sorry. still in dark.
what exactly does '/START_KEYWORD/.../END_KEYWORD/' mean?
I see a regex -> /START_KEYWORD/
an ellipsis -> ...
and a regex -> /END_KEYWORD/
you are saying the whole thing means something, but I don't understand
what.
you say 'the elipsis returns false'
what does that mean? what is it able to match? and why?
On Saturday, March 30, 2002, at 10:23 AM, Jenda Krynicky wrote:
> From: bob ackerman <[EMAIL PROTECTED]>
>
>> i don't understand your answer. how will that match anything?
>> the first line matches the whole block ok, but then the match is
>> dropped by the '!' phrases since they are in the text. also, where is
>> documented the ellipsis in a grep? also, using two regexes on either
>> side of the ellipsis?
>
> I am not using two regexps on one site of the ellipsis.
>
> If I add braces into the code you'll get this:
>
> grep { ( /START_KEYWORD/.../END_KEYWORD/ )
> and ( !/START_KEYWORD/ )
> and ( !/END_KEYWORD/} )
>
> Let's "interpret" the code in mind.
> We have
>
> @data = ( "some header",
> "some more unimportant stuff",
> "START_KEYWORD",
> "here's the text we want",
> "and here some more",
> "END_KEYWORD",
> "and again some boring stuff"
> );
>
>
> @filtered = grep { ( /START_KEYWORD/.../END_KEYWORD/ )
> and ( !/START_KEYWORD/ )
> and ( !/END_KEYWORD/ ) } @data;
>
> So first Perl processes the first item ("some header") : the elipsis
> returns false, the other conditions are not even tried, item is not
> accepted.
>
> Second item ("some more unimportant stuff") : again the same,
> ellipsis is false => item is not accepted.
>
> Third item ("START_KEYWORD") : ellipsis matches, returns true
> and switches to the second state (that is it'll return true until it
> matches the END_KEYWORD), but the second condition returns
> false so the item is not accepted.
>
> Fourth item ("here's the text we want") : the item doesn't match the
> "ending condition" of the elipsis so the ellipsis still returns true, the
> other two conditions also return true (keep in mind that the regexps
> are negated!) => item is accepted.
>
> Fifth item : same as fourth
>
> Sixth item ("END_KEYWORD") : the "end condition" of the ellipsis
> matches, ellipis returns true but switches to the first (false) state,
> the second condition returns true, but the third condition returns
> false => item is not accepted.
>
> ....
>
> Jenda
>
>
> =========== [EMAIL PROTECTED] == http://Jenda.Krynicky.cz ==========
> There is a reason for living. There must be. I've seen it somewhere.
> It's just that in the mess on my table ... and in my brain
> I can't find it.
> --- me
>
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