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Diffstat (limited to 'contrib/unaccent/generate_unaccent_rules.py')
| -rw-r--r-- | contrib/unaccent/generate_unaccent_rules.py | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/contrib/unaccent/generate_unaccent_rules.py b/contrib/unaccent/generate_unaccent_rules.py new file mode 100644 index 00000000000..b838d8f630d --- /dev/null +++ b/contrib/unaccent/generate_unaccent_rules.py @@ -0,0 +1,123 @@ +#!/usr/bin/python +# +# This script builds unaccent.rules on standard output when given the +# contents of UnicodeData.txt[1] on standard input. Optionally includes +# ligature expansion, if --expand-ligatures is given on the command line. +# +# The approach is to use the Unicode decomposition data to identify +# precomposed codepoints that are equivalent to a ligature of several +# letters, or a base letter with any number of diacritical marks. +# There is also a small set of special cases for codepoints that we +# traditionally support even though Unicode doesn't consider them to +# be ligatures or letters with marks. +# +# [1] http://unicode.org/Public/7.0.0/ucd/UnicodeData.txt + +import re +import sys + +def print_record(codepoint, letter): + print (unichr(codepoint) + "\t" + letter).encode("UTF-8") + +class Codepoint: + def __init__(self, id, general_category, combining_ids): + self.id = id + self.general_category = general_category + self.combining_ids = combining_ids + +def is_plain_letter(codepoint): + """Return true if codepoint represents a plain ASCII letter.""" + return (codepoint.id >= ord('a') and codepoint.id <= ord('z')) or \ + (codepoint.id >= ord('A') and codepoint.id <= ord('Z')) + +def is_mark(codepoint): + """Returns true for diacritical marks (combining codepoints).""" + return codepoint.general_category in ("Mn", "Me", "Mc") + +def is_letter_with_marks(codepoint, table): + """Returns true for plain letters combined with one or more marks.""" + # See http://www.unicode.org/reports/tr44/tr44-14.html#General_Category_Values + return len(codepoint.combining_ids) > 1 and \ + is_plain_letter(table[codepoint.combining_ids[0]]) and \ + all(is_mark(table[i]) for i in codepoint.combining_ids[1:]) + +def is_letter(codepoint, table): + """Return true for letter with or without diacritical marks.""" + return is_plain_letter(codepoint) or is_letter_with_marks(codepoint, table) + +def get_plain_letter(codepoint, table): + """Return the base codepoint without marks.""" + if is_letter_with_marks(codepoint, table): + return table[codepoint.combining_ids[0]] + elif is_plain_letter(codepoint): + return codepoint + else: + raise "mu" + +def is_ligature(codepoint, table): + """Return true for letters combined with letters.""" + return all(is_letter(table[i], table) for i in codepoint.combining_ids) + +def get_plain_letters(codepoint, table): + """Return a list of plain letters from a ligature.""" + assert(is_ligature(codepoint, table)) + return [get_plain_letter(table[id], table) for id in codepoint.combining_ids] + +def main(expand_ligatures): + # http://www.unicode.org/reports/tr44/tr44-14.html#Character_Decomposition_Mappings + decomposition_type_pattern = re.compile(" *<[^>]*> *") + + table = {} + all = [] + + # read everything we need into memory + for line in sys.stdin.readlines(): + fields = line.split(";") + if len(fields) > 5: + # http://www.unicode.org/reports/tr44/tr44-14.html#UnicodeData.txt + general_category = fields[2] + decomposition = fields[5] + decomposition = re.sub(decomposition_type_pattern, ' ', decomposition) + id = int(fields[0], 16) + combining_ids = [int(s, 16) for s in decomposition.split(" ") if s != ""] + codepoint = Codepoint(id, general_category, combining_ids) + table[id] = codepoint + all.append(codepoint) + + # walk through all the codepoints looking for interesting mappings + for codepoint in all: + if codepoint.general_category.startswith('L') and \ + len(codepoint.combining_ids) > 1: + if is_letter_with_marks(codepoint, table): + print_record(codepoint.id, + chr(get_plain_letter(codepoint, table).id)) + elif expand_ligatures and is_ligature(codepoint, table): + print_record(codepoint.id, + "".join(unichr(combining_codepoint.id) + for combining_codepoint \ + in get_plain_letters(codepoint, table))) + + # some special cases + print_record(0x00d8, "O") # LATIN CAPITAL LETTER O WITH STROKE + print_record(0x00f8, "o") # LATIN SMALL LETTER O WITH STROKE + print_record(0x0110, "D") # LATIN CAPITAL LETTER D WITH STROKE + print_record(0x0111, "d") # LATIN SMALL LETTER D WITH STROKE + print_record(0x0131, "i") # LATIN SMALL LETTER DOTLESS I + print_record(0x0126, "H") # LATIN CAPITAL LETTER H WITH STROKE + print_record(0x0127, "h") # LATIN SMALL LETTER H WITH STROKE + print_record(0x0141, "L") # LATIN CAPITAL LETTER L WITH STROKE + print_record(0x0142, "l") # LATIN SMALL LETTER L WITH STROKE + print_record(0x0149, "'n") # LATIN SMALL LETTER N PRECEDED BY APOSTROPHE + print_record(0x0166, "T") # LATIN CAPITAL LETTER T WITH STROKE + print_record(0x0167, "t") # LATIN SMALL LETTER t WITH STROKE + print_record(0x0401, u"\u0415") # CYRILLIC CAPITAL LETTER IO + print_record(0x0451, u"\u0435") # CYRILLIC SMALL LETTER IO + if expand_ligatures: + print_record(0x00c6, "AE") # LATIN CAPITAL LETTER AE + print_record(0x00df, "ss") # LATIN SMALL LETTER SHARP S + print_record(0x00e6, "ae") # LATIN SMALL LETTER AE + print_record(0x0152, "OE") # LATIN CAPITAL LIGATURE OE + print_record(0x0153, "oe") # LATIN SMALL LIGATURE OE + +if __name__ == "__main__": + main(len(sys.argv) == 2 and sys.argv[1] == "--expand-ligatures") |