refactoring

Author: tyralla

mypy/checker.py

@@ -641,10 +641,7 @@ def accept_loop(
                 if iter == 20:
                     raise RuntimeError("Too many iterations when checking a loop")
 
-            for error_info in watcher.yield_error_infos():
-                self.msg.fail(*error_info[:2], code=error_info[2])
-            for note_info, context in watcher.yield_note_infos():
-                self.msg.reveal_type(note_info, context)
+            self.msg.iteration_dependent_errors(iter_errors)
 
             # If exit_condition is set, assume it must be False on exit from the loop:
             if exit_condition:
@@ -4984,11 +4981,7 @@ def visit_try_stmt(self, s: TryStmt) -> None:
             if not self.binder.is_unreachable():
                 with IterationErrorWatcher(self.msg.errors, iter_errors) as watcher:
                     self.accept(s.finally_body)
-
-            for error_info in watcher.yield_error_infos():
-                self.msg.fail(*error_info[:2], code=error_info[2])
-            for note_info, context in watcher.yield_note_infos():
-                self.msg.reveal_type(note_info, context)
+            self.msg.iteration_dependent_errors(iter_errors)
 
     def visit_try_without_finally(self, s: TryStmt, try_frame: bool) -> None:
         """Type check a try statement, ignoring the finally block.

mypy/errors.py

@@ -255,6 +255,33 @@ def __init__(self) -> None:
         self.revealed_types = defaultdict(list)
 
 
+    def yield_uselessness_error_infos(self) -> Iterator[tuple[str, Context, ErrorCode]]:
+        """Report only those `unreachable`, `redundant-expr`, and `redundant-casts`
+        errors that could not be ruled out in any iteration step."""
+
+        persistent_uselessness_errors = set()
+        for candidate in set(chain(*self.uselessness_errors)):
+            if all(
+                (candidate in errors) or (candidate[2] in lines)
+                for errors, lines in zip(self.uselessness_errors, self.unreachable_lines)
+            ):
+                persistent_uselessness_errors.add(candidate)
+        for error_info in persistent_uselessness_errors:
+            context = Context(line=error_info[2], column=error_info[3])
+            context.end_line = error_info[4]
+            context.end_column = error_info[5]
+            yield error_info[1], context, error_info[0]
+
+    def yield_revealed_type_infos(self) -> Iterator[tuple[Type, Context]]:
+        """Yield all types revealed in at least one iteration step."""
+
+        for note_info, types in self.revealed_types.items():
+            context = Context(line=note_info[0], column=note_info[1])
+            context.end_line = note_info[2]
+            context.end_column = note_info[3]
+            yield make_simplified_union(types), context
+
+
 class IterationErrorWatcher(ErrorWatcher):
     """Error watcher that filters and separately collects `unreachable` errors,
     `redundant-expr` and `redundant-casts` errors, and revealed types when analysing
@@ -297,35 +324,6 @@ def on_error(self, file: str, info: ErrorInfo) -> bool:
 
         return super().on_error(file, info)
 
-    def yield_error_infos(self) -> Iterator[tuple[str, Context, ErrorCode]]:
-        """Report only those `unreachable`, `redundant-expr`, and `redundant-casts`
-        errors that could not be ruled out in any iteration step."""
-
-        persistent_uselessness_errors = set()
-        iter_errors = self.iteration_dependent_errors
-        for candidate in set(chain(*iter_errors.uselessness_errors)):
-            if all(
-                (candidate in errors) or (candidate[2] in lines)
-                for errors, lines in zip(
-                    iter_errors.uselessness_errors, iter_errors.unreachable_lines
-                )
-            ):
-                persistent_uselessness_errors.add(candidate)
-        for error_info in persistent_uselessness_errors:
-            context = Context(line=error_info[2], column=error_info[3])
-            context.end_line = error_info[4]
-            context.end_column = error_info[5]
-            yield error_info[1], context, error_info[0]
-
-    def yield_note_infos(self) -> Iterator[tuple[Type, Context]]:
-        """Yield all types revealed in at least one iteration step."""
-
-        for note_info, types in self.iteration_dependent_errors.revealed_types.items():
-            context = Context(line=note_info[0], column=note_info[1])
-            context.end_line = note_info[2]
-            context.end_column = note_info[3]
-            yield make_simplified_union(types), context
-
 
 class Errors:
     """Container for compile errors.

mypy/messages.py

@@ -23,7 +23,13 @@
 from mypy import errorcodes as codes, message_registry
 from mypy.erasetype import erase_type
 from mypy.errorcodes import ErrorCode
-from mypy.errors import ErrorInfo, Errors, ErrorWatcher, IterationErrorWatcher
+from mypy.errors import (
+    ErrorInfo,
+    Errors,
+    ErrorWatcher,
+    IterationDependentErrors,
+    IterationErrorWatcher,
+)
 from mypy.nodes import (
     ARG_NAMED,
     ARG_NAMED_OPT,
@@ -2501,6 +2507,12 @@ def match_statement_inexhaustive_match(self, typ: Type, context: Context) -> Non
             code=codes.EXHAUSTIVE_MATCH,
         )
 
+    def iteration_dependent_errors(self, iter_errors: IterationDependentErrors) -> None:
+        for error_info in iter_errors.yield_uselessness_error_infos():
+            self.fail(*error_info[:2], code=error_info[2])
+        for note_info, context in iter_errors.yield_revealed_type_infos():
+            self.reveal_type(note_info, context)
+
 
 def quote_type_string(type_string: str) -> str:
     """Quotes a type representation for use in messages."""