

@@ -1,3 +1,4 @@
+use std::fmt::Display;
 use std::ops::Add;
 
 use hashbrown::HashMap;
@@ -7,51 +8,129 @@ use crate::interner::{Interner, Tok};
 use crate::representations::tree::{ModMember, Module};
 use crate::representations::NameLike;
 use crate::tree::ModEntry;
+use crate::utils::never::{always, Always};
 use crate::utils::Substack;
 use crate::{Sym, VName};
 
+#[derive(Debug, Clone)]
+pub enum ItemKind<N: NameLike> {
+  /// An imported symbol or module. The value is the absolute path of
+  /// the symbol that should be used instead of this one.
+  ///
+  /// Notice that this is different from [ProjectExt::imports_from] the values
+  /// of which do not include the name they're keyed with.
+  Alias(VName),
+  None,
+  Const(Expr<N>),
+}
+
+impl<N: NameLike> Default for ItemKind<N> {
+  fn default() -> Self {
+    Self::None
+  }
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct ProjectItem<N: NameLike> {
+  pub kind: ItemKind<N>,
+  pub is_op: bool,
+}
+
+impl<N: NameLike> Display for ProjectItem<N> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match &self.kind {
+      ItemKind::None => match self.is_op {
+        true => write!(f, "operator"),
+        false => write!(f, "keyword"),
+      },
+      ItemKind::Const(c) => match self.is_op {
+        true => write!(f, "operator with value {c}"),
+        false => write!(f, "constant {c}"),
+      },
+      ItemKind::Alias(alias) => {
+        let origin = Interner::extern_all(alias).join("::");
+        match self.is_op {
+          true => write!(f, "operator alias to {origin}"),
+          false => write!(f, "alias to {origin}"),
+        }
+      },
+    }
+  }
+}
+
+/// Information about an imported symbol
+#[derive(Debug, Clone)]
+pub struct ImpReport<N: NameLike> {
+  /// Absolute path of the module the symbol is imported from
+  pub source: N,
+  /// Whether this symbol should be treated as an operator for the purpose of
+  /// parsing
+  pub is_op: bool,
+}
+
 /// Additional data about a loaded module beyond the list of constants and
 /// submodules
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug)]
 pub struct ProjectExt<N: NameLike> {
-  /// Pairs each foreign token to the module it was imported from
+  /// Full path leading to this module
-  pub imports_from: HashMap<Tok<String>, N>,
+  pub path: VName,
-  /// Pairs each exported token to its original full name
+  /// Pairs each imported token to the absolute path of the module it is
-  pub exports: HashMap<Tok<String>, N>,
+  /// imported from. The path does not include the name of referencedthe
+  /// symbol.
+  pub imports_from: HashMap<Tok<String>, ImpReport<N>>,
   /// All rules defined in this module, exported or not
   pub rules: Vec<Rule<N>>,
   /// Filename, if known, for error reporting
-  pub file: Option<Vec<Tok<String>>>,
+  pub file: Option<VName>,
 }
 
 impl<N: NameLike> Add for ProjectExt<N> {
-  type Output = Self;
+  type Output = Always<Self>;
 
   fn add(mut self, rhs: Self) -> Self::Output {
-    let ProjectExt { imports_from, exports, rules, file } = rhs;
+    let ProjectExt { path, imports_from, rules, file } = rhs;
+    if path != self.path {
+      panic!(
+        "Differently named trees overlain: {} vs {}",
+        Interner::extern_all(&path).join("::"),
+        Interner::extern_all(&self.path).join("::")
+      )
+    }
     self.imports_from.extend(imports_from.into_iter());
-    self.exports.extend(exports.into_iter());
     self.rules.extend(rules.into_iter());
     if file.is_some() {
       self.file = file
     }
-    self
+    always(self)
   }
 }
 
+impl<N: NameLike> Display for ProjectExt<N> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    f.debug_struct("Project-module extras")
+      .field("path", &Interner::extern_all(&self.path).join("::"))
+      .field("imports_from", &self.imports_from)
+      .field("rules", &self.rules)
+      .field("file", &(Interner::extern_all(&self.path).join("/") + ".orc"))
+      .finish()
+  }
+}
+
+/// A child to a [ProjectMod]
+pub type ProjectEntry<N> = ModEntry<ProjectItem<N>, ProjectExt<N>>;
 /// A node in the tree describing the project
-pub type ProjectModule<N> = Module<Expr<N>, ProjectExt<N>>;
+pub type ProjectMod<N> = Module<ProjectItem<N>, ProjectExt<N>>;
 
 /// Module corresponding to the root of a project
 #[derive(Debug, Clone)]
-pub struct ProjectTree<N: NameLike>(pub ProjectModule<N>);
+pub struct ProjectTree<N: NameLike>(pub ProjectMod<N>);
 
 fn collect_rules_rec<N: NameLike>(
   bag: &mut Vec<Rule<N>>,
-  module: &ProjectModule<N>,
+  module: &ProjectMod<N>,
 ) {
   bag.extend(module.extra.rules.iter().cloned());
-  for item in module.items.values() {
+  for item in module.entries.values() {
     if let ModMember::Sub(module) = &item.member {
       collect_rules_rec(bag, module);
     }
@@ -69,12 +148,13 @@ pub fn collect_rules<N: NameLike>(project: &ProjectTree<N>) -> Vec<Rule<N>> {
 fn collect_consts_rec<N: NameLike>(
   path: Substack<Tok<String>>,
   bag: &mut HashMap<Sym, Expr<N>>,
-  module: &ProjectModule<N>,
+  module: &ProjectMod<N>,
   i: &Interner,
 ) {
-  for (key, entry) in module.items.iter() {
+  for (key, entry) in module.entries.iter() {
     match &entry.member {
-      ModMember::Item(expr) => {
+      ModMember::Item(it) =>
+        if let ItemKind::Const(expr) = &it.kind {
           let mut name = path.iter().rev_vec_clone();
           name.push(key.clone());
           bag.insert(i.i(&name), expr.clone());
@@ -96,30 +176,34 @@ pub fn collect_consts<N: NameLike>(
 }
 
