Fast(er) regular expression engines in Ruby
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Fast(er) regular expression engines in Ruby
1–7 of 7 posts
Re: Fast(er) regular expression engines in Ruby
#2Eww, pretending to support utf8 matchers while not supporting them at all was not pretty to see.
Re: Fast(er) regular expression engines in Ruby
#3Honestly that part bugs me, fake support is worse than no support imo
Re: Fast(er) regular expression engines in Ruby
#4> Another nuance was found in ruby, which cannot scan the haystack with invalid UTF-8 byte sequences.
This is extremely basic ruby: UTF-8 encoded strings must be valid UTF-8. This is not unique to ruby. If I recall correctly, python 3 does the same thing.
2.7.1 :001 > haystack = "\xfc\xa1\xa1\xa1\xa1\xa1abc"
2.7.1 :003 > haystack.force_encoding "ASCII-8BIT"
=> "\xFC\xA1\xA1\xA1\xA1\xA1abc"
2.7.1 :004 > haystack.scan(/.+/)
=> ["\xFC\xA1\xA1\xA1\xA1\xA1abc"]
Re: Fast(er) regular expression engines in Ruby
#5> Another nuance was found in ruby, which cannot scan the haystack with invalid UTF-8 byte sequences. This is extremely basic ruby: UTF-8 encoded strings must be valid UTF-8. This is not unique to ruby. If I recall correctly, python 3 does the same thing. 2.7.1 :001 > haystack = "\xfc\xa1\xa1\xa1\xa1\xa1abc" 2.7.1 :003 > haystack.force_encoding "ASCII-8BIT" => "\xFC\xA1\xA1\xA1\xA1\xA1abc" 2.7.1 :004 > haystack.scan(…
The nuance is specifically relevant here because neither of the other two regex engines benchmarked have this requirement. It's doubly relevant because that means running a regex search doesn't require a UTF-8 validation step, and is therefore likely beneficial from a perf perspective, dependening on the workload.
Re: Fast(er) regular expression engines in Ruby
#6> Another nuance was found in ruby, which cannot scan the haystack with invalid UTF-8 byte sequences. This is extremely basic ruby: UTF-8 encoded strings must be valid UTF-8. This is not unique to ruby. If I recall correctly, python 3 does the same thing. 2.7.1 :001 > haystack = "\xfc\xa1\xa1\xa1\xa1\xa1abc" 2.7.1 :003 > haystack.force_encoding "ASCII-8BIT" => "\xFC\xA1\xA1\xA1\xA1\xA1abc" 2.7.1 :004 > haystack.scan(…
The nuance is specifically relevant here because neither of the other two regex engines benchmarked have this requirement. It's doubly relevant because that means running a regex search doesn't require a UTF-8 validation step, and is therefore likely beneficial from a perf perspective, dependening on the workload.
That’s a good point. I hadn’t considered it because I’ve hit the validation error long before getting to search. It is possible to avoid string operations with careful coding prior to the search.
Edit: After a little testing, the strings can be read from and written to files without triggering validation. Presumably this applies to sockets as well.
Re: Fast(er) regular expression engines in Ruby
#7I wonder how std.regex of dlang would fare in such test. Sadly due to a tiny bit of D’s GC use it’s hard to provide as a library for other languages. If there is an interest I might take it through the tests.