PEP 312 - Making lambdas implicit worries me, surely it's just the name 'lambda' that is bad...

[Erik Max Francis]

Alexander Schmolck wrote:

> Do you think adding a few keystrokes by replacing
> 
>  >>> a + b * c[2]
> 
> with the more explict
> 
>  >>> a operatorAddOrMaybeConcatenate (b operatorMultiplyOrMaybeRepeat 
> c
>  ...                                    operatorAtIndexOrMaybeKey 1)
> 
> would make python unusable? Or maybe just unpopular?

Just as using fewer keystrokes for its own sake is not a laudable goal,
neither is using more keystrokes for its own sake.  Since nobody's
proposed anything like the above, it's a red herring.

> (Hint: in case the point of how mere "differences in keystrokes" can
> widely
> affect design choices in a language and its libraries was lost on you;
> do you
> really think anyone would dream of introducing a ternary operator if
> you could
> just do
> 
>  def when(cond, a,b):
>      if cond: return a()
>      else: return  b()
> 
>  res = when(cond, :b, :c)
> 
> instead of
> 
>  res = when(cond, lambda : b, lambda :c)

In a word, yes, because in a conditional operator the lazy evaluation is
implicit.  You can forgot the lambdas/colons in the non-short-circuiting
version.

The point here is that terseness in and of itself is not a laudable
goal, especially for Python.  Readability is far more important to me
than terseness.  Considering that the functionality for this already
exists with the addition of _one_ extra keyword, offering the ability to
remove that lambda in the corner case of a zero-argument thunk does not
seem attractive; it makes it shorter, but it makes it less readable.  I
want Python to be more Pythonic, not more like Perl.

That Smalltalk has a particularly compact form for expressing explicit
lazy evaluation is fine for Smalltalk.  But that has no bearing on
whether Python should also have a compact form _for the sole purpose of
being compact_.  Especially since getting the same effect in Python is
so straightforward.

-- 
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