# -*- coding: utf-8 -*-

from ..syntax import macros, test, test_raises, error # noqa: F401

from ..test.fixtures import session, testset

import sys

from ..numutil import almosteq, ulp

def runtests():

with testset("ulp (unit in the last place; float utility)"):

test[ulp(1.0) == sys.float_info.epsilon]

# test also at some base-2 exponent switch points

test[ulp(2.0) == 2 * sys.float_info.epsilon]

test[ulp(0.5) == 0.5 * sys.float_info.epsilon]

with testset("almosteq"):

# For anything but floating-point inputs, it's exact equality.

test[almosteq("abc", "abc")]

test[not almosteq("ab", "abc")]

test[almosteq(1.0, 1.0 + ulp(1.0))]

# TODO: counterintuitively, need a large tolerance here, because when one operand is zero,

# TODO: the final tolerance is actually tol*min_normal.

min_normal = sys.float_info.min

test[almosteq(min_normal / 2, 0, tol=1.0)]

too_large = 2**int(1e6)

test_raises[OverflowError, float(too_large), "UPDATE THIS, need a float overflow here."]

test[almosteq(too_large, too_large + 1)] # works, because 1/too_large is very small.

try:

from mpmath import mpf

except ImportError: # pragma: no cover

error["mpmath not installed in this Python, cannot test arbitrary precision input for mathseq."]

else:

test[almosteq(mpf(1.0), mpf(1.0 + ulp(1.0)))]

test[almosteq(1.0, mpf(1.0 + ulp(1.0)))]

test[almosteq(mpf(1.0), 1.0 + ulp(1.0))]

if __name__ == '__main__': # pragma: no cover

with session(__file__):

runtests()