From d5cd0dada79ce7e6ca14e9ac4cd0dd3b5ba4ecfb Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Thu, 18 Nov 2021 18:58:46 -0800
Subject: [PATCH] Impl, interface

---
 schala-lang/src/parsing/combinator.rs | 63 +++++++++++++++++++++++++--
 schala-lang/src/parsing/test.rs       | 10 ++---
 2 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index 0720d44..28ffae8 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -105,14 +105,16 @@ pub fn block(input: Span) -> ParseResult<Block> {
     context(
         "block",
         map(
-            tuple((
+            delimited(
                 tok(char('{')),
+                tuple((
                 many0(statement_delimiter),
                 separated_list0(statement_delimiter, statement),
                 many0(statement_delimiter),
+                )),
                 tok(char('}')),
-            )),
-            |(_, _, items, _, _)| items.into(),
+            ),
+            |(_, items, _)| items.into(),
         ),
     )(input)
 }
@@ -129,7 +131,60 @@ fn statement(input: Span) -> ParseResult<Statement> {
 }
 
 fn declaration(input: Span) -> ParseResult<Declaration> {
-    alt((binding, type_decl, func, annotation, module))(input)
+    alt((binding, type_decl, func, annotation, module, interface, implementation))(input)
+}
+
+fn implementation(input: Span) -> ParseResult<Declaration> {
+    alt((
+        map(
+            preceded(kw("impl"), tuple((type_singleton_name, kw("for"), type_identifier, decl_block))),
+            |(if_name, _, type_name, block)| Declaration::Impl {
+                type_name,
+                interface_name: Some(if_name),
+                block,
+            },
+        ),
+        map(preceded(kw("impl"), pair(type_identifier, decl_block)), |(type_name, block)| {
+            Declaration::Impl { type_name, interface_name: None, block }
+        }),
+    ))(input)
+}
+
+fn decl_block(input: Span) -> ParseResult<Vec<Declaration>> {
+    delimited(
+        tok(char('{')),
+        map(
+            tuple((
+                many0(statement_delimiter),
+                separated_list0(statement_delimiter, func_decl),
+                many0(statement_delimiter),
+            )),
+            |(_, signatures, _)| signatures,
+        ),
+        tok(char('}')),
+    )(input)
+}
+
+fn interface(input: Span) -> ParseResult<Declaration> {
+    map(preceded(kw("interface"), pair(tok(identifier), signature_block)), |(name, signatures)| {
+        Declaration::Interface { name: rc_string(name.fragment()), signatures }
+    })(input)
+}
+
+//TODO make the blocks parameterizable
+fn signature_block(input: Span) -> ParseResult<Vec<Signature>> {
+    delimited(
+        tok(char('{')),
+        map(
+            tuple((
+                many0(statement_delimiter),
+                separated_list0(statement_delimiter, func_signature),
+                many0(statement_delimiter),
+            )),
+            |(_, signatures, _)| signatures,
+        ),
+        tok(char('}')),
+    )(input)
 }
 
 fn annotation(input: Span) -> ParseResult<Declaration> {
diff --git a/schala-lang/src/parsing/test.rs b/schala-lang/src/parsing/test.rs
index 1059bd3..84ce6a2 100644
--- a/schala-lang/src/parsing/test.rs
+++ b/schala-lang/src/parsing/test.rs
@@ -921,7 +921,7 @@ fn functions_with_default_args() {
 #[test]
 fn interface() {
     let glue = TypeIdentifier::Singleton(TypeSingletonName { name: rc("Glue"), params: vec![] });
-    assert_ast!(
+    assert_ast_comb!(
         "interface Unglueable { fn unglue(a: Glue); fn mar(): Glue }",
         vec![decl(Declaration::Interface {
             name: rc("Unglueable"),
@@ -953,13 +953,13 @@ fn impls() {
         ),
     ];
 
-    assert_ast!(
+    assert_ast_comb!(
         "impl Heh { fn yolo() { }; fn swagg() { } }",
         vec![decl(Impl { type_name: ty_simple("Heh"), interface_name: None, block: block.clone() })]
     );
 
     //TODO `"impl Heh<X> { fn yolo() { }; fn swagg() { }; }"` ought to work
-    assert_ast!(
+    assert_ast_comb!(
         "impl Heh<X> { fn yolo() { }; fn swagg() { } }",
         vec![decl(Impl {
             type_name: TypeIdentifier::Singleton(TypeSingletonName {
@@ -971,7 +971,7 @@ fn impls() {
         })]
     );
 
-    assert_ast!(
+    assert_ast_comb!(
         "impl Heh for Saraz { fn yolo() {}; fn swagg() {} }",
         vec![decl(Impl {
             type_name: ty_simple("Saraz"),
@@ -980,7 +980,7 @@ fn impls() {
         })]
     );
 
-    assert_ast!(
+    assert_ast_comb!(
         "impl Heh<T> for (Int, Codepoint) {}",
         vec![decl(Impl {
             type_name: TypeIdentifier::Tuple(vec![ty_simple("Int"), ty_simple("Codepoint")]),