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Re: Regex weirdness

"Todd O'Bryan" <email@hidden> wrote:

>Strangely, if tag = "<br/>"
>
>tag.replaceAll("(?<!<b/?|<br/?)>", "&gt;") is "<br/&gt;"
>
>but
>
>tag.replaceAll("(?<!<br/?|<b/?)>", "&gt;") is "<br/>"
>
>Can someone confirm that (a) this actually happens, and that (b) it's a bug
>and there's not some reason first regex should match while the second
>doesn't?

Can you explain why you think it's a bug?

If I understand regex correctly, and it's quite possible I don't in this
case, the differences in outcome are a consequence of the short-circuit |
operator and the order of the matching expressions. The first one to match
defines the extent of the non-capturing group.

Even in a little method, I wouldn't use regex replacement for doing *ML
tag-munging. I think it would be simpler to have a dictionary of tags,
which don't suffer replacement, and then walk through the text. The
immediate evidence suggests it would be more robust, comprehensible, and
maintainable, too.

-- GG
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