rebel-parse: ast: typ: allow to distinguish between free and dynamic array length

2 files changed, 21 insertions, 6 deletions

diff --git a/crates/rebel-parse/src/ast/typ.rs b/crates/rebel-parse/src/ast/typ.rs
index 37aa33e..18ea827 100644
--- a/crates/rebel-parse/src/ast/typ.rs
+++ b/crates/rebel-parse/src/ast/typ.rs
@@ -11,10 +11,17 @@ pub enum Type<'a> {
 pub enum Literal<'a> {
 	Unit,
 	Tuple(Vec<Type<'a>>),
-	Array(Box<Type<'a>>, Option<u32>),
+	Array(Box<Type<'a>>, ArrayLen),
 	Struct(Vec<StructField<'a>>),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum ArrayLen {
+	Free,
+	Fixed(u32),
+	Dynamic,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct StructField<'a> {
 	pub name: &'a str,
diff --git a/crates/rebel-parse/src/grammar/recipe.rs b/crates/rebel-parse/src/grammar/recipe.rs
index 893d4b7..73ddb2e 100644
--- a/crates/rebel-parse/src/grammar/recipe.rs
+++ b/crates/rebel-parse/src/grammar/recipe.rs
@@ -66,16 +66,24 @@ peg::parser! {
 			/ p('(') elements:(typ() ** p(',')) p(',')? p(')') {
 				typ::Literal::Tuple(elements)
 			}
-			/ p('[') typ:typ() len:tagged(<p(';')>, <number()>)? p(']') { ?
-				let len = len
-					.map(|n| u32::try_from(n).or(Err("Invalid array length")))
-					.transpose()?;
-				Ok(typ::Literal::Array(Box::new(typ), len))
+			/ p('[') typ:typ() len:array_len() p(']') {
+				typ::Literal::Array(Box::new(typ), len)
 			}
 			/ p('{') entries:delimited(<struct_field_typ()>, <p(',')>) p('}') {
 				typ::Literal::Struct(entries)
 			}
 
+		rule array_len() -> typ::ArrayLen
+			= p(';') len:number() { ?
+				Ok(typ::ArrayLen::Fixed(len.try_into().or(Err("Invalid array length"))?))
+			}
+			/ p(';') [Token::Ident(name) if *name == "_"] {
+				typ::ArrayLen::Free
+			}
+			/ {
+				typ::ArrayLen::Dynamic
+			}
+
 		rule pat() -> Pat<'a>
 			= path:path() { Pat::Path(path) }