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From: Spiros Bousbouras <spibou@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: An enhancement
Message-ID: <qwerty@bongo-ra.co>
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Xref: csiph.com comp.lang.c:136449

On Mon, 8 Oct 2018 15:44:14 -0700 (PDT)
David Kleinecke <dkleinecke@gmail.com> wrote:
> I want to propose an enhancement:
> 
> Add to C the statement type
>     DO identifier SEMICOLON
> where the identifier is a label. The meaning is that
> the statement just identified is replaced by the
> statement following the label.

[...]

> The purpose of this enhancement is to enable
> top-down coding in the sense Knuth wanted with
> his literate programming. You can write code
> like:
>     int foo (int x) {
>         if (x < 0) do trivial_case;
>         else if (x == 0) do easy_case;
>         else do usual_case;
>         return;
>      trivial_case: { 
>         .... }
>      easy_case: { 
>         .... }
>      usual_case: { 
>         .... }}
> which is generally easier to understand if you have
> given as labels good descriptive phrases.

You could achieve the same with macros :

int foo (int x) {
#define  trivial_case {  \
    ....                 \
}
#define  easy_case {     \
    ....                 \
}
#define  usual_case {    \
    ....                 \
}
    if (x < 0) trivial_case
    else if (x == 0) easy_case
    else usual_case
    return 13 ;
}

Your code looks cleaner but I'm not sure the difference is worth adding
the new syntax.