| |
| """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) |
|
|
