Re^2: alternation in regexes: to use or to avoid?

But that doesn't leave room for the various match-words to have different "\w+"'s - e.g. /\bFOO:\s*bar(\d+)/ or /\bBAZ:\s*(\w+)/

I guess I'm wondering why the trie-optimization isn't used for fixed string prefixes as well (as I'd assumed before I wrote the code).

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Re^3: alternation in regexes: to use or to avoid? by dave_the_m (Monsignor) on Dec 10, 2012 at 19:40 UTC
Actually I stand corrected: the fixed string prefixes are collected together into a trie where there are (possibly differing) wildcard suffixes; the killer is the individual captures, which disables the trie optimisation. So, alternation is the fastest, as long as you put any captures outside the alt. Dave.	[reply]