 fn vname_to_sym_tree_rec(
-  tree: ProjectModule<VName>,
+  tree: ProjectMod<VName>,
   i: &Interner,
-) -> ProjectModule<Sym> {
+) -> ProjectMod<Sym> {
   let process_expr = |ex: Expr<VName>| ex.transform_names(&|n| i.i(&n));
-  ProjectModule {
+  ProjectMod {
-    imports: tree.imports,
+    entries: (tree.entries.into_iter())
-    items: (tree.items.into_iter())
       .map(|(k, ModEntry { exported, member })| {
         (k, ModEntry {
           exported,
           member: match member {
             ModMember::Sub(module) =>
               ModMember::Sub(vname_to_sym_tree_rec(module, i)),
-            ModMember::Item(ex) => ModMember::Item(process_expr(ex)),
+            ModMember::Item(ex) => ModMember::Item(ProjectItem {
+              is_op: ex.is_op,
+              kind: match ex.kind {
+                ItemKind::None => ItemKind::None,
+                ItemKind::Alias(n) => ItemKind::Alias(n),
+                ItemKind::Const(ex) => ItemKind::Const(process_expr(ex)),
+              },
+            }),
           },
         })
       })
       .collect(),
     extra: ProjectExt {
+      path: tree.extra.path,
       imports_from: (tree.extra.imports_from.into_iter())
-        .map(|(k, v)| (k, i.i(&v)))
+        .map(|(k, v)| (k, ImpReport { is_op: v.is_op, source: i.i(&v.source) }))
-        .collect(),
-      exports: (tree.extra.exports.into_iter())
-        .map(|(k, v)| (k, i.i(&v)))
         .collect(),
       rules: (tree.extra.rules.into_iter())
         .map(|Rule { pattern, prio, template }| Rule {

src/representations/sourcefile.rs

@@ -1,12 +1,16 @@
 //! Building blocks of a source file
+use std::fmt::Display;
 use std::iter;
 
 use itertools::{Either, Itertools};
 
 use super::namelike::VName;
 use crate::ast::{Constant, Rule};
+use crate::error::{ProjectError, ProjectResult, TooManySupers};
 use crate::interner::{Interner, Tok};
+use crate::utils::pushed::pushed;
 use crate::utils::{unwrap_or, BoxedIter};
+use crate::Location;
 
 /// An import pointing at another module, either specifying the symbol to be
 /// imported or importing all available symbols with a globstar (*)
@@ -21,6 +25,8 @@ pub struct Import {
   pub path: VName,
   /// If name is None, this is a wildcard import
   pub name: Option<Tok<String>>,
+  /// Location of the final name segment, which uniquely identifies this name
+  pub location: Location,
 }
 impl Import {
   /// Get the preload target space for this import - the prefix below
@@ -28,7 +34,7 @@ impl Import {
   ///
   /// Returns the path if this is a glob import, or the path plus the
   /// name if this is a specific import
-  pub fn nonglob_path(&self) -> Vec<Tok<String>> {
+  pub fn nonglob_path(&self) -> VName {
     let mut path_vec = self.path.clone();
     if let Some(n) = &self.name {
       path_vec.push(n.clone())
@@ -37,6 +43,14 @@ impl Import {
   }
 }
 
+impl Display for Import {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let paths = self.path.iter().map(|t| &**t).join("::");
+    let names = self.name.as_ref().map(|t| t.as_str()).unwrap_or("*");
+    write!(f, "{paths}::{names}")
+  }
+}
+
 /// A namespace block
 #[derive(Debug, Clone)]
 pub struct ModuleBlock {
@@ -46,9 +60,16 @@ pub struct ModuleBlock {
   pub body: Vec<FileEntry>,
 }
 
-/// Things that may be prefixed with an export
+impl Display for ModuleBlock {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let bodys = self.body.iter().map(|e| e.to_string()).join("\n");
+    write!(f, "module {} {{\n{}\n}}", self.name, bodys)
+  }
+}
+
+/// see [Member]
 #[derive(Debug, Clone)]
-pub enum Member {
+pub enum MemberKind {
   /// A substitution rule. Rules apply even when they're not in scope, if the
   /// absolute names are present eg. because they're produced by other rules
   Rule(Rule<VName>),
@@ -56,22 +77,81 @@ pub enum Member {
   Constant(Constant),
   /// A prefixed set of other entries
   Module(ModuleBlock),
+  /// Operator declarations
+  Operators(Vec<Tok<String>>),
 }
 
