fix: type alias bug

crates/erg_compiler/context/initialize/classes.rs

@@ -1389,6 +1389,11 @@ impl Context {
             Visibility::BUILTIN_PUBLIC,
         );
         generic_array.register_trait(mono(GENERIC_ARRAY), array_hash);
+        let unsized_array_t = poly(UNSIZED_ARRAY, vec![ty_tp(T.clone())]);
+        let mut unsized_array =
+            Self::builtin_poly_class(UNSIZED_ARRAY, vec![ParamSpec::t_nd(TY_T)], 1);
+        unsized_array.register_superclass(Obj, &obj);
+        unsized_array.register_builtin_decl(KW_ELEM, T.clone(), vis.clone(), Some(KW_ELEM));
         /* Array */
         let mut array_ =
             Self::builtin_poly_class(ARRAY, vec![PS::t_nd(TY_T), PS::default(TY_N, Nat)], 10);
@@ -2994,6 +2999,13 @@ impl Context {
             Const,
             Some(ARRAY),
         );
+        self.register_builtin_type(
+            unsized_array_t,
+            unsized_array,
+            vis.clone(),
+            Const,
+            Some(UNSIZED_ARRAY),
+        );
         self.register_builtin_type(arr_t, array_, vis.clone(), Const, Some(ARRAY));
         self.register_builtin_type(mono(SLICE), slice, vis.clone(), Const, Some(FUNC_SLICE));
         self.register_builtin_type(

crates/erg_compiler/context/initialize/mod.rs

@@ -227,6 +227,7 @@ const PATH: &str = "Path";
 const MODULE: &str = "Module";
 const PY_MODULE: &str = "PyModule";
 const GENERIC_ARRAY: &str = "GenericArray";
+const UNSIZED_ARRAY: &str = "UnsizedArray";
 const ARRAY: &str = "Array";
 const MUT_ARRAY: &str = "Array!";
 const FUNC_UPDATE_NTH: &str = "update_nth";

crates/erg_compiler/context/instantiate_spec.rs

@@ -570,12 +570,7 @@ impl Context {
                         return Ok(t);
                     }
                 }
-                if let Some((typ, _)) = self.get_type_and_ctx(ident.inspect()) {
-                    if let Some((_, vi)) = self.get_var_info(ident.inspect()) {
-                        self.inc_ref(ident.inspect(), vi, ident, self);
-                    }
-                    Ok(typ.clone())
-                } else if let Some(typ) = self
+                if let Some(typ) = self
                     .consts
                     .get(ident.inspect())
                     .and_then(|v| self.convert_value_into_type(v.clone()).ok())
@@ -584,6 +579,11 @@ impl Context {
                         self.inc_ref(ident.inspect(), vi, ident, self);
                     }
                     Ok(typ)
+                } else if let Some((typ, _)) = self.get_type_and_ctx(ident.inspect()) {
+                    if let Some((_, vi)) = self.get_var_info(ident.inspect()) {
+                        self.inc_ref(ident.inspect(), vi, ident, self);
+                    }
+                    Ok(typ.clone())
                 } else if not_found_is_qvar {
                     let tyvar = named_free_var(Str::rc(other), self.level, Constraint::Uninited);
                     tmp_tv_cache.push_or_init_tyvar(&ident.name, &tyvar, self);

crates/erg_compiler/lower.rs

@@ -1735,21 +1735,18 @@ impl ASTLowerer {
             Ok(block) => {
                 let found_body_t = block.ref_t();
                 let outer = self.module.context.outer.as_ref().unwrap();
-                let opt_expect_body_t = sig
-                    .ident()
-                    .and_then(|ident| outer.get_current_scope_var(&ident.name))
-                    .map(|vi| vi.t.clone())
+                let opt_expect_body_t = self
+                    .module
+                    .context
+                    .instantiate_var_sig_t(
+                        sig.t_spec.as_ref().map(|ts| &ts.t_spec),
+                        RegistrationMode::PreRegister,
+                    )
+                    .ok()
                     .or_else(|| {
-                        // discard pattern
-                        let sig_t = self
-                            .module
-                            .context
-                            .instantiate_var_sig_t(
-                                sig.t_spec.as_ref().map(|ts| &ts.t_spec),
-                                RegistrationMode::PreRegister,
-                            )
-                            .ok();
-                        sig_t
+                        sig.ident()
+                            .and_then(|ident| outer.get_current_scope_var(&ident.name))
+                            .map(|vi| vi.t.clone())
                     });
                 let ident = match &sig.pat {
                     ast::VarPattern::Ident(ident) => ident.clone(),

crates/erg_parser/ast.rs

@@ -3135,8 +3135,7 @@ impl VarName {
             .content
             .chars()
             .next()
-            .map(|c| c.is_uppercase())
-            .unwrap_or(false)
+            .map_or(false, |c| c.is_uppercase())
     }
 
     #[inline]
@@ -3146,12 +3145,7 @@ impl VarName {
 
     #[inline]
     pub fn is_procedural(&self) -> bool {
-        self.0
-            .content
-            .chars()
-            .last()
-            .map(|c| c == '!')
-            .unwrap_or(false)
+        self.0.content.chars().last().map_or(false, |c| c == '!')
     }
 
     pub fn is_raw(&self) -> bool {

tests/should_err/advanced_type_spec.er

@@ -0,0 +1,2 @@
+Packages = [{ .name = Str; .version = Str }; _]
+_: Packages = [{ .name = "a"; }]

tests/should_ok/advanced_type_spec.er

@@ -12,3 +12,6 @@ _: Iterable(Dict({Str: Int})) = [{"a": 1}]
 f2|T|(_: Structural { .a = (self: T) -> Obj }): NoneType = None
 g2: (|T|(_: Structural { .a = (self: T) -> Obj }) -> NoneType) = f2
 _, _ = f2, g2
+
+Packages = [{ .name = Str; .version = Str }; _]
+_: Packages = [{ .name = "a"; .version = "b" }]

tests/test.rs

@@ -396,6 +396,11 @@ fn exec_addition_err() -> Result<(), ()> {
     expect_failure("tests/should_err/addition.er", 3, 9)
 }
 
+#[test]
+fn exec_advanced_type_spec_err() -> Result<(), ()> {
+    expect_failure("tests/should_err/advanced_type_spec.er", 0, 1)
+}
+
 #[test]
 fn exec_args() -> Result<(), ()> {
     expect_failure("tests/should_err/args.er", 0, 19)