Switch TableLit and Program to BoundedSeparated

src/desugar/basic.rs

@@ -1,4 +1,4 @@
-use crate::ast::Separated;
+use crate::ast::{BoundedSeparated, Separated};
 
 impl<E, S1, S2> Separated<E, S1, S2> {
     pub fn desugar_elem(self, desugar_elem: impl Fn(E) -> (E, bool)) -> (Self, bool) {
@@ -34,3 +34,26 @@ impl<E, S1, S2> Separated<E, S1, S2> {
         }
     }
 }
+
+impl<E> BoundedSeparated<E> {
+    pub fn desugar(self, desugar_elem: impl Fn(E) -> (E, bool)) -> (Self, bool) {
+        let mut desugared = false;
+        let mut elems = vec![];
+        for (s0, elem, s1) in self.elems {
+            if desugared {
+                elems.push((s0, elem, s1));
+            } else {
+                let (elem, elem_desugared) = desugar_elem(elem);
+                desugared = desugared || elem_desugared;
+                elems.push((s0, elem, s1));
+            }
+        }
+
+        let new = Self {
+            elems,
+            trailing: self.trailing,
+            span: self.span,
+        };
+        (new, desugared)
+    }
+}

src/desugar/call.rs

@@ -1,4 +1,4 @@
-use crate::ast::{Call, Expr, Ident, Lit, Separated, Space, TableLit, TableLitElem};
+use crate::ast::{BoundedSeparated, Call, Expr, Ident, Lit, Space, TableLit, TableLitElem};
 
 // TODO Add span for just the parentheses to ast, or limit span to parentheses
 
@@ -29,18 +29,15 @@ impl Call {
                     value: arg,
                     span,
                 };
-                let elems = Separated::NonEmpty {
-                    first_elem: call,
-                    last_elems: vec![((Space::empty(span), Space::empty(span)), arg)],
+                let elems = vec![
+                    (s0, call, Space::empty(span)),
+                    (Space::empty(span), arg, s2),
+                ];
+                let new = Expr::Lit(Lit::Table(TableLit(BoundedSeparated {
+                    elems,
                     trailing: None,
                     span,
-                };
-                let new = Expr::Lit(Lit::Table(TableLit {
-                    s0,
-                    elems,
-                    s1: s2,
-                    span,
-                }));
+                })));
                 (new, true)
             }
 

src/desugar/lit.rs

@@ -31,21 +31,8 @@ impl TableLitElem {
 
 impl TableLit {
     pub fn desugar(self) -> (Self, bool) {
-        let Self {
-            s0,
-            elems,
-            s1,
-            span,
-        } = self;
-
-        let (elems, desugared) = elems.desugar_elem(|e| e.desugar());
-        let new = Self {
-            s0,
-            elems,
-            s1,
-            span,
-        };
-        (new, desugared)
+        let (elems, desugared) = self.0.desugar(|e| e.desugar());
+        (Self(elems), desugared)
     }
 }
 

src/desugar/program.rs

@@ -9,24 +9,12 @@ impl Program {
                 (new, desugared)
             }
 
-            Self::Module {
-                s0,
-                s1,
-                elems,
-                s2,
-                span,
-            } => {
-                // `s0 module s1 elems s2`
-                // -> `s0 '{ s1 elems s2 } empty`
-                let table = TableLit {
-                    s0: s1,
-                    elems,
-                    s1: s2,
-                    span,
-                };
+            Self::Module { s0, elems, span } => {
+                // `s0 module elems`
+                // -> `s0 table`
                 let new = Self::Expr {
                     s0,
-                    expr: Expr::Lit(Lit::Table(table)),
+                    expr: Expr::Lit(Lit::Table(TableLit(elems))),
                     s1: Space::empty(span),
                     span,
                 };