-/// Anything we might encounter in a file
+impl Display for MemberKind {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::Operators(opv) =>
+        write!(f, "operators[{}]", opv.iter().map(|t| &**t).join(" ")),
+      Self::Constant(c) => c.fmt(f),
+      Self::Module(m) => m.fmt(f),
+      Self::Rule(r) => r.fmt(f),
+    }
+  }
+}
+
+/// Things that may be prefixed with an export
+/// see [MemberKind]
 #[derive(Debug, Clone)]
-pub enum FileEntry {
+pub struct Member {
+  /// Various members
+  pub kind: MemberKind,
+  /// Whether this member is exported or not
+  pub exported: bool,
+}
+
+impl Display for Member {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self { exported: true, kind } => write!(f, "export {kind}"),
+      Self { exported: false, kind } => write!(f, "{kind}"),
+    }
+  }
+}
+
+/// See [FileEntry]
+#[derive(Debug, Clone)]
+pub enum FileEntryKind {
   /// Imports one or all names in a module
   Import(Vec<Import>),
   /// Comments are kept here in case dev tooling wants to parse documentation
   Comment(String),
-  /// An element visible to the outside
+  /// An element with visibility information
-  Exported(Member),
+  Member(Member),
-  /// An element only visible from local code
-  Internal(Member),
   /// A list of tokens exported explicitly. This can also create new exported
   /// tokens that the local module doesn't actually define a role for
-  Export(Vec<Tok<String>>),
+  Export(Vec<(Tok<String>, Location)>),
+}
+
+impl Display for FileEntryKind {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::Comment(s) => write!(f, "--[{s}]--"),
+      Self::Export(s) =>
+        write!(f, "export ::({})", s.iter().map(|t| &**t.0).join(", ")),
+      Self::Member(member) => write!(f, "{member}"),
+      Self::Import(i) =>
+        write!(f, "import ({})", i.iter().map(|i| i.to_string()).join(", ")),
+    }
+  }
+}
+
+/// Anything the parser might encounter in a file. See [FileEntryKind]
+#[derive(Debug, Clone)]
+pub struct FileEntry {
+  /// What we encountered
+  pub kind: FileEntryKind,
+  /// Where we encountered it
+  pub locations: Vec<Location>,
+}
+
+impl Display for FileEntry {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    self.kind.fmt(f)
+  }
 }
 
 /// Summarize all imports from a file in a single list of qualified names
@@ -79,8 +159,8 @@ pub fn imports<'a>(
   src: impl Iterator<Item = &'a FileEntry> + 'a,
 ) -> impl Iterator<Item = &'a Import> + 'a {
   src
-    .filter_map(|ent| match ent {
+    .filter_map(|ent| match &ent.kind {
-      FileEntry::Import(impv) => Some(impv.iter()),
+      FileEntryKind::Import(impv) => Some(impv.iter()),
       _ => None,
     })
     .flatten()
@@ -90,56 +170,56 @@ pub fn imports<'a>(
 /// Error if they're inconsistently exported
 pub fn normalize_namespaces(
   src: BoxedIter<FileEntry>,
-) -> Result<Vec<FileEntry>, Vec<Tok<String>>> {
+) -> Result<Vec<FileEntry>, VName> {
   let (mut namespaces, mut rest) = src
-    .partition_map::<Vec<_>, Vec<_>, _, _, _>(|ent| match ent {
+    .partition_map::<Vec<_>, Vec<_>, _, _, _>(|ent| {
-      FileEntry::Exported(Member::Module(ns)) => Either::Left((true, ns)),
+      match ent {
-      FileEntry::Internal(Member::Module(ns)) => Either::Left((false, ns)),
+        FileEntry {
-      other => Either::Right(other),
+          kind: FileEntryKind::Member(Member {
+        kind: MemberKind::Module(ns),
+        exported,
+      }),
+          locations
+        } => Either::Left((exported, ns, locations)),
+        ent => Either::Right(ent)
+      }
     });
   // Combine namespace blocks with the same name
-  namespaces.sort_unstable_by_key(|(_, ns)| ns.name.clone());
+  namespaces.sort_unstable_by_key(|(_, ns, _)| ns.name.clone());
   let mut lumped = namespaces
     .into_iter()
-    .group_by(|(_, ns)| ns.name.clone())
+    .group_by(|(_, ns, _)| ns.name.clone())
     .into_iter()
     .map(|(name, grp)| {
-      let mut any_exported = false;
+      let mut exported = false;
-      let mut any_internal = false;
+      let mut internal = false;
-      let grp_src = grp
+      let mut grouped_source = Vec::new();
-        .into_iter()
+      let mut locations = Vec::new();
-        .map(|(exported, ns)| {
+      for (inst_exported, ns, locs) in grp {
-          if exported {
+        if inst_exported {
-            any_exported = true
+          exported = true
         } else {
-            any_internal = true
+          internal = true
         };
-          ns // Impure map is less than ideal but works
+        grouped_source.extend(ns.body.into_iter());
-        })
+        locations.extend(locs.into_iter());
-        .flat_map(|ns| ns.body.into_iter());
-      // Apply the function to the contents of these blocks too
-      let body = normalize_namespaces(Box::new(grp_src)).map_err(|mut e| {
-        e.push(name.clone());
-        e
-      })?;
-      let member = Member::Module(ModuleBlock { name: name.clone(), body });
-      match (any_exported, any_internal) {
-        (true, true) => Err(vec![name]),
-        (true, false) => Ok(FileEntry::Exported(member)),
-        (false, true) => Ok(FileEntry::Internal(member)),
-        (false, false) => unreachable!("The group cannot be empty"),
       }
+      if exported == internal {
+        debug_assert!(exported && internal, "Both false is impossible");
+        return Err(vec![name]);
+      }
+      // Apply the function to the contents of these blocks too
+      let body = normalize_namespaces(Box::new(grouped_source.into_iter()))
+        .map_err(|e| pushed(e, name.clone()))?;
+      let kind = MemberKind::Module(ModuleBlock { name, body });
+      let kind = FileEntryKind::Member(Member { kind, exported });
+      Ok(FileEntry { kind, locations })
     })
     .collect::<Result<Vec<_>, _>>()?;
   rest.append(&mut lumped);
   Ok(rest)
 }
 
