Re: Regular expression too big

[Chong Yidong]

Greg Detre <address@hidden> writes:

>> Looks like your best/only option.  Of course you may also be able to do it
>> all in Emacs by not using regexps.  E.g. if your code looks anything like
>>
>>    (re-search-forward (concat "foo" (regexp-opt mighty-big-list) "bar"))
>>
>> you may be able to use
>>
>>    (while (and (re-search-forward (concat "foo\(.*\)bar"))
>>                (not (member (match-string 1) mighty-big-list))))
>>
>> And of course, use a hash-table rather than a list.
>
> thanks, stefan. that makes sense. but it would need to run within the
> fontification function, so we'd like it to be speedy...

The approach Stefan suggested, using a hash table, may very well be
faster than scanning for an enormous regular expression.