fix: Python 3.7~3.8 bugs

.github/workflows/rust.yml

@@ -35,7 +35,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [windows-latest, ubuntu-latest, macos-latest]
-        python-version: ['3.9', '3.10', '3.11.3']
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11.3']
     runs-on: ${{ matrix.os }}
     env:
       RUST_BACKTRACE: full

crates/erg_compiler/codegen.rs

@@ -187,6 +187,7 @@ pub struct PyCodeGenerator {
     union_loaded: bool,
     fake_generic_loaded: bool,
     abc_loaded: bool,
+    builtins_loaded: bool,
     unit_size: usize,
     units: PyCodeGenStack,
     fresh_gen: SharedFreshNameGenerator,
@@ -209,6 +210,7 @@ impl PyCodeGenerator {
             union_loaded: false,
             fake_generic_loaded: false,
             abc_loaded: false,
+            builtins_loaded: false,
             unit_size: 0,
             units: PyCodeGenStack::empty(),
             fresh_gen: SharedFreshNameGenerator::new("codegen"),
@@ -231,6 +233,7 @@ impl PyCodeGenerator {
             union_loaded: false,
             fake_generic_loaded: false,
             abc_loaded: false,
+            builtins_loaded: false,
             unit_size: 0,
             units: PyCodeGenStack::empty(),
             fresh_gen: self.fresh_gen.clone(),
@@ -253,6 +256,7 @@ impl PyCodeGenerator {
         self.union_loaded = false;
         self.fake_generic_loaded = false;
         self.abc_loaded = false;
+        self.builtins_loaded = false;
     }
 
     #[inline]
@@ -2456,13 +2460,18 @@ impl PyCodeGenerator {
                 Some(7) => self.emit_with_instr_307(args),
                 _ => todo!("not supported Python version"),
             },
+            "sum" if self.py_version.minor <= Some(7) && args.get_kw("start").is_some() => {
+                self.load_builtins();
+                self.emit_load_name_instr(Identifier::private("#sum"));
+                self.emit_args_311(args, Name, true);
+            }
             other if local.ref_t().is_poly_type_meta() && other != "classof" => {
                 if self.py_version.minor <= Some(9) {
                     self.load_fake_generic();
                     self.emit_load_name_instr(Identifier::private("#FakeGenericAlias"));
                     let mut args = args;
                     args.insert_pos(0, PosArg::new(Expr::Accessor(Accessor::Ident(local))));
-                    self.emit_args_311(args, Name, false);
+                    self.emit_args_311(args, Name, true);
                 } else {
                     self.emit_load_name_instr(local);
                     self.emit_index_args(args);
@@ -3573,6 +3582,13 @@ impl PyCodeGenerator {
         );
     }
 
+    fn load_builtins(&mut self) {
+        self.emit_global_import_items(
+            Identifier::public("_erg_builtins"),
+            vec![(Identifier::public("sum"), Some(Identifier::private("#sum")))],
+        );
+    }
+
     pub fn emit(&mut self, hir: HIR) -> CodeObj {
         log!(info "the code-generating process has started.{RESET}");
         self.unit_size += 1;

crates/erg_compiler/context/initialize/funcs.rs

@@ -139,7 +139,7 @@ impl Context {
         let t_isinstance = nd_func(
             vec![
                 kw(KW_OBJECT, Obj),
-                kw(KW_CLASSINFO, ClassType), // TODO: => ClassInfo
+                kw(KW_CLASSINFO, ClassType | unknown_len_array_t(ClassType)), // TODO: => ClassInfo
             ],
             None,
             Bool,
@@ -147,7 +147,7 @@ impl Context {
         let t_issubclass = nd_func(
             vec![
                 kw(KW_SUBCLASS, ClassType),
-                kw(KW_CLASSINFO, ClassType), // TODO: => ClassInfo
+                kw(KW_CLASSINFO, ClassType | unknown_len_array_t(ClassType)), // TODO: => ClassInfo
             ],
             None,
             Bool,

crates/erg_compiler/hir.rs

@@ -385,6 +385,13 @@ impl Args {
     pub fn insert_pos(&mut self, idx: usize, pos: PosArg) {
         self.pos_args.insert(idx, pos);
     }
+
+    pub fn get_kw(&self, keyword: &str) -> Option<&Expr> {
+        self.kw_args
+            .iter()
+            .find(|kw| kw.keyword.inspect() == keyword)
+            .map(|kw| &kw.expr)
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]

crates/erg_compiler/lib/std/_erg_builtins.py

@@ -0,0 +1,6 @@
+# in Python 3.7, `sum` takes no keyword arguments
+def sum(iterable, start=0):
+    s = start
+    for i in iterable:
+        s += i
+    return s

crates/erg_compiler/lib/std/_erg_contains_operator.py

@@ -14,6 +14,8 @@ def contains_operator(y, elem) -> bool:
             return True
         elif hasattr(y, "try_new") and is_ok(y.try_new(elem)):
             return True
+        elif hasattr(y, "__origin__") and hasattr(y.__origin__, "type_check"):
+            return y.__origin__.type_check(elem, y)
         # TODO: trait check
         return False
     # [1] in [Int]