-/// Produced by [absolute_path] if there are more `super` segments in the
-/// import than the length of the current absolute path
-#[derive(Debug, Clone)]
-pub struct TooManySupers;
-
 /// Turn a relative (import) path into an absolute path.
 /// If the import path is empty, the return value is also empty.
 ///
@@ -151,22 +231,33 @@ pub fn absolute_path(
   abs_location: &[Tok<String>],
   rel_path: &[Tok<String>],
   i: &Interner,
-) -> Result<Vec<Tok<String>>, TooManySupers> {
+  location: &Location,
+) -> ProjectResult<VName> {
+  absolute_path_rec(abs_location, rel_path, i).ok_or_else(|| {
+    TooManySupers { path: rel_path.to_vec(), location: location.clone() }.rc()
+  })
+}
+
+fn absolute_path_rec(
+  abs_location: &[Tok<String>],
+  rel_path: &[Tok<String>],
+  i: &Interner,
+) -> Option<VName> {
   let (head, tail) = unwrap_or!(rel_path.split_first();
-    return Ok(vec![])
+    return Some(vec![])
   );
   if *head == i.i("super") {
-    let (_, new_abs) = abs_location.split_last().ok_or(TooManySupers)?;
+    let (_, new_abs) = abs_location.split_last()?;
     if tail.is_empty() {
-      Ok(new_abs.to_vec())
+      Some(new_abs.to_vec())
     } else {
       let new_rel =
         iter::once(i.i("self")).chain(tail.iter().cloned()).collect::<Vec<_>>();
-      absolute_path(new_abs, &new_rel, i)
+      absolute_path_rec(new_abs, &new_rel, i)
     }
   } else if *head == i.i("self") {
-    Ok(abs_location.iter().chain(tail.iter()).cloned().collect())
+    Some(abs_location.iter().chain(tail.iter()).cloned().collect())
   } else {
-    Ok(rel_path.to_vec())
+    Some(rel_path.to_vec())
   }
 }

src/representations/string.rs

@@ -1,16 +1,30 @@
+use std::fmt::Debug;
 use std::hash::Hash;
 use std::ops::Deref;
 use std::rc::Rc;
 
 use crate::Tok;
 
-#[derive(Clone, Debug, Eq)]
+/// An Orchid string which may or may not be interned
+#[derive(Clone, Eq)]
 pub enum OrcString {
+  /// An interned string. Equality-conpared by reference.
   Interned(Tok<String>),
+  /// An uninterned bare string. Equality-compared by character
   Runtime(Rc<String>),
 }
 
+impl Debug for OrcString {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::Runtime(s) => write!(f, "r\"{s}\""),
+      Self::Interned(t) => write!(f, "i\"{t}\""),
+    }
+  }
+}
+
 impl OrcString {
+  /// Clone out the plain Rust [String]
   pub fn get_string(&self) -> String {
     self.as_str().to_owned()
   }

src/representations/tree.rs

@@ -1,14 +1,17 @@
 //! Generic module tree structure
 //!
 //! Used by various stages of the pipeline with different parameters
+use std::fmt::{Debug, Display};
 use std::ops::Add;
+use std::rc::Rc;
 
-use duplicate::duplicate_item;
 use hashbrown::HashMap;
 
-use super::sourcefile::Import;
+use super::Location;
+use crate::error::ProjectError;
 use crate::interner::Tok;
-use crate::utils::Substack;
+use crate::utils::{BoxedIter, Substack};
+use crate::{Interner, VName};
 
 /// The member in a [ModEntry] which is associated with a name in a [Module]
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -27,121 +30,247 @@ pub struct ModEntry<TItem: Clone, TExt: Clone> {
   /// Whether the member is visible to modules other than the parent
   pub exported: bool,
 }
+impl<TItem: Clone, TExt: Clone> ModEntry<TItem, TExt> {
+  /// Returns the item in this entry if it contains one.
+  pub fn item(&self) -> Option<&TItem> {
+    match &self.member {
+      ModMember::Item(it) => Some(it),
+      ModMember::Sub(_) => None,
+    }
+  }
+}
 
 /// A module, containing imports,
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Module<TItem: Clone, TExt: Clone> {
-  /// Import statements present this module
-  pub imports: Vec<Import>,
   /// Submodules and items by name
-  pub items: HashMap<Tok<String>, ModEntry<TItem, TExt>>,
+  pub entries: HashMap<Tok<String>, ModEntry<TItem, TExt>>,
   /// Additional information associated with the module
   pub extra: TExt,
 }
 
-/// Possible causes why the path could not be walked
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum WalkErrorKind {
-  /// `require_exported` was set to `true` and a module wasn't exported
-  Private,
-  /// A module was not found
-  Missing,
-}
-
-/// Error produced by [Module::walk]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct WalkError {
-  /// The 0-based index of the offending segment
-  pub pos: usize,
-  /// The cause of the error
-  pub kind: WalkErrorKind,
-}
-
 /// The path taken to reach a given module
 pub type ModPath<'a> = Substack<'a, Tok<String>>;
 
