fix(checker): handle application of column type

midas/checker/midas.py

@@ -383,6 +383,16 @@ class MidasTyper(m.Stmt.Visitor[None], m.Expr.Visitor[Type], m.Type.Visitor[Type
             return UnknownType()
 
     def visit_generic_type(self, type: m.GenericType) -> Type:
+        match type.type:
+            case m.NamedType(name=Token(lexeme="Column")):
+                if len(type.args) != 1:
+                    self.reporter.error(
+                        type.location,
+                        f"Column requires 1 type argument, {len(type.args)} provided",
+                    )
+                    return ColumnType(type=UnknownType())
+                return ColumnType(type=type.args[0].accept(self))
+
         type_: Type = type.type.accept(self)
         args: list[Type] = [arg.accept(self) for arg in type.args]
         try:

midas/checker/python.py

@@ -938,6 +938,15 @@ class PythonTyper(
         return UnknownType()
 
     def visit_base_type(self, node: p.BaseType) -> Type:
+        if node.base == "Column":
+            if len(node.args) != 1:
+                self.reporter.error(
+                    node.location,
+                    f"Column requires 1 type argument, {len(node.args)} provided",
+                )
+                return ColumnType(type=UnknownType())
+            return ColumnType(type=self.resolve_type_expr(node.args[0]))
+
         base: Type
         try:
             base = self.types.get_type(node.base)