Re: Command Languages Versus Programming Languages

On Fri, 22 Nov 2024 18:18:04 -0000 (UTC)
Kaz Kylheku <643-408-1753@kylheku.com> gabbled:

On 2024-11-22, Muttley@DastartdlyHQ.org <Muttley@DastartdlyHQ.org> wrote:

Its not that simple I'm afraid since comments can be commented out.

>
Umm, no.

Umm, yes, they can.

eg:
>
   // int i; /*

>
This /* sequence is inside a // comment, and so the machinery that
recognizes /* as the start of a comment would never see it.

Yes, thats kind of the point. You seem to be arguing against yourself.

A C99 and C++ compiler would see "int j" and compile it, a regex would
simply remove everything from the first /* to */.

>
No, it won't, because that's not how regexes are used in a lexical

Yes, it will.

Also the same probably applies to #ifdef's.

>
Lexically analyzing C requires implementing the translation phases
as described in the standard. There are preprocessor phases which
delimit the input into preprocessor tokens (pp-tokens). Comments
are stripped in preprocessing. But logical lines (backslash
continuations) are recognized below comments; i.e. this is one
comment:

Not sure what your point is. A regex cannot be used to parse C comments because
its doesn't know C/C++ grammar.