 impl<TItem: Clone, TExt: Clone> Module<TItem, TExt> {
+  /// If the argument is false, returns all child names.
+  /// If the argument is  true, returns all public child names.
+  pub fn keys(&self, public: bool) -> BoxedIter<Tok<String>> {
+    match public {
+      false => Box::new(self.entries.keys().cloned()),
+      true => Box::new(
+        (self.entries.iter())
+          .filter(|(_, v)| v.exported)
+          .map(|(k, _)| k.clone()),
+      ),
+    }
+  }
+
   /// Return the module at the end of the given path
-  #[allow(clippy::needless_arbitrary_self_type)] // duplicate
+  pub fn walk_ref<'a: 'b, 'b>(
-  #[duplicate_item(
+    &'a self,
-    method      reference(type) dereference(expr) map_method;
+    prefix: &'b [Tok<String>],
-    [walk]      [type]          [expr]            [remove];
+    path: &'b [Tok<String>],
-    [walk_ref]  [&type]         [*expr]           [get];
+    public: bool,
-    [walk_mut]  [&mut type]     [*expr]           [get_mut];
+  ) -> Result<&'a Self, WalkError<'b>> {
-  )]
+    let mut module = self;
-  pub fn method(
-    self: reference([Self]),
-    path: &[Tok<String>],
-    require_exported: bool,
-  ) -> Result<reference([Self]), WalkError> {
-    let mut cur = self;
     for (pos, step) in path.iter().enumerate() {
-      if let Some(ModEntry { member: ModMember::Sub(next), exported }) =
+      let kind = match module.entries.get(step) {
-        cur.items.map_method(step)
+        None => ErrKind::Missing,
-      {
+        Some(ModEntry { exported: false, .. }) if public => ErrKind::Private,
-        if require_exported && !dereference([exported]) {
+        Some(ModEntry { member: ModMember::Item(_), .. }) => ErrKind::NotModule,
-          return Err(WalkError { pos, kind: WalkErrorKind::Private });
+        Some(ModEntry { member: ModMember::Sub(next), .. }) => {
+          module = next;
+          continue;
+        },
+      };
+      let options = module.keys(public);
+      return Err(WalkError { kind, prefix, path, pos, options });
     }
-        cur = next
+    Ok(module)
+  }
+
+  /// Return the member at the end of the given path
+  ///
+  /// # Panics
+  ///
+  /// if path is empty, since the reference cannot be forwarded that way
+  #[allow(clippy::needless_arbitrary_self_type)] // duplicate
+  pub fn walk1_ref<'a: 'b, 'b>(
+    &'a self,
+    prefix: &'b [Tok<String>],
+    path: &'b [Tok<String>],
+    public: bool,
+  ) -> Result<(&'a ModEntry<TItem, TExt>, &'a Self), WalkError<'b>> {
+    let (last, parent) = path.split_last().expect("Path cannot be empty");
+    let pos = path.len() - 1;
+    let module = self.walk_ref(prefix, parent, public)?;
+    if let Some(entry) = &module.entries.get(last) {
+      if !entry.exported && public {
+        let options = module.keys(public);
+        Err(WalkError { kind: ErrKind::Private, options, prefix, path, pos })
       } else {
-        return Err(WalkError { pos, kind: WalkErrorKind::Missing });
+        Ok((entry, module))
       }
+    } else {
+      let options = module.keys(public);
+      Err(WalkError { kind: ErrKind::Missing, options, prefix, path, pos })
     }
-    Ok(cur)
   }
 
-  fn visit_all_imports_rec<E>(
+  fn search_all_rec<'a, T, E>(
-    &self,
+    &'a self,
     path: ModPath,
-    callback: &mut impl FnMut(ModPath, &Self, &Import) -> Result<(), E>,
+    mut state: T,
-  ) -> Result<(), E> {
+    callback: &mut impl FnMut(ModPath, &'a Self, T) -> Result<T, E>,
-    for import in self.imports.iter() {
+  ) -> Result<T, E> {
-      callback(path.clone(), self, import)?
+    state = callback(path.clone(), self, state)?;
-    }
+    for (name, entry) in &self.entries {
-    for (name, entry) in self.items.iter() {
       if let ModMember::Sub(module) = &entry.member {
-        module.visit_all_imports_rec(path.push(name.clone()), callback)?
+        state =
+          module.search_all_rec(path.push(name.clone()), state, callback)?;
       }
     }
-    Ok(())
+    Ok(state)
   }
 
-  /// Call the provided function on every import in the tree. Can be
+  /// Visit every element in the tree with the provided function
-  /// short-circuited by returning Err
+  ///
-  pub fn visit_all_imports<E>(
+  /// * init - can be used for reduce, otherwise pass `()`
-    &self,
+  /// * callback - a callback applied on every module. Can return [Err] to
-    callback: &mut impl FnMut(ModPath, &Self, &Import) -> Result<(), E>,
+  ///   short-circuit the walk
-  ) -> Result<(), E> {
+  ///   * [ModPath] - a substack indicating the path to the current module from
-    self.visit_all_imports_rec(Substack::Bottom, callback)
+  ///     wherever the walk begun
+  ///   * [Module] - the current module
+  ///   * T - data for reduce. If not used, destructure `()`
+  pub fn search_all<'a, T, E>(
+    &'a self,
+    init: T,
+    callback: &mut impl FnMut(ModPath, &'a Self, T) -> Result<T, E>,
+  ) -> Result<T, E> {
+    self.search_all_rec(Substack::Bottom, init, callback)
   }
 
