From 0a471ed71c32f58a2d5f56ccca65d256044c741a Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Mon, 22 Nov 2021 01:59:05 -0800
Subject: [PATCH] For expression stuff

---
 schala-lang/src/ast/mod.rs            |  3 ++-
 schala-lang/src/parsing/combinator.rs |  5 +++--
 schala-lang/src/parsing/peg_parser.rs |  4 ++--
 schala-lang/src/parsing/test.rs       | 12 ++++++++++--
 4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/schala-lang/src/ast/mod.rs b/schala-lang/src/ast/mod.rs
index 6500ae5..eb85983 100644
--- a/schala-lang/src/ast/mod.rs
+++ b/schala-lang/src/ast/mod.rs
@@ -267,8 +267,9 @@ pub enum PatternLiteral {
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct Enumerator {
-    pub id: Rc<String>, //TODO rename this field
+    pub identifier: Rc<String>,
     pub generator: Expression,
+    pub assignment: bool, //true if `=`, false if `<-`
 }
 
 #[derive(Debug, PartialEq, Clone)]
diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index 5e14998..68d3ec0 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -791,12 +791,13 @@ fn for_expr(input: Span) -> ParseResult<ExpressionKind> {
     fn enumerator(input: Span) -> ParseResult<Enumerator> {
         alt((
             map(separated_pair(identifier, kw("<-"), expression_no_struct), |(ident, generator)| {
-                Enumerator { id: rc_string(ident.fragment()), generator }
+                Enumerator { identifier: rc_string(ident.fragment()), generator, assignment: false }
             }),
             //TODO distinguish these two cases in AST
             map(separated_pair(identifier, kw("="), expression_no_struct), |(ident, generator)| Enumerator {
-                id: rc_string(ident.fragment()),
+                identifier: rc_string(ident.fragment()),
                 generator,
+                assignment: true,
             }),
         ))(input)
     }
diff --git a/schala-lang/src/parsing/peg_parser.rs b/schala-lang/src/parsing/peg_parser.rs
index e81b3dc..9a6c034 100644
--- a/schala-lang/src/parsing/peg_parser.rs
+++ b/schala-lang/src/parsing/peg_parser.rs
@@ -298,11 +298,11 @@ peg::parser! {
         //TODO add guards, etc.
         rule enumerator(parser: &mut Parser) -> Enumerator =
             ident:identifier() _ "<-" _ generator:expression_no_struct(parser) {
-                Enumerator { id: Rc::new(ident.to_string()), generator }
+                Enumerator { identifier: Rc::new(ident.to_string()), generator, assignment: false }
             } /
             //TODO need to distinguish these two cases in AST
             ident:identifier() _ "=" _ generator:expression_no_struct(parser) {
-                Enumerator { id: Rc::new(ident.to_string()), generator }
+                Enumerator { identifier: Rc::new(ident.to_string()), generator, assignment: true }
             }
 
         rule for_body(parser: &mut Parser) -> Box<ForBody> =
diff --git a/schala-lang/src/parsing/test.rs b/schala-lang/src/parsing/test.rs
index e23078f..6765a24 100644
--- a/schala-lang/src/parsing/test.rs
+++ b/schala-lang/src/parsing/test.rs
@@ -405,7 +405,11 @@ fn for_expression() {
     assert_expr!(
         "for { a <- garodzny::maybeValue } return 1",
         expr(ForExpression {
-            enumerators: vec![Enumerator { id: rc("a"), generator: expr(Value(qn!(garodzny, maybeValue))) }],
+            enumerators: vec![Enumerator {
+                identifier: rc("a"),
+                assignment: false,
+                generator: expr(Value(qn!(garodzny, maybeValue)))
+            }],
             body: bx(ForBody::MonadicReturn(expr(NatLiteral(1))))
         })
     );
@@ -413,7 +417,11 @@ fn for_expression() {
     assert_expr!(
         "for n <- someRange { f(n) ; }",
         expr(ForExpression {
-            enumerators: vec![Enumerator { id: rc("n"), generator: expr(Value(qn!(someRange))) }],
+            enumerators: vec![Enumerator {
+                identifier: rc("n"),
+                assignment: false,
+                generator: expr(Value(qn!(someRange)))
+            }],
             body: bx(ForBody::StatementBlock(
                 vec![stmt(StatementKind::Expression(expr(Call {
                     f: bx(expr(Value(qn!(f)))),