feat(syntax,semantic,lowering): support tuple struct syntax (struct Foo(T1, T2))

crates/cairo-lang-defs/src/db.rs

@@ -1395,13 +1395,15 @@ fn validate_attributes<'db>(
             }
         }
         ast::ModuleItem::Struct(item) => {
-            validate_attributes_element_list(
-                db,
-                allowed_attributes,
-                &extra_allowed_attributes,
-                item.members(db).elements(db),
-                plugin_diagnostics,
-            );
+            if let ast::StructBody::Braces(body) = item.body(db) {
+                validate_attributes_element_list(
+                    db,
+                    allowed_attributes,
+                    &extra_allowed_attributes,
+                    body.members(db).elements(db),
+                    plugin_diagnostics,
+                );
+            }
         }
         ast::ModuleItem::Enum(item) => {
             validate_attributes_element_list(

crates/cairo-lang-defs/src/ids.rs

@@ -992,7 +992,8 @@ define_named_language_element_id!(MemberId, MemberLongId, ast::Member<'db>);
 impl<'db> MemberId<'db> {
     pub fn struct_id(&self, db: &'db dyn Database) -> StructId<'db> {
         let MemberLongId(module_id, ptr) = self.long(db).clone();
-        let struct_ptr = ast::ItemStructPtr(ptr.untyped().nth_parent(db, 2));
+        // Member -> MemberList -> StructBodyBraces -> ItemStruct (3 levels up).
+        let struct_ptr = ast::ItemStructPtr(ptr.untyped().nth_parent(db, 3));
         StructLongId(module_id, struct_ptr).intern(db)
     }
 }

crates/cairo-lang-lowering/src/lower/mod.rs

@@ -1834,12 +1834,30 @@ fn lower_expr_member_access<'db>(
                 .collect();
             (member_tys, member_idx)
         }
-        TypeMemberKind::TupleElement(idx) => {
-            let tys = extract_matches!(container_long_ty, TypeLongId::Tuple);
-            let member_tys =
-                tys.iter().map(|&ty| wrap_in_snapshots(ctx.db, ty, expr.n_snapshots)).collect();
-            (member_tys, *idx)
-        }
+        TypeMemberKind::TupleElement(idx) => match container_long_ty {
+            TypeLongId::Tuple(tys) => {
+                let member_tys =
+                    tys.iter().map(|&ty| wrap_in_snapshots(ctx.db, ty, expr.n_snapshots)).collect();
+                (member_tys, *idx)
+            }
+            TypeLongId::Concrete(semantic::ConcreteTypeId::Struct(concrete_struct_id)) => {
+                let positional_tys = ctx
+                    .db
+                    .concrete_struct_positional_types(concrete_struct_id)
+                    .map_err(LoweringFlowError::Failed)?
+                    .ok_or_else(|| {
+                        LoweringFlowError::Failed(
+                            ctx.diagnostics.report(expr.stable_ptr.untyped(), UnexpectedError),
+                        )
+                    })?;
+                let member_tys = positional_tys
+                    .iter()
+                    .map(|&(ty, _)| wrap_in_snapshots(ctx.db, ty, expr.n_snapshots))
+                    .collect();
+                (member_tys, *idx)
+            }
+            _ => unreachable!("TupleElement access on unexpected container type"),
+        },
     };
     Ok(LoweredExpr::AtVariable(
         generators::StructMemberAccess {

crates/cairo-lang-parser/src/parser.rs

@@ -486,7 +486,8 @@ impl<'a, 'mt> Parser<'a, 'mt> {
     }
 
     /// Assumes the current token is Struct.
-    /// Expected pattern: `struct<Identifier>{<ParamList>}`
+    /// Expected pattern: `struct<Identifier>{<MemberList>}` or
+    /// `struct<Identifier>(<StructArgMemberList>)`.
     fn expect_item_struct(
         &mut self,
         attributes: AttributeListGreen<'a>,
@@ -495,22 +496,52 @@ impl<'a, 'mt> Parser<'a, 'mt> {
         let struct_kw = self.take::<TerminalStruct<'_>>();
         let name = self.parse_identifier();
         let generic_params = self.parse_optional_generic_params();
-        let lbrace = self.parse_token::<TerminalLBrace<'_>>();
-        let members = self.parse_member_list();
-        let rbrace = self.parse_token::<TerminalRBrace<'_>>();
+        let body = if self.peek().kind == SyntaxKind::TerminalLParen {
+            let lparen = self.take::<TerminalLParen<'_>>();
+            let members = self.parse_struct_arg_member_list();
+            let rparen = self.parse_token::<TerminalRParen<'_>>();
+            StructBodyParens::new_green(self.db, lparen, members, rparen).into()
+        } else {
+            let lbrace = self.parse_token::<TerminalLBrace<'_>>();
+            let members = self.parse_member_list();
+            let rbrace = self.parse_token::<TerminalRBrace<'_>>();
+            StructBodyBraces::new_green(self.db, lbrace, members, rbrace).into()
+        };
         ItemStruct::new_green(
             self.db,
             attributes,
             visibility,
             struct_kw,
             name,
             generic_params,
-            lbrace,
-            members,
-            rbrace,
+            body,
         )
     }
 
+    /// Returns a GreenId of a node with kind StructArgMemberList.
+    fn parse_struct_arg_member_list(&mut self) -> StructArgMemberListGreen<'a> {
+        StructArgMemberList::new_green(
+            self.db,
+            &self.parse_separated_list::<
+                StructArgMember<'_>,
+                TerminalComma<'_>,
+                StructArgMemberListElementOrSeparatorGreen<'_>,
+            >(
+                Self::try_parse_struct_arg_member,
+                is_of_kind!(rparen, block, lbrace, rbrace, module_item_kw),
+                "type",
+            ),
+        )
+    }
+
+    /// Returns a GreenId of a node with kind StructArgMember, or TryParseFailure if a positional
+    /// struct member can't be parsed.
+    fn try_parse_struct_arg_member(&mut self) -> TryParseResult<StructArgMemberGreen<'a>> {
+        let visibility = self.parse_visibility();
+        let ty = self.try_parse_type_expr()?;
+        Ok(StructArgMember::new_green(self.db, visibility, ty))
+    }
+
     /// Assumes the current token is Enum.
     /// Expected pattern: `enum<Identifier>{<ParamList>}`
     fn expect_item_enum(