   /// Combine two module trees; wherever they conflict, the overlay is
   /// preferred.
-  pub fn overlay(mut self, overlay: Self) -> Self
+  pub fn overlay<E>(mut self, overlay: Self) -> Result<Self, E>
   where
-    TExt: Add<TExt, Output = TExt>,
+    TExt: Add<TExt, Output = Result<TExt, E>>,
   {
-    let Module { extra, imports, items } = overlay;
+    let Module { extra, entries: items } = overlay;
     let mut new_items = HashMap::new();
     for (key, right) in items {
       // if both contain a submodule
-      match (self.items.remove(&key), right) {
+      match (self.entries.remove(&key), right) {
         (
           Some(ModEntry { member: ModMember::Sub(lsub), .. }),
           ModEntry { member: ModMember::Sub(rsub), exported },
         ) => new_items.insert(key, ModEntry {
           exported,
-          member: ModMember::Sub(lsub.overlay(rsub)),
+          member: ModMember::Sub(lsub.overlay(rsub)?),
         }),
         (_, right) => new_items.insert(key, right),
       };
     }
-    new_items.extend(self.items.into_iter());
+    new_items.extend(self.entries.into_iter());
-    self.imports.extend(imports.into_iter());
+    Ok(Module { entries: new_items, extra: (self.extra + extra)? })
-    Module {
-      items: new_items,
-      imports: self.imports,
-      extra: self.extra + extra,
   }
 }
+
+impl<TItem: Clone + Display, TExt: Clone + Display> Display
+  for Module<TItem, TExt>
+{
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    write!(f, "Module {{\nchildren:")?;
+    for (name, entry) in &self.entries {
+      match entry.exported {
+        true => write!(f, "\npublic {name} = "),
+        false => write!(f, "\n{name} = "),
+      }?;
+      match &entry.member {
+        ModMember::Sub(module) => write!(f, "{module}"),
+        ModMember::Item(item) => write!(f, "{item}"),
+      }?;
+    }
+    write!(f, "\nextra: {}\n}}", &self.extra)
+  }
+}
+
+/// Possible causes why the path could not be walked
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum ErrKind {
+  /// `require_exported` was set to `true` and a module wasn't exported
+  Private,
+  /// A module was not found
+  Missing,
+  /// The path leads into a leaf node
+  NotModule,
+}
+
+/// All details about a failed tree-walk
+pub struct WalkError<'a> {
+  /// Failure mode
+  pub kind: ErrKind,
+  /// Path to the module where the walk started
+  pub prefix: &'a [Tok<String>],
+  /// Planned walk path
+  pub path: &'a [Tok<String>],
+  /// Index into walked path where the error occurred
+  pub pos: usize,
+  /// Alternatives to the failed steps
+  pub options: BoxedIter<'a, Tok<String>>,
+}
+impl<'a> WalkError<'a> {
+  /// Total length of the path represented by this error
+  pub fn depth(&self) -> usize {
+    self.prefix.len() + self.pos + 1
+  }
+
+  /// Attach a location to the error and convert into trait object for reporting
+  pub fn at(self, location: &Location) -> Rc<dyn ProjectError> {
+    // panic!("hello");
+    WalkErrorWithLocation {
+      kind: self.kind,
+      location: location.clone(),
+      path: (self.prefix.iter())
+        .chain(self.path.iter().take(self.pos + 1))
+        .cloned()
+        .collect(),
+      options: self.options.collect(),
+    }
+    .rc()
+  }
+}
+
+/// Error produced by [WalkError::at]
+struct WalkErrorWithLocation {
+  path: VName,
+  kind: ErrKind,
+  options: VName,
+  location: Location,
+}
+impl ProjectError for WalkErrorWithLocation {
+  fn description(&self) -> &str {
+    match self.kind {
+      ErrKind::Missing => "Nonexistent path",
+      ErrKind::NotModule => "The path leads into a leaf",
+      ErrKind::Private => "The path leads into a private module",
+    }
+  }
+
+  fn message(&self) -> String {
+    let paths = Interner::extern_all(&self.path).join("::");
+    let options = Interner::extern_all(&self.options).join(", ");
+    match &self.kind {
+      ErrKind::Missing =>
+        format!("{paths} does not exist, options are {options}"),
+      ErrKind::NotModule =>
+        format!("{paths} is not a module, options are {options}"),
+      ErrKind::Private => format!("{paths} is private, options are {options}"),
+    }
+  }
+
+  fn one_position(&self) -> Location {
+    self.location.clone()
+  }
 }

src/rule/matcher_vectree/shared.rs

@@ -10,7 +10,7 @@ use crate::representations::Primitive;
 use crate::rule::matcher::{Matcher, RuleExpr};
 use crate::rule::state::State;
 use crate::utils::Side;
-use crate::Sym;
+use crate::{Sym, VName};
 
 pub enum ScalMatcher {
   P(Primitive),
@@ -47,7 +47,7 @@ pub enum VecMatcher {
     /// the length of matches on either side.
     ///
     /// Vectorial keys that appear on either side, in priority order
-    key_order: Vec<Tok<String>>,
+    key_order: VName,
   },
 }
 

src/systems/io/facade.rs

@@ -16,9 +16,9 @@ use crate::foreign::cps_box::CPSBox;
 use crate::foreign::{Atomic, ExternError};
 use crate::interpreter::HandlerTable;
 use crate::pipeline::file_loader::embed_to_map;
-use crate::sourcefile::{FileEntry, Import};
+use crate::sourcefile::{FileEntry, FileEntryKind, Import};
 use crate::systems::asynch::{Asynch, MessagePort};
-use crate::Interner;
+use crate::{Interner, Location};
 
