File size: 1,554 Bytes
70e8ba6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | #!/usr/bin/env python3
"""Every rate write is a receipt. Stdlib only."""
from __future__ import annotations
from fractions import Fraction as F
def as_exact(x):
if isinstance(x, bool):
raise TypeError("theta bool")
if isinstance(x, int):
return F(x)
if isinstance(x, F):
return F(x)
raise TypeError("theta not Q: %s" % type(x).__name__)
def isolate(v, seed):
v, seed = as_exact(v), as_exact(seed)
if seed == 0:
raise ValueError("theta seed 0")
return (v, seed)
def mix(a, b):
(v, r), (w, s) = a, b
return (v * w, r * w + v * s)
def rate(top, bot):
if bot[1] == 0:
raise ValueError("theta dead isolator")
return top[1] / bot[1]
def receipt(fn, v, seeds=(1, 2, F(1, 2), -1)):
"""One row per seed, plus gauge (all rates equal or split)."""
if not seeds:
raise ValueError("theta empty seeds")
rows = []
for s in seeds:
x = isolate(v, s)
y = fn(x)
r = rate(y, x)
rows.append({"seed": s, "value": y[0], "channel": y[1], "rate": r})
rates = [row["rate"] for row in rows]
gauge = all(r == rates[0] for r in rates)
return {"at": as_exact(v), "gauge": gauge, "rate": rates[0] if gauge else None, "rows": rows, "theta": not gauge}
if __name__ == "__main__":
sq = lambda x: mix(x, x)
rec = receipt(sq, 3)
print("gauge", rec["gauge"], "rate", rec["rate"])
for row in rec["rows"]:
print(row)
try:
receipt(sq, 3, seeds=())
except ValueError as e:
print(e)
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