Added directfs

Added a very rudimentary file I/O system suitable for experimenting
with the language further. A better one will be designed when we have
sensible error management.

src/pipeline/dealias/alias_cache.rs

@@ -1,59 +0,0 @@
-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

@@ -1,4 +1,3 @@
-// mod alias_cache;
 mod resolve_aliases;
 mod walk_with_links;
 

src/pipeline/dealias/resolve_aliases.rs

@@ -11,6 +11,7 @@ use crate::tree::{ModEntry, ModMember, Module};
 use crate::utils::pure_push::pushed;
 use crate::{Interner, ProjectTree, Tok, VName};
 
+#[must_use]
 fn resolve_aliases_rec(
   root: &ProjectMod<VName>,
   module: &ProjectMod<VName>,
@@ -26,7 +27,6 @@ fn resolve_aliases_rec(
         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() {
@@ -87,6 +87,7 @@ fn resolve_aliases_rec(
   }
 }
 
+#[must_use]
 pub fn resolve_aliases(
   project: ProjectTree<VName>,
   updated: &impl Fn(&[Tok<String>]) -> bool,

src/pipeline/dealias/walk_with_links.rs

@@ -12,6 +12,7 @@ pub enum Target<'a, N: NameLike> {
   Leaf(&'a ProjectItem<N>),
 }
 
+#[must_use = "this is the sole product of this function"]
 pub struct WalkReport<'a, N: NameLike> {
   pub target: Target<'a, N>,
   pub abs_path: VName,