 trait_set! {
   pub trait StreamTable = IntoIterator<Item = (&'static str, IOStream)>
@@ -144,10 +144,14 @@ impl<'a, P: MessagePort, ST: StreamTable + 'a> IntoSystem<'a>
       name: vec!["system".to_string(), "io".to_string()],
       constants: io_bindings(i, streams).unwrap_tree(),
       code: embed_to_map::<IOEmbed>(".orc", i),
-      prelude: vec![FileEntry::Import(vec![Import {
+      prelude: vec![FileEntry {
+        locations: vec![Location::Unknown],
+        kind: FileEntryKind::Import(vec![Import {
+          location: Location::Unknown,
           path: vec![i.i("system"), i.i("io"), i.i("prelude")],
           name: None,
-      }])],
+        }]),
+      }],
       handlers,
     }
   }

src/systems/stl/bool.orc

@@ -1,6 +1,8 @@
+export operators[ != == ]
+
 export const not := \bool. if bool then false else true
-export macro ...$a != ...$b =0x3p36=> (not (...$a == ...$b))
+macro ...$a != ...$b =0x3p36=> (not (...$a == ...$b))
-export macro ...$a == ...$b =0x3p36=> (equals (...$a) (...$b))
+macro ...$a == ...$b =0x3p36=> (equals (...$a) (...$b))
 export macro if ...$cond then ...$true else ...$false:1 =0x1p84=> (
   ifthenelse (...$cond) (...$true) (...$false)
 )

src/systems/stl/fn.orc

@@ -18,9 +18,11 @@ export const pass2 := \a.\b.\cont. cont a b
 ]--
 export const return := \a. \b.a
 
-export macro ...$prefix $ ...$suffix:1 =0x1p38=> ...$prefix (...$suffix)
+export operators[$ |> =>]
-export macro ...$prefix |> $fn ..$suffix:1 =0x2p32=> $fn (...$prefix) ..$suffix
 
-export macro ($name) => ...$body =0x2p129=> (\$name. ...$body)
+macro ...$prefix $ ...$suffix:1 =0x1p38=> ...$prefix (...$suffix)
-export macro ($name, ...$argv) => ...$body =0x2p129=> (\$name. (...$argv) => ...$body)
+macro ...$prefix |> $fn ..$suffix:1 =0x2p32=> $fn (...$prefix) ..$suffix
+
+macro ($name) => ...$body =0x2p129=> (\$name. ...$body)
+macro ($name, ...$argv) => ...$body =0x2p129=> (\$name. (...$argv) => ...$body)
 macro $name => ...$body =0x1p129=> (\$name. ...$body)

src/systems/stl/known.orc

@@ -1 +1,3 @@
-export ::[,]
+export operators[ , ]
+
+export const foo := \a.a

src/systems/stl/mod.rs

@@ -7,9 +7,9 @@ mod conv;
 mod inspect;
 mod num;
 mod panic;
+mod state;
 mod stl_system;
 mod str;
-mod state;
 pub use arithmetic_error::ArithmeticError;
 pub use bin::Binary;
 pub use num::Numeric;

src/systems/stl/num.orc

@@ -1,5 +1,7 @@
-export macro ...$a + ...$b =0x2p36=> (add (...$a) (...$b))
+export operators[ + - * % / ]
-export macro ...$a - ...$b:1 =0x2p36=> (subtract (...$a) (...$b))
+
-export macro ...$a * ...$b =0x1p36=> (multiply (...$a) (...$b))
+macro ...$a + ...$b =0x2p36=> (add (...$a) (...$b))
-export macro ...$a % ...$b:1 =0x1p36=> (remainder (...$a) (...$b))
+macro ...$a - ...$b:1 =0x2p36=> (subtract (...$a) (...$b))
-export macro ...$a / ...$b:1 =0x1p36=> (divide (...$a) (...$b))
+macro ...$a * ...$b =0x1p36=> (multiply (...$a) (...$b))
+macro ...$a % ...$b:1 =0x1p36=> (remainder (...$a) (...$b))
+macro ...$a / ...$b:1 =0x1p36=> (divide (...$a) (...$b))

src/systems/stl/proc.orc

@@ -1,5 +1,7 @@
 import super::fn::=>
 
+export operators[ ; = ]
+
 -- remove duplicate ;-s
 export macro do {
   ...$statement ; ; ...$rest:1
@@ -11,6 +13,8 @@ export macro do {
 } =0x2p130=> statement (...$statement) do { ...$rest }
 export macro do { ...$return } =0x1p130=> ...$return
 
+export ::do
+
 export macro statement (let $name = ...$value) ...$next =0x1p230=> (
   ( \$name. ...$next) (...$value)
 )

src/systems/stl/stl_system.rs

@@ -13,7 +13,8 @@ use super::str::str;
 use crate::facade::{IntoSystem, System};
 use crate::interner::Interner;
 use crate::pipeline::file_loader::embed_to_map;
-use crate::sourcefile::{FileEntry, Import};
+use crate::sourcefile::{FileEntry, FileEntryKind, Import};
+use crate::Location;
 
 /// Feature flags for the STL.
 #[derive(Default)]
@@ -29,8 +30,6 @@ pub struct StlConfig {
 #[include = "*.orc"]
 struct StlEmbed;
 
-// TODO: fix all orc modules to not rely on prelude
-
 impl IntoSystem<'static> for StlConfig {
   fn into_system(self, i: &Interner) -> System<'static> {
     let pure_fns =
@@ -41,10 +40,14 @@ impl IntoSystem<'static> for StlConfig {
       name: vec!["std".to_string()],
       constants: HashMap::from([(i.i("std"), fns)]),
       code: embed_to_map::<StlEmbed>(".orc", i),
-      prelude: vec![FileEntry::Import(vec![Import {
+      prelude: vec![FileEntry {
+        locations: vec![Location::Unknown],
+        kind: FileEntryKind::Import(vec![Import {
+          location: Location::Unknown,
           path: vec![i.i("std"), i.i("prelude")],
           name: None,
-      }])],
+        }]),
+      }],
       handlers: state_handlers(),
     }
   }

src/systems/stl/str.orc

@@ -1,5 +1,7 @@
 import super::(proc::*, bool::*, panic)
 
