Implement parsing of `toMap` keyword

4 files changed, 23 insertions, 1 deletions

diff --git a/dhall_syntax/src/core/expr.rs b/dhall_syntax/src/core/expr.rs
index 2d73a64..51b6c47 100644
--- a/dhall_syntax/src/core/expr.rs
+++ b/dhall_syntax/src/core/expr.rs
@@ -243,6 +243,8 @@ pub enum ExprF<SubExpr, Embed> {
     UnionType(DupTreeMap<Label, Option<SubExpr>>),
     ///  `merge x y : t`
     Merge(SubExpr, SubExpr, Option<SubExpr>),
+    ///  `toMap x : t`
+    ToMap(SubExpr, Option<SubExpr>),
     ///  `e.x`
     Field(SubExpr, Label),
     ///  `e.{ x, y, z }`
diff --git a/dhall_syntax/src/core/visitor.rs b/dhall_syntax/src/core/visitor.rs
index 49fff60..435771e 100644
--- a/dhall_syntax/src/core/visitor.rs
+++ b/dhall_syntax/src/core/visitor.rs
@@ -150,6 +150,9 @@ where
                 v.visit_subexpr(y)?,
                 opt(t, |e| v.visit_subexpr(e))?,
             ),
+            ToMap(x, t) => {
+                ToMap(v.visit_subexpr(x)?, opt(t, |e| v.visit_subexpr(e))?)
+            }
             Field(e, l) => Field(v.visit_subexpr(e)?, l.clone()),
             Projection(e, ls) => Projection(v.visit_subexpr(e)?, ls.clone()),
             Assert(e) => Assert(v.visit_subexpr(e)?),
diff --git a/dhall_syntax/src/parser.rs b/dhall_syntax/src/parser.rs
index defa79b..24ecc1e 100644
--- a/dhall_syntax/src/parser.rs
+++ b/dhall_syntax/src/parser.rs
@@ -827,6 +827,7 @@ make_parser! {
     rule!(assert<()>);
     rule!(if_<()>);
     rule!(in_<()>);
+    rule!(toMap<()>);
 
     rule!(empty_list_literal<ParsedExpr>; span; children!(
         [application_expression(e)] => {
@@ -863,6 +864,9 @@ make_parser! {
         [assert(()), expression(x)] => {
             spanned(span, Assert(x))
         },
+        [toMap(()), import_expression(x), application_expression(y)] => {
+            spanned(span, ToMap(x, Some(y)))
+        },
         [operator_expression(e)] => e,
         [operator_expression(e), expression(annot)] => {
             spanned(span, Annot(e, annot))
@@ -934,7 +938,6 @@ make_parser! {
     ));
 
     rule!(Some_<()>);
-    rule!(toMap<()>);
 
     rule!(application_expression<ParsedExpr>; children!(
         [first_application_expression(e)] => e,
@@ -951,6 +954,9 @@ make_parser! {
         [merge(()), import_expression(x), import_expression(y)] => {
             spanned(span, Merge(x, y, None))
         },
+        [toMap(()), import_expression(x)] => {
+            spanned(span, ToMap(x, None))
+        },
         [import_expression(e)] => e,
     ));
 
diff --git a/dhall_syntax/src/printer.rs b/dhall_syntax/src/printer.rs
index 276590e..8571d11 100644
--- a/dhall_syntax/src/printer.rs
+++ b/dhall_syntax/src/printer.rs
@@ -41,6 +41,12 @@ impl<SE: Display + Clone, E: Display> Display for ExprF<SE, E> {
                     write!(f, " : {}", c)?;
                 }
             }
+            ToMap(a, b) => {
+                write!(f, "toMap {}", a)?;
+                if let Some(b) = b {
+                    write!(f, " : {}", b)?;
+                }
+            }
             Annot(a, b) => {
                 write!(f, "{} : {}", a, b)?;
             }
@@ -144,6 +150,7 @@ impl<A: Display + Clone> RawExpr<A> {
             | NEListLit(_)
             | SomeLit(_)
             | Merge(_, _, _)
+            | ToMap(_, _)
             | Annot(_, _)
                 if phase > Base =>
             {
@@ -172,6 +179,10 @@ impl<A: Display + Clone> RawExpr<A> {
                 b.phase(PrintPhase::Import),
                 c.map(|x| x.phase(PrintPhase::App)),
             ),
+            ToMap(a, b) => ToMap(
+                a.phase(PrintPhase::Import),
+                b.map(|x| x.phase(PrintPhase::App)),
+            ),
             Annot(a, b) => Annot(a.phase(Operator), b),
             ExprF::BinOp(op, a, b) => ExprF::BinOp(
                 op,