[Python-ideas] Definition Symmetry

[Ned Batchelder]

On 2/1/2013 12:21 AM, Jason Keene wrote:
> Both class and function definitions produce callable objects that are 
> assigned to a name with nearly identical syntax. I don't think your 
> analogy with import/break statements is valid.  Additionally, both 
> definitions produce very similar byte codes:
>
>               3 MAKE_FUNCTION            0
>               6 STORE_FAST               0 (my_func)
>
>               9 MAKE_FUNCTION            0
>              12 CALL_FUNCTION            0
>              15 BUILD_CLASS
>              16 STORE_FAST               0 (MyClass)
>
> The only argument I see for requiring empty parens in function 
> definitions is a historical one.

That's because you're ignoring the main one:  function calls require 
parens, so function definitions also require them.

--Ned.

>
> On Thursday, January 31, 2013, Ben Finney wrote:
>
>     Jason Keene <jasonkeene at gmail.com <javascript:;>> writes:
>
>     > In a way they do the same thing, they both create an object
>     > (function/class) from a suite and assign it to the name given
>     after the
>     > keyword (def/class).  Sure they do totally different things with
>     the suite
>     > in creating the object, but in essence it's a name assignment.
>
>     In a way, 'import' and 'break' do the same thing, they trigger the
>     compiler to compile a particular set of code bytes. Sure the code
>     bytes
>     do totally different things, but in essence it's a statement.
>
>     Less facetiously: You can blur your vision as much as you like to make
>     'class' and 'def' look similar, but that doesn't diminish the
>     importance
>     of the distinctions you're ignoring.
>
>     --
>      \       "Always do right. This will gratify some people, and
>     astonish |
>       `\                                            the rest." ---Mark
>     Twain |
>     _o__)                |
>     Ben Finney
>
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