+export operators[++]
+
 export macro ...$a ++ ...$b =0x4p36=> (concat (...$a) (...$b))
 
 export const char_at := \s.\i. do{

src/utils/get_or_default.rs

@@ -0,0 +1,20 @@
+use std::hash::Hash;
+
+use hashbrown::HashMap;
+
+/// Return the given value from the map or default-initialize if it doesn't
+/// exist, then retunrn a mutable reference.
+pub fn get_or_default<'a, K: Eq + Hash + Clone, V: Default>(
+  map: &'a mut HashMap<K, V>,
+  k: &K,
+) -> &'a mut V {
+  get_or_make(map, k, || V::default())
+}
+
+pub fn get_or_make<'a, K: Eq + Hash + Clone, V>(
+  map: &'a mut HashMap<K, V>,
+  k: &K,
+  make: impl FnOnce() -> V,
+) -> &'a mut V {
+  map.raw_entry_mut().from_key(k).or_insert_with(|| (k.clone(), make())).1
+}

src/utils/mod.rs

@@ -1,8 +1,10 @@
 mod cache;
 mod delete_cell;
 mod event_poller;
+mod get_or_default;
 mod iter_find;
-mod pushed;
+pub mod never;
+pub mod pushed;
 mod rc_to_owned;
 mod replace_first;
 mod side;
@@ -14,7 +16,6 @@ pub mod thread_pool;
 mod unwrap_or;
 
 pub use cache::Cache;
-pub use pushed::pushed;
 pub use rc_to_owned::{map_rc, rc_to_owned};
 pub use replace_first::replace_first;
 pub use side::Side;
@@ -24,6 +25,7 @@ pub(crate) use unwrap_or::unwrap_or;
 pub mod iter;
 pub use delete_cell::DeleteCell;
 pub use event_poller::{PollEvent, Poller};
+pub use get_or_default::{get_or_default, get_or_make};
 pub use iter::BoxedIter;
 pub use iter_find::iter_find;
 pub use string_from_charset::string_from_charset;

src/utils/never.rs

@@ -0,0 +1,17 @@
+//! A stable implementation of the never and infallible results
+
+/// An enum with no values
+pub enum Never {}
+
+/// An infallible result
+pub type Always<T> = Result<T, Never>;
+
+/// Wrap value in a result with an impossible failure mode
+pub fn always<T>(t: T) -> Result<T, Never> {
+  Ok(t)
+}
+
+/// Take success value out of a result with an impossible failure mode
+pub fn unwrap_always<T>(result: Result<T, Never>) -> T {
+  result.unwrap_or_else(|_| unreachable!("Never has no values"))
+}

src/utils/pushed.rs

@@ -3,7 +3,18 @@ use std::iter;
 /// Pure version of [Vec::push]
 ///
 /// Create a new vector consisting of the provided vector with the
-/// element appended
+/// element appended. See [pushed_ref] to use it with a slice
-pub fn pushed<T: Clone>(vec: &[T], t: T) -> Vec<T> {
+pub fn pushed<T: Clone>(vec: impl IntoIterator<Item = T>, t: T) -> Vec<T> {
-  vec.iter().cloned().chain(iter::once(t)).collect()
+  vec.into_iter().chain(iter::once(t)).collect()
+}
+
+/// Pure version of [Vec::push]
+///
+/// Create a new vector consisting of the provided slice with the
+/// element appended. See [pushed] for the owned version
+pub fn pushed_ref<'a, T: Clone + 'a>(
+  vec: impl IntoIterator<Item = &'a T>,
+  t: T,
+) -> Vec<T> {
+  vec.into_iter().cloned().chain(iter::once(t)).collect()
 }

src/utils/split_max_prefix.rs

@@ -1,14 +1,10 @@
 /// Split off the longest prefix accepted by the validator
-#[allow(clippy::type_complexity)] // FIXME couldn't find a good factoring
 pub fn split_max_prefix<'a, T>(
   path: &'a [T],
   is_valid: &impl Fn(&[T]) -> bool,
 ) -> Option<(&'a [T], &'a [T])> {
-  for split in (0..=path.len()).rev() {
+  (0..=path.len())
-    let (filename, subpath) = path.split_at(split);
+    .rev()
-    if is_valid(filename) {
+    .map(|i| path.split_at(i))
-      return Some((filename, subpath));
+    .find(|(file, _)| is_valid(file))
-    }
-  }
-  None
 }

src/utils/substack.rs

@@ -44,12 +44,13 @@ impl<'a, T> Substack<'a, T> {
     Stackframe { item, prev: self, len: self.opt().map_or(1, |s| s.len + 1) }
   }
   /// obtain the previous stackframe if one exists
-  /// TODO: this should return a [Substack]
+  pub fn pop(&'a self, count: usize) -> &'a Substack<'a, T> {
-  pub fn pop(&'a self, count: usize) -> Option<&'a Stackframe<'a, T>> {
+    if count == 0 {
-    if let Self::Frame(p) = self {
+      self
-      if count == 0 { Some(p) } else { p.prev.pop(count - 1) }
+    } else if let Self::Frame(p) = self {
+      p.prev.pop(count - 1)
     } else {
-      None
+      &Substack::Bottom
     }
   }
   /// number of stackframes