feat: trait associated type bounds

compiler/noirc_frontend/src/ast/traits.rs

@@ -49,6 +49,7 @@ pub enum TraitItem {
     },
     Type {
         name: Ident,
+        bounds: Vec<TraitBound>,
     },
 }
 
@@ -215,7 +216,14 @@ impl Display for TraitItem {
                     write!(f, ";")
                 }
             }
-            TraitItem::Type { name } => write!(f, "type {name};"),
+            TraitItem::Type { name, bounds } => {
+                if bounds.is_empty() {
+                    write!(f, "type {name};")
+                } else {
+                    let bounds = vecmap(bounds, |bound| bound.to_string()).join(" + ");
+                    write!(f, "type {name}: {bounds};")
+                }
+            }
         }
     }
 }

compiler/noirc_frontend/src/ast/visitor.rs

@@ -132,7 +132,9 @@ pub trait Visitor {
         true
     }
 
-    fn visit_trait_item_type(&mut self, _: &Ident) {}
+    fn visit_trait_item_type(&mut self, _: &Ident, _: &[TraitBound]) -> bool {
+        true
+    }
 
     fn visit_use_tree(&mut self, _: &UseTree) -> bool {
         true
@@ -788,7 +790,13 @@ impl TraitItem {
                     }
                 }
             }
-            TraitItem::Type { name } => visitor.visit_trait_item_type(name),
+            TraitItem::Type { name, bounds } => {
+                if visitor.visit_trait_item_type(name, bounds) {
+                    for bound in bounds {
+                        bound.accept(visitor);
+                    }
+                }
+            }
         }
     }
 }

compiler/noirc_frontend/src/elaborator/enums.rs

@@ -250,6 +250,7 @@
             location,
             has_body: false,
             trait_constraints: Vec::new(),
+            extra_trait_constraints: Vec::new(),
             type_id: Some(type_id),
             trait_id: None,
             trait_impl: None,
@@ -1005,7 +1006,7 @@
 
     /// Compiles the cases and fallback cases for integer and range patterns.
     ///
     /// Integers have an infinite number of constructors, so we specialise the
     /// compilation of integer and range patterns.
     fn compile_int_cases(
         &mut self,