fix(checker): use dispatcher in frame method registry

midas/checker/frame_methods.py

@@ -3,7 +3,9 @@ from __future__ import annotations
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Callable, Optional
 
+import midas.ast.python as p
 from midas.ast.location import Location
+from midas.checker.dispatcher import CallDispatcher, CallResult
 from midas.checker.registry import TypesRegistry
 from midas.checker.reporter import FileReporter
 from midas.checker.types import (
@@ -71,6 +73,10 @@ class MethodRegistry(metaclass=_MethodRegistryMeta):
     def types(self) -> TypesRegistry:
         return self.typer.types
 
+    @property
+    def dispatcher(self) -> CallDispatcher[p.Expr]:
+        return self.typer.dispatcher
+
     def call(
         self,
         method: str,
@@ -147,15 +153,13 @@ class MethodRegistry(metaclass=_MethodRegistryMeta):
             returns=DataFrameType(columns=new_columns),
         )
 
-        return (
-            self.typer._get_call_result(
+        result: CallResult = self.dispatcher.get_result(
             location=call.location,
             callee=signature,
             positional=call.positional,
             keywords=call.keywords,
         )
-            or UnknownType()
-        )
+        return result.result
 
     @frame_method()
     def mean(self, call: Call) -> Type:
@@ -187,12 +191,11 @@ class MethodRegistry(metaclass=_MethodRegistryMeta):
                 without_axis,
             ]
         )
-        return (
-            self.typer._get_call_result(
+
+        result: CallResult = self.dispatcher.get_result(
             location=call.location,
             callee=overload,
             positional=call.positional,
             keywords=call.keywords,
         )
-            or UnknownType()
-        )
+        return result.result