Comment Syntax
Rex Jaeschke
rex at aussie.COM
Sat Nov 10 11:51:50 AEST 1990
> In article <HAGERMAN.90Nov7193212 at rx7.ece.cmu.edu> hagerman at ece.cmu.edu (John Hagerman) writes:
> >Why didn't // ... newline comments make it into ANSI C?
>
Let me suggest that you CANNOT add // comments to an ANSI C compiler
WITHOUT some hacking. Consider the following example:
int i; // this comment ends in a backslash \
int j;
f()
{
i = j; /* error: j is not declared */
}
ANSI's phases of translation require that backslash/new-lines be
processed BEFORE comments. In this case the 2 declaration lines would
become:
int i; // this comment ends in a backslash int j;
and the declaration of j would be treated as part of the comment.
So, for a future version of ANSI C to adopt //, they would have to
either rearrange the phases of translation (unlikely since that would
no longer be backwards compatible) or to treat // and /**/ comments
differently and add a new phase for //.
Rex
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