From 00a9ac7cf735b6dd55696e26088cc8b619bd26e9 Mon Sep 17 00:00:00 2001
From: Alex Bethel <abethel@cs.nmt.edu>
Date: Sun, 7 Aug 2022 13:03:09 -0500
Subject: [PATCH] Record types

---
 axc/src/parser.rs | 44 ++++++++++++++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/axc/src/parser.rs b/axc/src/parser.rs
index 0b8dbc9..c007beb 100644
--- a/axc/src/parser.rs
+++ b/axc/src/parser.rs
@@ -485,18 +485,22 @@ fn parse_literal(_m: &ParserMeta) -> impl Parser<char, Expr, Error = Simple<char
 
 fn parse_type(m: &ParserMeta) -> impl Parser<char, Type, Error = Simple<char>> {
     recursive(|rec| {
-        choice((parse_named_type(m), parse_tuple_type(m, rec)))
-            .repeated()
-            .at_least(1)
-            .map(|types| {
-                types
-                    .into_iter()
-                    .reduce(|l, r| Type::Application {
-                        function: Box::new(l),
-                        expression: Box::new(r),
-                    })
-                    .unwrap()
-            })
+        choice((
+            parse_named_type(m),
+            parse_tuple_type(m, rec.clone()),
+            parse_record_type(m, rec.clone()),
+        ))
+        .repeated()
+        .at_least(1)
+        .map(|types| {
+            types
+                .into_iter()
+                .reduce(|l, r| Type::Application {
+                    function: Box::new(l),
+                    expression: Box::new(r),
+                })
+                .unwrap()
+        })
     })
 }
 
@@ -513,6 +517,7 @@ fn parse_tuple_type(
         .delimited_by(just('(').then(whitespace()), just(')').then(whitespace()))
         .map(|types| {
             if types.len() == 1 {
+                // `(Int)` is the same as `Int`
                 types.into_iter().next().unwrap()
             } else {
                 Type::Tuple(types)
@@ -520,6 +525,21 @@ fn parse_tuple_type(
         })
 }
 
+fn parse_record_type(
+    _m: &ParserMeta,
+    rec: impl Parser<char, Type, Error = Simple<char>>,
+) -> impl Parser<char, Type, Error = Simple<char>> {
+    ident()
+        .then_ignore(whitespace())
+        .then_ignore(just(':'))
+        .then_ignore(whitespace())
+        .then(rec)
+        .separated_by(just(',').then(whitespace()))
+        .allow_trailing()
+        .delimited_by(just('{').then(whitespace()), just('}').then(whitespace()))
+        .map(Type::Record)
+}
+
 fn parse_pattern(m: &ParserMeta) -> impl Parser<char, Pattern, Error = Simple<char>> {
     // TODO: add all the patterns
     choice((parse_capture_pattern(m),))