Starting for expr

schala-lang/language/src/parser.rs

@@ -149,12 +149,41 @@ fn primary_expr(text: &str) -> ParseResult<ExpressionKind> {
 
   alt((
     if_expr,
+    for_expr,
     literal,
     paren_expr,
     identifier_expr,
   ))(text)
 }
 
+fn for_expr(text: &str) -> ParseResult<ExpressionKind> {
+  //TODO do I need something like no struct literal here?
+  let en = alt((
+    map(enumerator, |e| vec![e]),
+    delimited(tag("{"), enumerators, tag("}"))
+  ));
+  preceded(tag("for"),
+    map(tuple((en, for_expr_body)),
+    |(enumerators, body)| ExpressionKind::ForExpression { enumerators, body: Box::new(body) }
+  ))(text)
+}
+
+fn enumerators(text: &str) -> ParseResult<Vec<Enumerator>> {
+  separated_nonempty_list(alt((value((), tag(",")), statement_sep)),
+    enumerator)(text)
+}
+
+fn enumerator(text: &str) -> ParseResult<Enumerator> {
+  map(
+    tuple((identifier, tag("<-"), expression)),
+  |(id, _, generator)| Enumerator { id, generator }
+  )(text)
+}
+
+fn for_expr_body(text: &str) -> ParseResult<ForBody> {
+  unimplemented!()
+}
+
 fn invocation_argument(text: &str) -> ParseResult<InvocationArgument> {
   use nom::character::complete::char;
   alt((