Sujet : Re: Loops (was Re: do { quit; } else { })
De : Muttley (at) *nospam* DastardlyHQ.org
Groupes : comp.lang.cDate : 23. Apr 2025, 17:00:16
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vub2qg$3eq52$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
On Wed, 23 Apr 2025 14:50:22 +0100
bart <
bc@freeuk.com> wibbled:
On 23/04/2025 11:58, Muttley@DastardlyHQ.org wrote:
On Wed, 23 Apr 2025 11:15:01 +0100
bart <bc@freeuk.com> wibbled:
IMV, macros generally are a bad idea. They are especially bad with how
they are implemented in C:
C macros do essentially 4 different things:
1) Provide a way to pass compilation data directly into the code via compiler
>
switches and #ifdef
2) Allow conditional compilation for different OS's
>
That does not need expandable macros.
It needs something so why not use macros.
3) Allow repeating blocks of code to be compacted into a single macro when
having a function instead would be more complicated and/or inefficient.
4) An alternative to inline functions. Probably the least useful.
* Their implementation is complex and poorly defined.
Maybe to you.
>
Have you ever implemented a C preprocessor?
No, have you? I've not built a smartphone either but I don't find them complex
to use.
* Macros don't obey normal scope rules.
They're not supposed to.
>
So, is that good or bad? (Let me guess: it's good that it works like that!)
Why would you want scoping with macros FFS? They need to be consistent and
available everywhere in a piece of source code.
So what? You'd get a compilation error.
>
If you're lucky. Or you get a silent, undetectable bug, since any
No, not if you're lucky - you WILL get an error with that example. Why don't
you try it instead of gassing.
alphanumeric token: identifier, type, or reserved word, gets expanded,
no matter what the context.
Yes, thats whole the fucking point. If you don't want that don't use them!
do { quit; } else { }
Re: do { quit; } else { }