Re: Non-capturing expressions

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Yes. It's one fo the things I strongly dislike of some of the semantics of postgres ( and others ) regular engine functions. Their return value ''semantics''  depends on data, which makes them difficult to use properly when the pattern argument is unknown. I would prefer to have it always return a list with the full match in the first element, the grouped captures behind it ( i.e., {gr} for '(?:g)r', {gr,g} for '(g)r' . But I think it's dessigned more for interactive use with constant patterns than for programmatic use. 

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