Replace usages of typing.cast

It is no safer than type annotations and `type: ignore` comments, and it
doesn’t stand out as much as those do.

pyproject.toml

@@ -145,6 +145,9 @@ builtins-ignorelist = [
 inline-quotes = "single"
 multiline-quotes = "single"
 
+[tool.ruff.lint.flake8-tidy-imports.banned-api]
+"typing.cast".msg = "Use a type annotation or `# type: ignore` instead"
+
 [tool.ruff.lint.flake8-type-checking]
 quote-annotations = true
 strict = true

sources/charsets/data.py

@@ -24,7 +24,6 @@
 from typing import Final
 from typing import TYPE_CHECKING
 from typing import assert_never
-from typing import cast
 import unicodedata
 
 import gfsubsets
@@ -356,7 +355,7 @@ def initialize_schemas(charset: Charset, light_line: float, stroke_gap: float) -
     high_vertical_secant = Line(90, secant=1 / 3)
     rtl_secant = Line(240, secant=0.5, secant_curvature_offset=55)
     ltr_secant = Line(310, secant=0.5, secant_curvature_offset=55)
-    tangent = Complex([lambda c: Context(None if c.angle is None else (c.angle - 90) % 360 if 90 < c.angle < 315 else (c.angle + 90) % 360), (0.25, Line(270), True), lambda c: Context((cast(float, c.angle) + 180) % 360), (0.5, Line(90))])
+    tangent = Complex([lambda c: Context(None if c.angle is None else (c.angle - 90) % 360 if 90 < c.angle < 315 else (c.angle + 90) % 360), (0.25, Line(270), True), lambda c: Context((c.angle + 180) % 360), (0.5, Line(90))])  # type: ignore[operator]
     e_hook = Curve(90, 270, clockwise=True, hook=True, may_reposition_cursive_endpoints=True)
     i_hook = Curve(180, 0, clockwise=False, hook=True, may_reposition_cursive_endpoints=True)
     tangent_hook = TangentHook([(1, Curve(180, 270, clockwise=False), True), Context.as_reversed, (1, Curve(90, 270, clockwise=True))])
@@ -393,7 +392,7 @@ def initialize_schemas(charset: Charset, light_line: float, stroke_gap: float) -
     first_quarter_moon = Complex([(0, Dot(1.5498)), (4, Line(180), True), (12, Line(270), True), (100, Curve(180, 180 - 10, clockwise=True), True), (100, Curve(360 - 10, 180 + 10, clockwise=False)), (100 / (1 + 0.3), Curve(10, 180 - 10, clockwise=True, stretch=0.3, stretch_axis=StretchAxis.ABSOLUTE)), (4.08, Line(70)), (200, Curve(3.8, 11.3, clockwise=False)), (200, Curve(180 + 11.3, 180 + 3.8, clockwise=True), True), (2, Line(80)), (1.5, Line(180), True), (20, Curve(0, 33.4, clockwise=False, stretch=1.4, long=True, stretch_axis=StretchAxis.ANGLE_OUT), True), (20, Curve(180 + 33.4, 90 + 33.4, clockwise=True, stretch=1.4, long=True)), (20, Curve(90 + 33.4, 37.8, clockwise=True, stretch=1.1, long=True, stretch_axis=StretchAxis.ANGLE_OUT)), (36, Curve(37.8, 125, clockwise=False, stretch=0.1, stretch_axis=StretchAxis.ANGLE_OUT)), (36, Curve(125, 68, clockwise=True, stretch=0.1, stretch_axis=StretchAxis.ABSOLUTE))])
     full_moon = Complex([(100, Circle(0, 0, clockwise=False)), (4, Line(90), True), (200, Curve(180, 180 - 11.3, clockwise=True), True), (200, Curve(360 - 11.3, 11.3, clockwise=False)), (200, Curve(180 + 11.3, 180, clockwise=True), True), (8, Line(90), True), (4, Line(180), True), (0, Dot(1.5498)), (2, Line(90), True), (60, Curve(0, 360 - 22.9, clockwise=True), True), (60, Curve(180 - 22.9, 180 + 22.9, clockwise=False)), (60, Curve(22.9, 0, clockwise=True), True), (2, Line(270), True), (2 * 4, Line(0), True), (0, Dot(1.5498)), (2, Line(90), True), (60, Curve(0, 360 - 22.9, clockwise=True), True), (60, Curve(180 - 22.9, 180 + 22.9, clockwise=False)), (20, Curve(180 + 22.9, 276.1, clockwise=False)), (20, Curve(276.1, 282.2, clockwise=False, stretch=0.5, long=True, stretch_axis=StretchAxis.ANGLE_OUT)), (60, Curve(282.2, 288.3, clockwise=False, stretch=1, long=True, stretch_axis=StretchAxis.ANGLE_OUT)), (1, Line(288.3)), (25, Curve(180 + 53.3, 180 - 53.3, clockwise=True))])
     last_quarter_moon = Complex([op._replace(shape=op.shape.clone(angle_in=180 - op.shape.angle_in, angle_out=180 - op.shape.angle_out, clockwise=not op.shape.clockwise) if isinstance(op.shape, Circle | Curve) else op.shape.clone(angle=180 - op.shape.angle) if isinstance(op.shape, Line) else op.shape) for op in first_quarter_moon.instructions])  # type: ignore[union-attr]
-    new_moon = Complex([*[(cast(float, op[0]) * full_moon.instructions[0].size * RADIUS / LINE_FACTOR, *op[1:]) for i in range(8) for op in [(math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(90), True), (2 * math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(270)), (math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(90), True), (2 / (8 + 1), Line(0), True)]], (full_moon.instructions[0].size * RADIUS / LINE_FACTOR * math.sqrt(2), Line(225), True), *full_moon.instructions])  # type: ignore[list-item, union-attr]
+    new_moon = Complex([*[(op[0] * full_moon.instructions[0].size * RADIUS / LINE_FACTOR, *op[1:]) for i in range(8) for op in [(math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(90), True), (2 * math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(270)), (math.sqrt(1 - ((i - (8 + 1) / 2 + 1) / (8 / 2)) ** 2) * (1.25 if i in {0, 8 - 1} else 0.95 if abs((i - (8 + 1) / 2 + 1) / (8 / 2)) < 0.5 else 1), Line(90), True), (2 / (8 + 1), Line(0), True)]], (full_moon.instructions[0].size * RADIUS / LINE_FACTOR * math.sqrt(2), Line(225), True), *full_moon.instructions])  # type: ignore[list-item, operator, union-attr]
     line = Line(0)
 
