RustPython · youknowone · Feb 20, 2025 · Feb 6, 2025 · Feb 20, 2025 · Feb 20, 2025
diff --git a/Lib/test/ieee754.txt b/Lib/test/ieee754.txt
@@ -0,0 +1,183 @@
+======================================
+Python IEEE 754 floating point support
+======================================
+
+>>> from sys import float_info as FI
+>>> from math import *
+>>> PI = pi
+>>> E = e
+
+You must never compare two floats with == because you are not going to get
+what you expect. We treat two floats as equal if the difference between them
+is small than epsilon.
+>>> EPS = 1E-15
+>>> def equal(x, y
8000
):
+...     """Almost equal helper for floats"""
+...     return abs(x - y) < EPS
+
+
+NaNs and INFs
+=============
+
+In Python 2.6 and newer NaNs (not a number) and infinity can be constructed
+from the strings 'inf' and 'nan'.
+
+>>> INF = float('inf')
+>>> NINF = float('-inf')
+>>> NAN = float('nan')
+
+>>> INF
+inf
+>>> NINF
+-inf
+>>> NAN
+nan
+
+The math module's ``isnan`` and ``isinf`` functions can be used to detect INF
+and NAN:
+>>> isinf(INF), isinf(NINF), isnan(NAN)
+(True, True, True)
+>>> INF == -NINF
+True
+
+Infinity
+--------
+
+Ambiguous operations like ``0 * inf`` or ``inf - inf`` result in NaN.
+>>> INF * 0
+nan
+>>> INF - INF
+nan
+>>> INF / INF
+nan
+
+However unambiguous operations with inf return inf:
+>>> INF * INF
+inf
+>>> 1.5 * INF
+inf
+>>> 0.5 * INF
+inf
+>>> INF / 1000
+inf
+
+Not a Number
+------------
+
+NaNs are never equal to another number, even itself
+>>> NAN == NAN
+False
+>>> NAN < 0
+False
+>>> NAN >= 0
+False
+
 All operations involving a NaN return a NaN except for nan**0 and 1**nan.
+>>> 1 + NAN
+nan
+>>> 1 * NAN
+nan
+>>> 0 * NAN
+nan
+>>> 1 ** NAN
+1.0
+>>> NAN ** 0
+1.0
+>>> 0 ** NAN
+nan
+>>> (1.0 + FI.epsilon) * NAN
+nan
+
+Misc Functions
+==============
+
+The power of 1 raised to x is always 1.0, even for special values like 0,
+infinity and NaN.
+
+>>> pow(1, 0)
+1.0
+>>> pow(1, INF)
+1.0
+>>> pow(1, -INF)
+1.0
+>>> pow(1, NAN)
+1.0
+
+The power of 0 raised to x is defined as 0, if x is positive. Negative
+finite values are a domain error or zero division error and NaN result in a
+silent NaN.
+
+>>> pow(0, 0)
+1.0
+>>> pow(0, INF)
+0.0
+>>> pow(0, -INF)
+inf
+>>> 0 ** -1
+Traceback (most recent call last):
+...
+ZeroDivisionError: 0.0 cannot be raised to a negative power
+>>> pow(0, NAN)
+nan
+
+
+Trigonometric Functions
+=======================
+
+>>> sin(INF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> sin(NINF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> sin(NAN)
+nan
+>>> cos(INF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> cos(NINF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> cos(NAN)
+nan
+>>> tan(INF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> tan(NINF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> tan(NAN)
+nan
+
+Neither pi nor tan are exact, but you can assume that tan(pi/2) is a large value
+and tan(pi) is a very small value:
+>>> tan(PI/2) > 1E10
+True
+>>> -tan(-PI/2) > 1E10
+True
+>>> tan(PI) < 1E-15
+True
+
+>>> asin(NAN), acos(NAN), atan(NAN)
+(nan, nan, nan)
+>>> asin(INF), asin(NINF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> acos(INF), acos(NINF)
+Traceback (most recent call last):
+...
+ValueError: math domain error
+>>> equal(atan(INF), PI/2), equal(atan(NINF), -PI/2)
+(True, True)
+
+
+Hyberbolic Functions
+====================
+