<regex>: Fix word bounds \b and \B when applied to the empty string
#5375
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StephanTLavavej
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StephanTLavavej
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Apr 1, 2025
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Thanks for the fix, test coverage, and clear writeup with citations! I pushed a trivial change to use raw string literals. |
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Fixes #5371.
The ECMAScript standard effectively states that
\bmatches a positioniin the string iffIsWordChar(i-1) xor IsWordChar(i)is true. It also defines that for positionsi = -1andi = length(input),IsWordChar(i)always returnsfalse. Thus,\bdoes not match anything in the empty string.Since
\bdoes not match the empty string, the flagsmatch_not_bowandmatch_not_eowdon't matter in this case.