ENH: Add support for all potential extended-precision `np.number`s

2 files changed, 56 insertions, 4 deletions

diff --git a/numpy/__init__.pyi b/numpy/__init__.pyi
index b29ba38da..0312dfad0 100644
--- a/numpy/__init__.pyi
+++ b/numpy/__init__.pyi
@@ -127,6 +127,20 @@ from numpy.typing._callable import (
     _NumberOp,
     _ComparisonOp,
 )
+from numpy.typing._extended_precision import (
+    uint128 as uint128,
+    uint256 as uint256,
+    int128 as int128,
+    int256 as int256,
+    float80 as float80,
+    float96 as float96,
+    float128 as float128,
+    float256 as float256,
+    complex160 as complex160,
+    complex192 as complex192,
+    complex256 as complex256,
+    complex512 as complex512,
+)
 
 from typing import (
     Any,
@@ -2195,7 +2209,6 @@ class floating(inexact[_NBit1]):
 float16 = floating[_16Bit]
 float32 = floating[_32Bit]
 float64 = floating[_64Bit]
-float128 = floating[_128Bit]
 
 half = floating[_NBitHalf]
 single = floating[_NBitSingle]
@@ -2230,7 +2243,6 @@ class complexfloating(inexact[_NBit1], Generic[_NBit1, _NBit2]):
 
 complex64 = complexfloating[_32Bit, _32Bit]
 complex128 = complexfloating[_64Bit, _64Bit]
-complex256 = complexfloating[_128Bit, _128Bit]
 
 csingle = complexfloating[_NBitSingle, _NBitSingle]
 singlecomplex = complexfloating[_NBitSingle, _NBitSingle]
@@ -2284,8 +2296,6 @@ class str_(character, str):
 unicode_ = str_
 str0 = str_
 
-# TODO: Platform dependent types: float128, complex256, float96
-
 def array(
     object: object,
     dtype: DTypeLike = ...,
diff --git a/numpy/typing/_extended_precision.py b/numpy/typing/_extended_precision.py
new file mode 100644
index 000000000..3f1ce2038
--- /dev/null
+++ b/numpy/typing/_extended_precision.py
@@ -0,0 +1,42 @@
+"""A module with platform-specific extended precision `numpy.number` subclasses.
+
+The subclasses are defined here (instead of ``__init__.pyi``) such
+that they can be imported conditionally via the numpy's mypy plugin.
+"""
+
+from typing import TYPE_CHECKING
+
+import numpy as np
+from . import (
+    _80Bit,
+    _96Bit,
+    _128Bit,
+    _256Bit,
+)
+
+if TYPE_CHECKING:
+    uint128 = np.unsignedinteger[_128Bit]
+    uint256 = np.unsignedinteger[_256Bit]
+    int128 = np.signedinteger[_128Bit]
+    int256 = np.signedinteger[_256Bit]
+    float80 = np.floating[_80Bit]
+    float96 = np.floating[_96Bit]
+    float128 = np.floating[_128Bit]
+    float256 = np.floating[_256Bit]
+    complex160 = np.complexfloating[_80Bit, _80Bit]
+    complex192 = np.complexfloating[_96Bit, _96Bit]
+    complex256 = np.complexfloating[_128Bit, _128Bit]
+    complex512 = np.complexfloating[_256Bit, _256Bit]
+else:
+    uint128 = NotImplemented
+    uint256 = NotImplemented
+    int128 = NotImplemented
+    int256 = NotImplemented
+    float80 = NotImplemented
+    float96 = NotImplemented
+    float128 = NotImplemented
+    float256 = NotImplemented
+    complex160 = NotImplemented
+    complex192 = NotImplemented
+    complex256 = NotImplemented
+    complex512 = NotImplemented