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@NogDogJul 29.2005 — #OK, my brain is too foggy today to figure out that whole thing, but I'm pretty sure at least part of the problem is attempting to use "[ ]" to do more than they can. The only thing that should be between a pair of square brackets (a "character class definition") is a list of characters, optionally preceded by a negation symbol ("^"). All the characters within (and there are shortcuts for certain groups of characters or ranges of characters) are used to establish a match for precisely one character in the searched string which falls within the set of characters defined by that character class.
Therefore, there is no nesting of character classes, nor groupings with "( )", etc., as all you are able to match is one character within the class being defined.
So, what is the solution? That, my friend, probably needs more thought than my brain is capable of performing right now.
I’ve got a regexp problem and I suck too much to be able figure out how to fix it.
Hi folks. A while ago I was trying to put together a text processing class and was lucky enough to be graced by the assistance of the all knowing NogDog. It came in the form of a regexp that (at the time) fulfilled my requirements perfectly. My requirements on some filters however, has expanded a little and I’ve developed it a bit based on what NogDog started me with. After about a day of driving myself mad trying to isolate the problem, I’ve finally found why it keeps going wrong. The only problem is, I don’t know how to fix it.
Here’s the expression I’m having problems with:
[code]
“/b”.$linkstock[0].”b(?!(([^<]*>)|([^([{)]*(}]))|([^([{link( )?to=”([^”rn]*)”( )?is=”([^”rn]*)”}])]*([{/link}]))))/i”
And here’s a slightly more readable breakdown of it:
[code]
“/
b”.
$linkstock[0].
“b
(?!
(
([^<]*>)
|
([^([{)]*(}]))
|
(
[^
(
[{
link
( )?
to=”
([^”rn]*)
”
( )?
is=”
([^”rn]*)
”
}]
)
]
*
([{/link}])
)
)
)
/i”
The problem comes in the latter section. It is caused by these inverted sets:
[code]
([^”rn]*)
On their own, they’re fine, but the problem is, if you look a little earlier on than those sets, you’ll see that they themselves are inside an inverted set. That is where my problem lies. PHP5 says:
[quote]
Warning: preg_replace() [function.preg-replace]: Compilation failed: unmatched parentheses
I would imagine most folks that are reasonably familiar with regexp will be able to understand what I inted the express, I just don’t know how to without nesting those inverted sets. ?
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@NogDogJul 29.2005 — #OK, my brain is too foggy today to figure out that whole thing, but I'm pretty sure at least part of the problem is attempting to use "[ ]" to do more than they can. The only thing that should be between a pair of square brackets (a "character class definition") is a list of characters, optionally preceded by a negation symbol ("^"). All the characters within (and there are shortcuts for certain groups of characters or ranges of characters) are used to establish a match for precisely one character in the searched string which falls within the set of characters defined by that character class.Therefore, there is no nesting of character classes, nor groupings with "( )", etc., as all you are able to match is one character within the class being defined.
So, what is the solution? That, my friend, probably needs more thought than my brain is capable of performing right now.