     enclosing_circle = Schema(None, circle, 10, anchor=anchors.MIDDLE)

sources/duployan.py

@@ -19,7 +19,6 @@
 import math
 from typing import Final
 from typing import TYPE_CHECKING
-from typing import cast
 
 import fontTools.agl
 import fontTools.feaLib.ast
@@ -493,10 +492,10 @@ def _recreate_gdef(self) -> None:
 
     @staticmethod
     def _glyph_to_schema(glyph: fontforge.glyph) -> Schema:
-        schema = glyph.temporary
+        schema: Schema = glyph.temporary
         glyph.temporary = None
         schema.glyph = glyph
-        return cast(Schema, schema)
+        return schema
 
     def convert_classes(
         self,

sources/phases/__init__.py

@@ -90,7 +90,6 @@
 import itertools
 from typing import Final
 from typing import TYPE_CHECKING
-from typing import cast
 from typing import overload
 from typing import override
 
@@ -1267,7 +1266,7 @@ def run_phases(
                             break
                 case _:
                     might_have_feedback = True
-            features = {cast(str, lookup.feature) for lookup in lookups}
+            features: set[str] = {lookup.feature for lookup in lookups}  # type: ignore[misc]
             for output_schema in output_schemas:
                 all_output_schemas.add(output_schema)
             new_input_schemas = OrderedSet()

sources/schema.py

@@ -19,14 +19,12 @@
 
 from __future__ import annotations
 
-from collections.abc import Mapping
 import enum
 import functools
 import re
 from typing import Final
 from typing import Self
 from typing import TYPE_CHECKING
-from typing import cast
 from typing import override
 import unicodedata
 
@@ -69,6 +67,7 @@
     from collections.abc import Collection
     from collections.abc import Hashable
     from collections.abc import Iterable
+    from collections.abc import Mapping
     from collections.abc import MutableMapping
     from collections.abc import MutableSequence
     from collections.abc import Sequence
@@ -766,7 +765,8 @@ def _agl_name(cp: int) -> str:
             ValueError: If `cp` is not ASCII.
         """
         if cp <= 0x7F:
-            return cast(Mapping[int, str], fontTools.agl.UV2AGL)[cp]
+            uv2agl: Mapping[int, str] = fontTools.agl.UV2AGL
+            return uv2agl[cp]
         raise ValueError
 
     @staticmethod

sources/shapes.py

@@ -30,7 +30,6 @@
 from typing import NamedTuple
 from typing import Self
 from typing import TYPE_CHECKING
-from typing import cast
 from typing import override
 
 import fontTools.misc.transform
@@ -3354,7 +3353,8 @@ def boundingBox(self) -> tuple[float, float, float, float]:
                 minimum x, minimum y, maximum x, and maximum y.
             """
             layer = self._stroke(copy=True)
-            return cast(tuple[float, float, float, float], layer.boundingBox())
+            bounding_box: tuple[float, float, float, float] = layer.boundingBox()
+            return bounding_box
 
         def draw(
             self,
@@ -4475,7 +4475,7 @@ def enter_on_first_path(self) -> bool:
     def contextualize(self, context_in: Context, context_out: Context) -> Shape:
         context_in = context_in.clone(ignorable_for_topography=False)
         context_out = context_out.clone(ignorable_for_topography=False)
-        original_instructions = cast(list[Component], self.instructions)
+        original_instructions: Sequence[Component] = self.instructions  # type: ignore[assignment]
         if context_in == NO_CONTEXT and context_out != NO_CONTEXT:
             assert context_out.angle is not None
             outer_circle_op = original_instructions[0]
@@ -4760,7 +4760,7 @@ def contextualize(self, context_in: Context, context_out: Context) -> Shape:
                 ), *self.instructions[3][2:]),
             ], _initial=True)
         else:
-            shape = cast(Self, super())
+            shape = super()  # type: ignore[assignment]
         return shape.contextualize(context_in, context_out)