I know I can do this with a regex, but...

[Tman]

Need to strip comments from VBScript code.

Tried to use a state machine to tell if I was in quotes, but got very
confused. I know I can use a regex, although I may have to call it
repeatedly to eat quoted strings. Anyone have ideas?

I need to whack everything after the first comment character...

this is not a comment
'this line is fully commented
the comment 'in this line starts after ' the word comment
there "is no 'comment" in this line
but in "this 'line" there 'is a "comment" before the word "is"
'this line is "fully" commented

ad infinitum...

[Anno Siegel]

Tman <nerdy1@snet.net> wrote in comp.lang.perl.misc:

> Need to strip comments from VBScript code.
>
> Tried to use a state machine to tell if I was in quotes, but got very
> confused. I know I can use a regex, although I may have to call it
> repeatedly to eat quoted strings. Anyone have ideas?
>
> I need to whack everything after the first comment character...
>
> this is not a comment
> 'this line is fully commented
> the comment 'in this line starts after ' the word comment
> there "is no 'comment" in this line
> but in "this 'line" there 'is a "comment" before the word "is"
> 'this line is "fully" commented

Take a look at Regex::Common. It has elaborate regexes that deal
with comments.

Anno

[Abigail]

Anno Siegel (anno4000@lublin.zrz.tu-berlin.de) wrote on MMMDCLXX
September MCMXCIII in <URL:news:bkbrds$o08$1@mamenchi.zrz.TU-Berlin.DE>:
^^ Tman <nerdy1@snet.net> wrote in comp.lang.perl.misc:
^^ > Need to strip comments from VBScript code.
^^ >
^^ > Tried to use a state machine to tell if I was in quotes, but got very
^^ > confused. I know I can use a regex, although I may have to call it
^^ > repeatedly to eat quoted strings. Anyone have ideas?
^^ >
^^ > I need to whack everything after the first comment character...
^^ >
^^ > this is not a comment
^^ > 'this line is fully commented
^^ > the comment 'in this line starts after ' the word comment
^^ > there "is no 'comment" in this line
^^ > but in "this 'line" there 'is a "comment" before the word "is"
^^ > 'this line is "fully" commented
^^
^^ Take a look at Regex::Common. It has elaborate regexes that deal
^^ with comments.


But Regexp::Common will only give you patterns for comments - it
doesn't include language parsers. All the patterns of Regexp::Common
are context free - but for most languages the pattern for comments
isn't context free (for instance, they can be included in literals).

Having said that, if the only concern is double quoted strings,
something like this might work (untested):

use Regexp::Common;

s [($RE{delimited}{-delim => '"'})|'.*\n]
[$1 || ""]eg;


Abigail
--
perl -weprint\<\<EOT\; -eJust -eanother -ePerl -eHacker -eEOT

[Philip Lees]

On Thu, 18 Sep 2003 02:06:53 GMT, "Tman" <nerdy1@snet.net> wrote:

>Need to strip comments from VBScript code.
>
>Tried to use a state machine to tell if I was in quotes, but got very
>confused. I know I can use a regex, although I may have to call it
>repeatedly to eat quoted strings. Anyone have ideas?
>
>I need to whack everything after the first comment character...

The Perl FAQ gives a regex for doing this kind of splitting. However,
as you're only concerned about breaking into two pieces, it might be
easier to do it this way (if you don't care about efficiency).

while (<DATA>){
chomp;
my $line = "";
foreach( split // ){
unless ( /"/ ... /"/ ){ last if /'/ }
$line .= $_
}
print "$line\n" if $line;
}

__DATA__
this is not a comment
'this line is fully commented
the comment 'in this line starts after ' the word comment
there "is no 'comment" in this line
but in "this 'line" there 'is a "comment" before the word "is"
'this line is "fully" commented

Phil

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