Bengt Richter wrote:
On Thu, 30 Dec 2004 15:15:51 -0800, Jeff Shannon <[EMAIL PROTECTED]> wrote:
Mimicking function-def indentation inside of another function's arglist strikes me as an abomination just waiting to happen; in comparison, the need to type a name twice seems trivial.
Self-restraint can avoid abominations ;-)
It can, but given the prevalence of lambda abominations (such as the many that the Martellibot described among Cookbook submissions), is there any reason to believe that there would be *more* restraint in using a less-constrained feature?? :)
As a result, it seems to me that, rather than generalize lambdas into "full" anonymous functions (with most of the negatives and few of the positives of lambda), it would be much better to specialize them further into inline-closure-creators, where they can serve a valuable purpose without quite as much risk of code pollution.
(BTW, again, by closure, do you really mean deferred-action-thingie?)
My understanding of "closure" (which may well be wrong, as I've inferred it entirely from past discussions on this newsgroup) is that it's a callable with some or all of its parameters already set; e.g.,
def one_and(foo):
def closure(arg):
return foo(1, arg)
return closureincr = one_and(operator.add)
The function one_and() returns a closure, here bound to incr. It is essentially a (partially) deferred action thingy, if you want to use technical terms. ;) I suppose that one could look at it as the environment in which to call a given function, exported for later use...
My thesis here is that one of the most common (legitimate) uses of lambda is as an adapter, to create an intermediary that allows a callable with a given signature to be used in places where a different signature is expected -- that is, altering the number or order of arguments passed to a given callable (and possibly also capturing the current value of some other variable in the process). I feel that it's more fruitful to focus on this "adapter" quality rather than focusing on the "anonymous function" quality.
Jeff Shannon Technician/Programmer Credit International
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