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javascript v8 double base36 decode/encode in python
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# this is specific to the v8 js engine | |
# firefox actually does something slightly different so their encodings are incompatible | |
import sys | |
import math | |
import string | |
from functools import reduce | |
import numpy as np | |
from numpy import float64 as f64 | |
alpha = string.digits + string.ascii_lowercase | |
# example input: ruse0iihfcd | |
# example output: 0.7737566290658499 | |
def b36_double(b36): | |
return reduce(lambda a, x: f64(alpha.index(x) + a) / 36, reversed(b36), 0) | |
# sadly python doesnt have an `unfold` so this looks a bit messy | |
def double_b36(d): | |
d = f64(d) | |
delta = f64(0.5) * (np.nextafter(d, 1) - d) | |
# if d is a smoll boi | |
delta = max(np.nextafter(f64(0), 1), delta) | |
res = '' | |
while d >= delta: | |
d *= 36 | |
delta *= 36 | |
x = math.floor(d) | |
d -= x | |
res += alpha[x] | |
return res | |
#print(double_b36(0.123456789)) | |
print(b36_double(sys.argv[1])) |
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