GOTO sentence is known as evil. I think so.
And Python has try ... except ... which works similar to GOTO sentence.
Suddenly I want to try to implement GOTO sentence like functionality in Python without using try ... except ....
Looks like below.
from functools import wraps
from contextlib import contextmanager
class AlreadyRegistered(Exception):
...
class UnknownLabel(Exception):
...
class GOTO:
goto_funcs = {}
current_label = None
def __init__(self, name=None):
self._name = name
def jump(self, label: str):
func = self.goto_funcs.get(label)
if not func:
raise UnknownLabel(label)
self.current_label = label
func()
def __call__(self, label: str):
def _inner(func):
if label not in self.goto_funcs:
self.goto_funcs[label] = func
else:
raise AlreadyRegistered(label)
@wraps(func)
def __inner(*args, **kwargs):
return func(*args, **kwargs)
return __inner
return _inner
def __str__(self):
return f'{self.__class__}: {self._name}'
if __name__ == '__main__':
goto = GOTO('mygoto')
count = 0
@goto('loop')
def loop():
global count
print(f'current count = {count}')
count += 1
if count >= 2:
return goto.jump('end')
goto.jump('loop')
@goto('end')
def end():
print('all done')
loop()
This maybe very very limited and clearly very useless!
Bye.
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