Implement parsing of `toMap` keyword

9 files changed, 38 insertions, 10 deletions

diff --git a/dhall/build.rs b/dhall/build.rs
index 4c654c9..e31e39d 100644
--- a/dhall/build.rs
+++ b/dhall/build.rs
@@ -133,8 +133,6 @@ fn main() -> std::io::Result<()> {
                     || path == "unit/import/urls/emptyPath0"
                     || path == "unit/import/urls/emptyPath1"
                     || path == "unit/import/urls/emptyPathSegment"
-                    // TODO: toMap
-                    || path == "toMap"
             },
             input_type: FileType::Text,
             output_type: Some(FileType::Binary),
@@ -172,8 +170,6 @@ fn main() -> std::io::Result<()> {
                     || path == "unit/import/urls/emptyPath0"
                     || path == "unit/import/urls/emptyPath1"
                     || path == "unit/import/urls/emptyPathSegment"
-                    // TODO: toMap
-                    || path == "toMap"
             },
             input_type: FileType::Text,
             output_type: Some(FileType::Binary),
@@ -203,8 +199,6 @@ fn main() -> std::io::Result<()> {
                     || path == "unit/import/urls/emptyPath0"
                     || path == "unit/import/urls/emptyPath1"
                     || path == "unit/import/urls/emptyPathSegment"
-                    // TODO: toMap
-                    || path == "toMap"
             },
             input_type: FileType::Text,
             output_type: Some(FileType::Binary),
@@ -222,9 +216,6 @@ fn main() -> std::io::Result<()> {
                     // TODO: projection by expression
                     || path == "unit/RecordProjectFields"
                     || path == "unit/recordProjectionByExpression"
-                    // TODO: toMap
-                    || path == "unit/ToMap"
-                    || path == "unit/ToMapAnnotated"
             },
             input_type: FileType::Binary,
             output_type: Some(FileType::Text),
diff --git a/dhall/src/phase/binary.rs b/dhall/src/phase/binary.rs
index 7dc9be2..40219d9 100644
--- a/dhall/src/phase/binary.rs
+++ b/dhall/src/phase/binary.rs
@@ -366,6 +366,15 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<DecodedExpr, DecodeError> {
                 let y = cbor_value_to_dhall(&y)?;
                 Annot(x, y)
             }
+            [U64(27), x] => {
+                let x = cbor_value_to_dhall(&x)?;
+                ToMap(x, None)
+            }
+            [U64(27), x, y] => {
+                let x = cbor_value_to_dhall(&x)?;
+                let y = cbor_value_to_dhall(&y)?;
+                ToMap(x, Some(y))
+            }
             [U64(28), x] => {
                 let x = cbor_value_to_dhall(&x)?;
                 EmptyListLit(x)
@@ -550,6 +559,8 @@ where
         Merge(x, y, Some(z)) => {
             ser_seq!(ser; tag(6), expr(x), expr(y), expr(z))
         }
+        ToMap(x, None) => ser_seq!(ser; tag(27), expr(x)),
+        ToMap(x, Some(y)) => ser_seq!(ser; tag(27), expr(x), expr(y)),
         Projection(x, ls) => ser.collect_seq(
             once(tag(10))
                 .chain(once(expr(x)))
diff --git a/dhall/src/phase/normalize.rs b/dhall/src/phase/normalize.rs
index 82a378c..3f6e99c 100644
--- a/dhall/src/phase/normalize.rs
+++ b/dhall/src/phase/normalize.rs
@@ -765,6 +765,7 @@ pub(crate) fn normalize_one_layer(
                 }
             }
         }
+        ExprF::ToMap(_, _) => unimplemented!("toMap"),
     };
 
     match ret {
diff --git a/dhall/src/phase/typecheck.rs b/dhall/src/phase/typecheck.rs
index 52a4e47..9013c1f 100644
--- a/dhall/src/phase/typecheck.rs
+++ b/dhall/src/phase/typecheck.rs
@@ -757,6 +757,7 @@ fn type_last_layer(
                 (None, None) => return mkerr(MergeEmptyNeedsAnnotation),
             }
         }
+        ToMap(_, _) => unimplemented!("toMap"),
         Projection(record, labels) => {
             let record_type = record.get_type()?;
             let record_borrow = record_type.as_whnf();
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,
diff --git a/tests_buffer b/tests_buffer
index 67de9eb..446c3f0 100644
--- a/tests_buffer
+++ b/tests_buffer
@@ -10,6 +10,8 @@ success/
     LetNoAnnot let x = y in e
     LetAnnot let x: T = y in e
     EmptyRecordLiteral {=}
+    ToMap toMap x
+    ToMapAnnot toMap x : T
 failure/
     AssertNoAnnotation assert