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LibRegex: Use a match table for character classes

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Generate a sorted, compressed series of ranges in a match table for
character classes, and use a binary search to find the matches.
This is about a 3-4x speedup for character class match performance. :^)
This commit is contained in:
Ali Mohammad Pur 2021-10-03 19:01:25 +03:30 • committed by Andreas Kling
parent 478b36c37b
commit 8f722302d9
6 changed files with 232 additions and 35 deletions
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18
Tests/LibRegex/Regex.cpp
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@ -910,3 +910,21 @@ TEST_CASE(optimizer_atomic_groups)
EXPECT_EQ(result.success, test.get<2>());
}
}
TEST_CASE(optimizer_char_class_lut)
{
Regex<ECMA262> re(R"([\f\n\r\t\v\u00a0\u1680\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000\ufeff]+$)");
if constexpr (REGEX_DEBUG) {
dbgln("\n");
RegexDebug regex_dbg(stderr);
regex_dbg.print_raw_bytecode(re);
regex_dbg.print_header();
regex_dbg.print_bytecode(re);
dbgln("\n");
}
// This will go through _all_ alternatives in the character class, and then fail.
for (size_t i = 0; i < 1'000'000; ++i)
EXPECT_EQ(re.match("1635488940000"sv).success, false);
}