Bug fix + 16x speedup for -w when WORD starts with string literal #123
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…h \b\W or ending with \W\b Old code: $ sift "\b\W\W\W\b" $m/mist-ap/cloud | wc -l 0 New code: $ sift "\b\W\W\W\b" $m/mist-ap/cloud | wc -l 3509 Ripgrep agrees with bug fix: $ rg "\b\W\W\W\b" $m/mist-ap/cloud | wc -l 3509
…tches for WORD start with a string literal. 1. Make a first pass over the haystack by starting the search with the string literal part of the needle: WORD\b It's a more selective filter (in most cases) and delays entering the slower regex engine. [1] 2. Do a second pass with the now much smaller haystack on the complete needle: \bWORD\b [1] https://github.com/golang/go/blob/a064a4f29a97a4fc7398d1ac9d7c53c5ba0bc646/src/regexp/backtrack.go#L341 Observed 16x speedup for the following pattern and directory: sift -q "\bWaitForConnect\b" $m/mist-ap 2.60s user 0.09s system 549% cpu 0.488 total sift -w -q "WaitForConnect" $m/mist-ap 0.08s user 0.10s system 570% cpu 0.031 total
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