I came across this neat Python hack on reddit today, a technique for defining arbitrary infix operators. Not overriding + or >> et al., but creating keyword-style pseudo-operators that… well, the code is probably as clear as any description I could come up with:
class infix(object):
"""
Clever hack (slightly modified) for defining infix operators.
Via http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/384122
Intended for use as a decorator.
>>> @infix
... def removing(str, chars):
... for char in chars:
... str = str.replace(char, '')
... return str
...
>>> print 'Hello, world!' |removing| 'eo'
Hll, wrld!
"""
def __init__(self, function):
self.function = function
def __ror__(self, other):
return infix(lambda x: self.function(other, x))
def __or__(self, other):
return self.function(other)
def __call__(self, value1, value2):
return self.function(value1, value2)
Some people hate this kind of stuff. That’s why we call it a hack, to indicate that we don’t think it’s a great building block for your missile control software. Some of Those People still get their underoos in a bunch regardless. But you have to admit it’s damned clever.