On Thu, 09 Feb 2006 16:41:10 +1300, Greg Ewing <[EMAIL PROTECTED]> wrote:
>My thought on lambda at the moment is that it's too VERBOSE.
>
>If a syntax for anonymous functions is to pull its weight,
>it needs to be *very* concise. The only time I ever consider
>writing a function definition in-line is when the body is
>extremely short, otherwise it's clearer to use a def instead.
>
>Given that, I do *not* have the space to waste with 6 or 7
>characters of geeky noise-word.
OTOH, it does stand out as a flag to indicate what is being done.
>
>So my vote for Py3k is to either
>
>1) Replace lambda args: value with
>
> args -> value
>
>or something equivalently concise, or
>
Yet another bike shed color chip:
!(args:expr) # <==> lambda args:expr
and
!(args::suite) # <==> (lambda args::suite)
(where the latter lambda form requires outer enclosing parens) But either "::"
form
allows full def suite, with indentation for multilines having left edge of
single indent
defined by first line following the "::"-containing line, and explicit returns
for values
required and top suite ending on closing outer paren)
Probable uses for the "::" form would be for short inline suite definitions
!(x::print x) # <==> (lambda x::print x) & etc. similarly
!(::global_counter+=1;return global_counter)
!(::raise StopIteration)() # more honest than iter([]).next()
but the flexibility would be there for an in-context definition, e.g.,
sorted(seq, key= !(x::
try: return abs(x)
except TypeError: return 0))
and closures could be spelled
!(c0,c1:!(x:c0+c1*x))(3,5) # single use with constants is silly spelling
of !(x:3+5*x)
Hm, are the latter two really better for eliminating "lambda"? Cf:
sorted(seq, key=(lambda x::
try:return abs(x)
except TypeError: return 0))
and
(lambda c1,c2:lambda x:c0+c1*x)(3,5) # also silly with constants
I'm not sure. I think I kind of like lambda args:expr and (lambda args::suite)
but sometimes super-concise is nice ;-)
>2) Remove lambda entirely.
>
-1
Regards,
Bengt Richter
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