uax-15

This package provides a common lisp unicode normalization function using nfc, nfd, nfkc and nfkd as per Unicode Standard Annex #15 found at http://www.unicode.org/reports/tr15/tr15-22.html.

This is a fork of a subset of work done by Takeru Ohta in 2010. Future work is intended to provide support for https://tools.ietf.org/html/rfc8264 and https://tools.ietf.org/html/rfc7564.

Implementation Notes

This has been successfully tested on sbcl, ccl, ecl, abcl, allegro and cmucl against the unicode test file found at http://www.unicode.org/Public/UNIDATA/NormalizationTest.txt

Clisp still has some issues. It has not been tested against lispworks or other common lisp implementations.

Usage

It has one major exported function:

• (normalize (str unicode-normalization-method))

The currently supported normalization methods are :nfc :nfkc :nfd :nfkd

Normalization example with reference to relevant xkcd https://www.xkcd.com/936/

    (normalize "正しい馬バッテリーステープル" :nfkc)
    "正しい馬バッテリーステープル"

    (normalize "الحصان الصحيح البطارية التيلة" :nfkc)
    "الحصان الصحيح البطارية التيلة"

    (normalize "اstáplacha ceart ceallraí capall" :nfkc)
    "اstáplacha ceart ceallraí capall"

To Do list

• Implement and validate against https://tools.ietf.org/html/rfc8264 and https://tools.ietf.org/html/rfc7564
• Optimization?

More relevant xkcd https://xkcd.com/1726/, https://xkcd.com/1953/, https://www.xkcd.com/1209/, https://xkcd.com/1137/

Data Files

• UnicodeData.txt was downloaded from http://www.unicode.org/Public/UNIDATA/UnicodeData.txt
• The file CompositionExclusions.txt was downloaded from http://www.unicode.org/Public/UNIDATA/CompositionExclusions.txt
• The file DerivedNormalizationProps.txt was downloaded from http://www.unicode.org/Public/UNIDATA/DerivedNormalizationProps.txt
• The test file NormalizationTest.txt was downloaded from http://www.unicode.org/Public/UNIDATA/NormalizationTest.txt

Other References

• https://tools.ietf.org/html/rfc5802
• http://www.unicode.org/reports/tr15/#References
• https://www.unicode.org/reports/tr41/tr41-24.html
• https://www.unicode.org/charts/normalization/
• https://towardsdatascience.com/difference-between-nfd-nfc-nfkd-and-nfkc-explained-with-python-code-e2631f96ae6c
• https://en.wikipedia.org/wiki/Unicode_equivalence
• http://www.unicode.org/faq/normalization.html
• https://github.com/edicl/cl-unicode/blob/master/specials.lisp
• https://perldoc.perl.org/Unicode/Normalize.html
• https://www.mkssoftware.com/docs/perl/lib/Unicode/Normalize.asp
• https://github.com/Wisdom/Awesome-Unicode