[Python-Dev] any support for a methodcaller HOF? (original) (raw)

Bengt Richter bokr at oz.net
Fri Feb 3 21:58:06 CET 2006

On Fri, 03 Feb 2006 19:10:42 +0100, Christian Tismer <tismer at stackless.com> wrote:

Bengt Richter wrote:

...

BTW, re def-time bindings, the default arg abuse is a hack, so I would like to see a syntax that would permit default-arg-like def-time function-local bindings without affecting the call signature. E.g., if def foo(*args, **keywords, ***bindings): ... would use bindings as a dict at def-time to create local namespace bindings like **keywords, but not affecting the call signature. This would allow a nicer version of above-mentioned lambda x, zip=zip, zop=zop:x.method(zip,zop) as lambda x, ***dict(zip=zip, zop=zop):x.method(zip,zop) or lambda x, ***{'zip':zip, 'zop':zop}:x.method(zip,zop) This could also be used to do currying without the typical cost of wrapped nested calling. Just in case that you might be not aware of it (like I was): lambda does support local scope, like here: >>> def locallambda(x, y): ... func = lambda: x+y ... return func ... >>> f=locallambda(2, 3) >>> f() 5 Yes, thanks, I really did know that ;-/ Just got thinking along another line. So lambda x, zip=zip, zop=zop:x.method(zip,zop) and lambda x, ***{'zip':zip, 'zop':zop}:x.method(zip,zop) would better have been (lambda zip,zop:lambda x:x.method(zip,zop))(zip, zop)

Regards, Bengt Richter

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