Goto (Posting On Python-List Prohibited)

[Chris Angelico]

On Sun, Dec 31, 2017 at 9:43 AM, bartc <bc at freeuk.com> wrote:
> On 30/12/2017 20:36, Ben Bacarisse wrote:
>>
>> bartc <bc at freeuk.com> writes:
>>
>>> On 30/12/2017 16:53, mm0fmf wrote:
>>>>
>>>> On 30/12/2017 14:41, bartc wrote:
>>>>>
>>>>> it looks a bit naff
>>>>
>>>>
>>>> Understatement of 2017.
>>>
>>>
>>> I'm honest about my own ideas, but my remarks were about the use of
>>> special symbols such as "::" and "@".
>>>
>>> Before completely dismissing it however, you should look at how
>>> another language such as Python can achieve the same thing.
>>>
>>> Namely, take any block of code within a function, and allow it to be
>>> executed or shared from anywhere else in the function, with the
>>> minimum of disruption.
>>
>>
>> That's what a local function does and it does it with the clean
>> semantics of a function call.
>>
>> When this idea came up in comp.lang.c you could not see the point, yet
>> you appear to have a use-case common enough that you have a solution
>> worked out using gotos.
>
>
> C doesn't in general have local functions. My own languages don't implement
> them properly. So I tend not to use them.
>
>>> If it looks better than what I'd come up with, then I'll use that
>>> instead.
>>
>>
>> What looks better is always going to be an unreliable and subjective
>> measure, but calling a named function almost certainly scales better and
>> will allow for better structuring (such as when one block needs to use
>> another one).
>
>
> Using a local (or even non-local) function is what I'm trying to avoid, as I
> prefer to keep the code inline, and not disrupt it too much.
>
> You may also want to execute a block only temporarily, or as part of a short
> test. So you don't want to go to the trouble of hoisting a block of code
> into a local function.
>
> (And in C, which has local block scopes, there would be trouble with
> visibility of all the variables the block uses, unless the local function is
> untidily placed right where the original block was.)
>

Okay, so a low level language lacks certain facilities. Great. What
has this to do with Python and goto? You *can* use nested functions.
And they can do everything you need of these sub-blocks (albeit with
some overhead).

ChrisA