On 23 Jan 2008, at 09:44, Aaron Brady wrote:
-----Original Message----- On 8 Oct 2007, at 10:57, Arnaud Delobelle wrote:
On Mon, October 8, 2007 4:33 am, Adam Atlas wrote:
When writing decorators especially when it's one that needs arguments other than the function to be wrapped, it often gets rather ugly...
[...]
Whhy not create a (meta-)decorator to do this? Something like: [...]
Following up post from 10/8/07.
To follow up on my untested suggestion, here's one that is tested:
# This metadecorator hasn't changed
def decorator_withargs(decf): def decorator(*args, **kwargs): def decorated(f): return decf(f, *args, **kwargs) return decorated return decorator
This is equivalent to: (1) decorator_withargs= partial( partial, prepartial )
[where partial is as in functools and prepartial(f, x, y)(z, t) <=> f(z, t, x, y)] Indeed, and if one restricts decorator_withargs to keyword arguments, one can simply define it as: decorator_withargs = partial(partial, partial) Which is the curry operator! So decorator_withargs is some sort of curry. In fact I had never realised before that this was a way to define curry (for functions with 2 arguments) curry = partial(partial, partial) [if f is a two-arguments function then curry(f)(x)(y) is f(x, y)] This means that a meta-decorator (i.e. a decorator for decorators) is a kind of currying operator.
Intriguing.
! -- Arnaud