dataflow.py

inf = float("+inf")

def fix(bottom, n=inf, unwrap=lambda x: x): if not callable(bottom): bottom_value = bottom bottom = lambda *args: bottom_value def decorator(f): def f_fix(*args): me = (f_fix, args) if not fix.calling: value, fix.values[me] = None, bottom(*args) i = 0 while i < n and value != fix.values[me]: fix.calling.add(me) value, fix.values[me] = fix.values[me], unwrap(f(*args)) fix.calling.clear() i += 1 return value if me in fix.calling: return fix.values.get(me, bottom(*args)) fix.calling.add(me) value = fix.values[me] = unwrap(f(*args)) fix.calling.remove(me) return value return f_fix return decorator

fix.calling = set() fix.values = {}