in reply to alternation in regexes: to use or to avoid?
The amount of time the regex takes to execute is insignificant in the long run. What matters is how much I/O the program does or doesn't do, and that includes virtual-memory. Process the data in reasonably sized chunks, applying whatever you might know about which test is most likely to succeed first. Make the whole thing easy to maintain. Don't sweat nanoseconds when it's milliseconds that matter.
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