From 88d2571401df0b2fcad305c8b38c345b0ba1735b Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Fri, 19 Nov 2021 00:52:00 -0800
Subject: [PATCH] Lambdas

---
 schala-lang/src/parsing/combinator.rs | 11 ++++++++++-
 schala-lang/src/parsing/test.rs       | 14 +++++++-------
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index 2b00366..c8deb5a 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -454,13 +454,13 @@ fn primary_expr(allow_struct: bool) -> impl FnMut(Span) -> ParseResult<Expressio
 }
 
 fn primary_expr_no_struct(input: Span) -> ParseResult<ExpressionKind> {
-    println!("PRIM EXPR: {}", input.fragment());
     context(
         "primary-expr-no-struct",
         alt((
             while_expr,
             for_expr,
             if_expr,
+            lambda_expr,
             list_expr,
             paren_expr,
             string_literal,
@@ -487,6 +487,15 @@ fn record_block(input: Span) -> ParseResult<Vec<(Rc<String>, Expression)>> {
     delimited(tok(char('{')), separated_list0(tok(char(',')), record_entry), tok(char('}')))(input)
 }
 
+fn lambda_expr(input: Span) -> ParseResult<ExpressionKind> {
+    alt((
+        map(preceded(tok(char('\\')), tuple((formal_params, opt(type_anno), block))),
+        |(params, type_anno, body)| ExpressionKind::Lambda { params, type_anno, body }),
+        map(preceded(tok(char('\\')), tuple((formal_param, opt(type_anno), block))),
+        |(param, type_anno, body)| ExpressionKind::Lambda { params: vec![param], type_anno, body }),
+    ))(input)
+}
+
 fn while_expr(input: Span) -> ParseResult<ExpressionKind> {
     let id = fresh_id(&input);
     map(preceded(kw("while"), pair(opt(expression_no_struct), block)), move |(condition, body)| {
diff --git a/schala-lang/src/parsing/test.rs b/schala-lang/src/parsing/test.rs
index 71739c1..76519ca 100644
--- a/schala-lang/src/parsing/test.rs
+++ b/schala-lang/src/parsing/test.rs
@@ -416,7 +416,7 @@ fn for_expression() {
 fn lambda_expressions() {
     use ExpressionKind::*;
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\(x) { x + 1}"#,
         expr(Lambda {
             params: vec![FormalParam { name: rc!(x), anno: None, default: None }],
@@ -427,7 +427,7 @@ fn lambda_expressions() {
         })
     );
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\  (x: Int, y) { a;b;c;}"#,
         expr(Lambda {
             params: vec![
@@ -444,7 +444,7 @@ fn lambda_expressions() {
         })
     );
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\(x){y}(1)"#,
         expr(Call {
             f: bx(expr(Lambda {
@@ -456,7 +456,7 @@ fn lambda_expressions() {
         })
     );
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\(x: Int): String { "q" }"#,
         expr(Lambda {
             params: vec![FormalParam { name: rc!(x), anno: Some(ty_simple("Int")), default: None },],
@@ -473,7 +473,7 @@ fn lambda_expressions() {
 fn single_param_lambda() {
     use ExpressionKind::*;
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\x { x + 10 }"#,
         expr(Lambda {
             params: vec![FormalParam { name: rc!(x), anno: None, default: None },],
@@ -487,7 +487,7 @@ fn single_param_lambda() {
         })
     );
 
-    assert_expr!(
+    assert_expr_comb!(
         r#"\x: Int { x + 10 }"#,
         expr(Lambda {
             params: vec![FormalParam { name: rc!(x), anno: Some(ty_simple("Int")), default: None },],
@@ -507,7 +507,7 @@ fn complex_lambdas() {
     use ExpressionKind::*;
 
     //TODO support this without the semicolon after the lambda
-    assert_ast! {
+    assert_ast_comb! {
     r#"fn wahoo() { let a = 10; \(x) { x + a }; }
     wahoo()(3) "#,
     vec![