Optimized Unicode.simpleFold() … #101
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…se-case. VisualVM no more sees it with this change.
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Very sorry for the delay in this review. Since UnicodeTables.java is generated, the changes to that file should be implemented by modifying the make_unicode_tables.awk script.
I think it might be worth writing the unicode tables generator in Java, I'm going to have a stab at that right now.
This change does give a nice speedup in compilation and matching, probably worth the 35kb sparse array that it creates.
alandonovan
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There's no need to rewrite the generator script. The necessary change can easily be made to the awk script.
| {0x212A, 0x004B}, | ||
| {0x212B, 0x00C5}, | ||
| }; | ||
| final char[] result = new char[tmp[tmp.length - 1][0] + 1]; |
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A comment is necessary here.
// Precompute the case folding mapping to avoid binary search at run time.
// The 'result' array maps each cased char to the next char in its orbit.
// The orbit is a cycle such as k -> K -> K [Kelvin] -> k.
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No need to rewrite it to support this change, but it could definitely use rewriting. I have a prototype that uses ICU4J to emit the same information. |
This implements the approach taken by @mykeul in google#101. Instead of a dense array of (codepoint, case-folded codepoint) mappings, CASE_ORBIT becomes a sparse array whose indices represent the key in this map.
This implements the approach taken by @mykeul in google#101. Instead of a dense array of (codepoint, case-folded codepoint) mappings, CASE_ORBIT becomes a sparse array whose indices represent the key in this map. The previous pull request was written before UnicodeTablesGenerator existed.
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Thank you, I implemented the same approach with the new UnicodeTablesGenerator in #114 |
… which was the hot spot (35.8%) in my use-case. VisualVM no more sees it with this change.