utf8proc
view README @ 17:47b467f4c128
Contribution from libmojibake fork (missing file "normtest.c")
| author | Jiahao Chen, Steven G. Johnson, Anthony David Kelman |
|---|---|
| date | Mon Dec 01 14:32:19 2014 -0500 (2014-12-01) |
| parents | 00d2bcbdc945 |
| children |
line source
2 Please read the LICENSE file, which is shipping with this software.
5 *** QUICK START ***
7 For compilation of the C library call "make c-library", for compilation of
8 the ruby library call "make ruby-library" and for compilation of the
9 PostgreSQL extension call "make pgsql-library".
11 For ruby you can also create a gem-file by calling "make ruby-gem".
13 "make all" can be used to build everything, but both ruby and PostgreSQL
14 installations are required in this case.
17 *** GENERAL INFORMATION ***
19 The C library is found in this directory after successful compilation and
20 is named "libutf8proc.a" and "libutf8proc.so". The ruby library consists of
21 the files "utf8proc.rb" and "utf8proc_native.so", which are found in the
22 subdirectory "ruby/". If you chose to create a gem-file it is placed in the
23 "ruby/gem" directory. The PostgreSQL extension is named "utf8proc_pgsql.so"
24 and resides in the "pgsql/" directory.
26 Both the ruby library and the PostgreSQL extension are built as stand-alone
27 libraries and are therefore not dependent the dynamic version of the
28 C library files, but this behaviour might change in future releases.
30 The Unicode version being supported is 5.0.0.
31 Note: Version 4.1.0 of Unicode Standard Annex #29 was used, as
32 version 5.0.0 had not been available at the time of implementation.
34 For Unicode normalizations, the following options have to be used:
35 Normalization Form C: STABLE, COMPOSE
36 Normalization Form D: STABLE, DECOMPOSE
37 Normalization Form KC: STABLE, COMPOSE, COMPAT
38 Normalization Form KD: STABLE, DECOMPOSE, COMPAT
41 *** C LIBRARY ***
43 The documentation for the C library is found in the utf8proc.h header file.
44 "utf8proc_map" is most likely function you will be using for mapping UTF-8
45 strings, unless you want to allocate memory yourself.
48 *** RUBY API ***
50 The ruby library adds the methods "utf8map" and "utf8map!" to the String
51 class, and the method "utf8" to the Integer class.
53 The String#utf8map method does the same as the "utf8proc_map" C function.
54 Options for the mapping procedure are passed as symbols, i.e:
55 "Hello".utf8map(:casefold) => "hello"
57 The descriptions of all options are found in the C header file
58 "utf8proc.h". Please notice that the according symbols in ruby are all
59 lowercase.
61 String#utf8map! is the destructive function in the meaning that the string
62 is replaced by the result.
64 There are shortcuts for the 4 normalization forms specified by Unicode:
65 String#utf8nfd, String#utf8nfd!,
66 String#utf8nfc, String#utf8nfc!,
67 String#utf8nfkd, String#utf8nfkd!,
68 String#utf8nfkc, String#utf8nfkc!
70 The method Integer#utf8 returns a UTF-8 string, which is containing the
71 unicode char given by the code point.
72 0x000A.utf8 => "\n"
73 0x2028.utf8 => "\342\200\250"
76 *** POSTGRESQL API ***
78 For PostgreSQL there are two SQL functions supplied named "unifold" and
79 "unistrip". These functions function can be used to prepare index fields in
80 order to be folded in a way where string-comparisons make more sense, e.g.
81 where "bathtub" == "bath<soft hyphen>tub"
82 or "Hello World" == "hello world".
84 CREATE TABLE people (
85 id serial8 primary key,
86 name text,
87 CHECK (unifold(name) NOTNULL)
88 );
89 CREATE INDEX name_idx ON people (unifold(name));
90 SELECT * FROM people WHERE unifold(name) = unifold('John Doe');
92 The function "unistrip" removes character marks like accents or diaeresis,
93 while "unifold" keeps then.
95 NOTICE: The outputs of the function can change between releases, as
96 utf8proc does not follow a versioning stability policy. You have to
97 rebuild your database indicies, if you upgrade to a newer version
98 of utf8proc.
101 *** TODO ***
103 - detect stable code points and process segments independently in order to
104 save memory
105 - do a quick check before normalizing strings to optimize speed
106 - support stream processing
109 *** CONTACT ***
111 If you find any bugs or experience difficulties in compiling this software,
112 please contact us:
114 Project page: http://www.public-software-group.org/utf8proc