SyntaxEdit and regular expressions and lookaround support

Albert Wiersch

A customer was asking about lookahead support when searching with regular expressions.

It seems that positive lookahead is supported as in q(?=u) to match a "q" that is followed by a "u".

However, negative lookahead as in q(?!u), positive lookbehind as in (?<=u)q, and negative lookbehind as in (?<!u)q are not supported and throw expression parsing errors.

Is this a limitation of the regular expression engine in SyntaxEdit? If so then can lookaround support be improved?

More: http://www.regular-expressions.info/lookaround.html

Thanks!

Eugene Balabuev (LMD)

Most probably, this is quite hard to implement, and so, I can't promise it.

Albert Wiersch

I think the easiest and most useful addition, since you already have positive lookahead, would be negative lookahead. So it would be nice if at least negative lookahead could be implemented. The others are not as important.

Also, out of the recent issues I've reported, this is probably the least important yet the hardest to implement so I would like to see the other issues I reported have the highest priority.

Thanks!