Macro processing factored into Orchid functions

orchid-base/src/macros.rs

@@ -1,15 +1,18 @@
+use std::marker::PhantomData;
+use std::sync::Arc;
+
 use itertools::Itertools;
 use never::Never;
 use trait_set::trait_set;
 
-use crate::{match_mapping, name::Sym, tree::{Paren, Ph}};
-use std::{marker::PhantomData, sync::Arc};
-
-use crate::{api, location::Pos};
+use crate::location::Pos;
+use crate::name::Sym;
+use crate::tree::{Paren, Ph};
+use crate::{api, match_mapping};
 
 #[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct MacroSlot<'a>(api::MacroTreeId, PhantomData<&'a ()>);
-impl<'a> MacroSlot<'a> {
+impl MacroSlot<'_> {
   pub fn id(self) -> api::MacroTreeId { self.0 }
 }
 
@@ -21,7 +24,7 @@ trait_set! {
 #[derive(Clone, Debug)]
 pub struct MTree<'a, A> {
   pub pos: Pos,
-  pub tok: Arc<MTok<'a, A>>
+  pub tok: Arc<MTok<'a, A>>,
 }
 impl<'a, A> MTree<'a, A> {
   pub(crate) fn from_api(api: &api::MacroTree, do_atom: &mut impl MacroAtomFromApi<'a, A>) -> Self {
@@ -40,12 +43,16 @@ pub enum MTok<'a, A> {
   Lambda(Vec<MTree<'a, A>>, Vec<MTree<'a, A>>),
   Ph(Ph),
   Atom(A),
-  Ref(Box<MTok<'a, Never>>),
+  /// Used in extensions to directly return input
+  Ref(Arc<MTok<'a, Never>>),
+  /// Used in the matcher to skip previous macro output which can only go in
+  /// vectorial placeholders
+  Done(Arc<MTok<'a, A>>),
 }
 impl<'a, A> MTok<'a, A> {
   pub(crate) fn from_api(
     api: &api::MacroToken,
-    do_atom: &mut impl MacroAtomFromApi<'a, A>
+    do_atom: &mut impl MacroAtomFromApi<'a, A>,
   ) -> Self {
     match_mapping!(&api, api::MacroToken => MTok::<'a, A> {
       Lambda(x => mtreev_from_api(x, do_atom), b => mtreev_from_api(b, do_atom)),
@@ -58,6 +65,7 @@ impl<'a, A> MTok<'a, A> {
     })
   }
   pub(crate) fn to_api(&self, do_atom: &mut impl MacroAtomToApi<A>) -> api::MacroToken {
+    fn sink(n: &Never) -> api::MacroToken { match *n {} }
     match_mapping!(&self, MTok => api::MacroToken {
       Lambda(x => mtreev_to_api(x, do_atom), b => mtreev_to_api(b, do_atom)),
       Name(t.tok().to_api()),
@@ -65,22 +73,24 @@ impl<'a, A> MTok<'a, A> {
       S(p.clone(), b => mtreev_to_api(b, do_atom)),
       Slot(tk.0.clone()),
     } {
-      MTok::Ref(r) => r.to_api(&mut |e| match *e {}),
+      MTok::Ref(r) => r.to_api(&mut sink),
+      MTok::Done(t) => t.to_api(do_atom),
       MTok::Atom(a) => do_atom(a),
     })
   }
+  pub fn at(self, pos: Pos) -> MTree<'a, A> { MTree { pos, tok: Arc::new(self) } }
 }
 
 pub fn mtreev_from_api<'a, 'b, A>(
   api: impl IntoIterator<Item = &'b api::MacroTree>,
-  do_atom: &mut impl MacroAtomFromApi<'a, A>
+  do_atom: &mut impl MacroAtomFromApi<'a, A>,
 ) -> Vec<MTree<'a, A>> {
   api.into_iter().map(|api| MTree::from_api(api, do_atom)).collect_vec()
 }
 
 pub fn mtreev_to_api<'a: 'b, 'b, A: 'b>(
   v: impl IntoIterator<Item = &'b MTree<'a, A>>,
-  do_atom: &mut impl MacroAtomToApi<A>
+  do_atom: &mut impl MacroAtomToApi<A>,
 ) -> Vec<api::MacroTree> {
   v.into_iter().map(|t| t.to_api(do_atom)).collect_vec()
-}
+}