Update stuff

trans/transpiler/phases/emit_cpp/expr.py

@@ -221,7 +221,7 @@ class ExpressionVisitor(NodeVisitor):
         use_dot = None
         if type(node.value.type) == TypeType:
             use_dot = "dots"
-        elif isinstance(node.type, FunctionType) and not isinstance(node.value.type, Promise):
+        elif isinstance(node.type, FunctionType) and node.type.is_method and not isinstance(node.value.type, Promise):
             if node.value.type.resolve().is_reference:
                 use_dot =  "dotp"
             else:

trans/transpiler/phases/typing/exceptions.py

@@ -284,4 +284,22 @@ class OutsideLoopError(CompileError):
         return f"{highlight('break')} and {highlight('continue')} can only be used inside a loop"
 
     def detail(self, last_node: ast.AST = None) -> str:
-        return ""
\ No newline at end of file
+        return ""
+
+@dataclass
+class MissingReturnError(CompileError):
+    node: ast.FunctionDef
+
+    def __str__(self) -> str:
+        return f"Missing return: not all code paths in {highlight(self.node)} return"
+
+    def detail(self, last_node: ast.AST = None) -> str:
+        return f"""
+        This indicates that a function is missing a {highlight('return')} statement in one or more of its code paths.
+        
+        For example:
+            {highlight('def f(x: int):')}
+            {highlight('    if x > 0:')}
+            {highlight('        return 1')}
+            {highlight('    # if x <= 0, the function returns nothing')}
+        """
\ No newline at end of file

trans/transpiler/phases/typing/expr.py

@@ -67,7 +67,7 @@ class ScoperExprVisitor(ScoperVisitor):
         assert ftype.kind == PromiseKind.TASK
         ftype.kind = PromiseKind.GENERATOR
         ftype.return_type.unify(ytype)
-        self.scope.function.has_return = True
+        self.scope.function.has_yield = True
 
         return TY_NONE
 

trans/transpiler/phases/typing/scope.py

@@ -54,7 +54,7 @@ class Scope:
     vars: Dict[str, VarDecl] = field(default_factory=dict)
     children: List["Scope"] = field(default_factory=list)
     obj_type: Optional[BaseType] = None
-    has_return: bool = False
+    diverges: bool = False
     class_: Optional["Scope"] = None
     is_loop: Optional[ast.For | ast.While] = None
 

trans/transpiler/phases/typing/stdlib.py

@@ -105,6 +105,7 @@ class StdlibVisitor(NodeVisitorSeq):
             ty.variadic = True
         ty.optional_at = 1 + len(node.args.args) - len(node.args.defaults)
         if self.cur_class:
+            ty.is_method = True
             assert isinstance(self.cur_class, TypeType)
             if isinstance(self.cur_class.type_object, ABCMeta):
                 self.cur_class.type_object.gen_methods[node.name] = lambda t: ty.gen_sub(t, self.typevars)

trans/transpiler/phases/typing/types.py

@@ -289,12 +289,12 @@ class TypeOperator(BaseType, ABC):
             vardict = dict(zip(typevars.keys(), this.args))
         else:
             vardict = typevars
-        for k in dataclasses.fields(self):
-            setattr(res, k.name, getattr(self, k.name))
+        for k, v in self.__dict__.items():
+            setattr(res, k, v)
         res.args = [arg.resolve().gen_sub(this, vardict, cache) for arg in self.args]
         res.methods = {k: v.gen_sub(this, vardict, cache) for k, v in self.methods.items()}
         res.parents = [p.gen_sub(this, vardict, cache) for p in self.parents]
-        res.is_protocol = self.is_protocol
+        #res.is_protocol = self.is_protocol
         return res
 
     def to_list(self) -> List["BaseType"]:
@@ -308,6 +308,7 @@ class ModuleType(TypeOperator):
 class FunctionType(TypeOperator):
     is_python_func: bool = False
     python_func_used: bool = False
+    is_method: bool = False
 
     def __iter__(self):
         x = 5
@@ -331,16 +332,19 @@ class FunctionType(TypeOperator):
 
     def __str__(self):
         ret, *args = map(str, self.args)
+        if self.optional_at is not None:
+            args = args[:self.optional_at] + [f"{x}=..." for x in args[self.optional_at:]]
         if self.variadic:
-            args.append(f"*args")
+            args.append("*args")
         if args:
-            args = f"({', '.join(args)})"
+            args = f"{', '.join(args)}"
         else:
-            args = "()"
-        return f"{args} -> {ret}"
+            args = ""
+        return f"({args}) -> {ret}"
 
     def remove_self(self):
         res = FunctionType(self.parameters[1:], self.return_type)
+        res.is_method = self.is_method
         res.variadic = self.variadic
         res.optional_at = self.optional_at - 1 if self.optional_at is not None else None
         return res
@@ -460,8 +464,12 @@ class Promise(TypeOperator, ABC):
     @kind.setter
     def kind(self, value: PromiseKind):
         if value == PromiseKind.GENERATOR:
-            self.methods["__iter__"] = FunctionType([], self)
-            self.methods["__next__"] = FunctionType([], self.return_type)
+            f_iter = FunctionType([], self)
+            f_iter.is_method = True
+            self.methods["__iter__"] = f_iter
+            f_next = FunctionType([], self.return_type)
+            f_next.is_method = True
+            self.methods["__next__"] = f_next
         self.args[1].val = value
 
     def __str__(self):
@@ -506,4 +514,10 @@ class UserType(TypeOperator):
 class UnionType(TypeOperator):
     def __init__(self, *args: List[BaseType]):
         super().__init__(args, "Union")
-        self.parents.extend(args)
+        self.parents.extend(set(args))
+
+    def is_optional(self):
+        if len(self.args) == 2 and TY_NONE in self.args:
+            return (set(self.args) - {TY_NONE}).pop()
+        return False
+