PEP? context overloading: if wants(type): ...
tjreedy at home.com
Mon Aug 6 15:27:24 CEST 2001
"Jim Dennis" <jimd at vega.starshine.org> wrote in message
news:9klgl0$1frt$1 at news.idiom.com...
> I'd propose, if I felt qualified to do so, to offer a "wants()"
> or builtin that would allow a method to determine the desired
> return type or "context" of an invocation.
> So the use could look like:
> import types
> if wants(IntType):
> return n
> elif wants(TupleType):
> return (n1,n2)
> elif wants(StringType):
> return `n`
> elif wants(VoidType): # NoneType?
> What am I missing about this? What would it hurt?
a = fun(xxx) # what does a 'want'?
Without declaring types for *names* (as opposed to objects) question
On the other hand, Python type objects can be passed as function
arguments to specify a return type, so no special mechanism is needed.
def f(x, typ):
if typ == LongType: return glong(x)
elif typ == FloatType: return gfloat(x)
else return None
Terry J. Reedy
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