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Add Python script for buiding unaccent.rules from Unicode data. Don't backpatch because unaccent changes may require tsvector/index rebuild. Thomas Munro <thomas.munro@enterprisedb.com>pull/7/head
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#!/usr/bin/python |
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# |
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# This script builds unaccent.rules on standard output when given the |
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# contents of UnicodeData.txt[1] on standard input. Optionally includes |
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# ligature expansion, if --expand-ligatures is given on the command line. |
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# |
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# The approach is to use the Unicode decomposition data to identify |
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# precomposed codepoints that are equivalent to a ligature of several |
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# letters, or a base letter with any number of diacritical marks. |
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# There is also a small set of special cases for codepoints that we |
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# traditionally support even though Unicode doesn't consider them to |
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# be ligatures or letters with marks. |
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# |
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# [1] http://unicode.org/Public/7.0.0/ucd/UnicodeData.txt |
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|
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import re |
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import sys |
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|
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def print_record(codepoint, letter): |
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print (unichr(codepoint) + "\t" + letter).encode("UTF-8") |
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|
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class Codepoint: |
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def __init__(self, id, general_category, combining_ids): |
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self.id = id |
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self.general_category = general_category |
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self.combining_ids = combining_ids |
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|
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def is_plain_letter(codepoint): |
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"""Return true if codepoint represents a plain ASCII letter.""" |
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return (codepoint.id >= ord('a') and codepoint.id <= ord('z')) or \ |
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(codepoint.id >= ord('A') and codepoint.id <= ord('Z')) |
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|
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def is_mark(codepoint): |
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"""Returns true for diacritical marks (combining codepoints).""" |
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return codepoint.general_category in ("Mn", "Me", "Mc") |
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|
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def is_letter_with_marks(codepoint, table): |
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"""Returns true for plain letters combined with one or more marks.""" |
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# See http://www.unicode.org/reports/tr44/tr44-14.html#General_Category_Values |
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return len(codepoint.combining_ids) > 1 and \ |
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is_plain_letter(table[codepoint.combining_ids[0]]) and \ |
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all(is_mark(table[i]) for i in codepoint.combining_ids[1:]) |
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|
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def is_letter(codepoint, table): |
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"""Return true for letter with or without diacritical marks.""" |
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return is_plain_letter(codepoint) or is_letter_with_marks(codepoint, table) |
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|
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def get_plain_letter(codepoint, table): |
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"""Return the base codepoint without marks.""" |
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if is_letter_with_marks(codepoint, table): |
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return table[codepoint.combining_ids[0]] |
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elif is_plain_letter(codepoint): |
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return codepoint |
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else: |
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raise "mu" |
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def is_ligature(codepoint, table): |
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"""Return true for letters combined with letters.""" |
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return all(is_letter(table[i], table) for i in codepoint.combining_ids) |
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|
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def get_plain_letters(codepoint, table): |
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"""Return a list of plain letters from a ligature.""" |
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assert(is_ligature(codepoint, table)) |
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return [get_plain_letter(table[id], table) for id in codepoint.combining_ids] |
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def main(expand_ligatures): |
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# http://www.unicode.org/reports/tr44/tr44-14.html#Character_Decomposition_Mappings |
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decomposition_type_pattern = re.compile(" *<[^>]*> *") |
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table = {} |
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all = [] |
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|
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# read everything we need into memory |
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for line in sys.stdin.readlines(): |
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fields = line.split(";") |
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if len(fields) > 5: |
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# http://www.unicode.org/reports/tr44/tr44-14.html#UnicodeData.txt |
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general_category = fields[2] |
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decomposition = fields[5] |
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decomposition = re.sub(decomposition_type_pattern, ' ', decomposition) |
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id = int(fields[0], 16) |
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combining_ids = [int(s, 16) for s in decomposition.split(" ") if s != ""] |
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codepoint = Codepoint(id, general_category, combining_ids) |
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table[id] = codepoint |
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all.append(codepoint) |
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|
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# walk through all the codepoints looking for interesting mappings |
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for codepoint in all: |
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if codepoint.general_category.startswith('L') and \ |
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len(codepoint.combining_ids) > 1: |
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if is_letter_with_marks(codepoint, table): |
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print_record(codepoint.id, |
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chr(get_plain_letter(codepoint, table).id)) |
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elif expand_ligatures and is_ligature(codepoint, table): |
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print_record(codepoint.id, |
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"".join(unichr(combining_codepoint.id) |
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for combining_codepoint \ |
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in get_plain_letters(codepoint, table))) |
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|
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# some special cases |
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print_record(0x00d8, "O") # LATIN CAPITAL LETTER O WITH STROKE |
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print_record(0x00f8, "o") # LATIN SMALL LETTER O WITH STROKE |
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print_record(0x0110, "D") # LATIN CAPITAL LETTER D WITH STROKE |
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print_record(0x0111, "d") # LATIN SMALL LETTER D WITH STROKE |
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print_record(0x0131, "i") # LATIN SMALL LETTER DOTLESS I |
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print_record(0x0126, "H") # LATIN CAPITAL LETTER H WITH STROKE |
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print_record(0x0127, "h") # LATIN SMALL LETTER H WITH STROKE |
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print_record(0x0141, "L") # LATIN CAPITAL LETTER L WITH STROKE |
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print_record(0x0142, "l") # LATIN SMALL LETTER L WITH STROKE |
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print_record(0x0149, "'n") # LATIN SMALL LETTER N PRECEDED BY APOSTROPHE |
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print_record(0x0166, "T") # LATIN CAPITAL LETTER T WITH STROKE |
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print_record(0x0167, "t") # LATIN SMALL LETTER t WITH STROKE |
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print_record(0x0401, u"\u0415") # CYRILLIC CAPITAL LETTER IO |
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print_record(0x0451, u"\u0435") # CYRILLIC SMALL LETTER IO |
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if expand_ligatures: |
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print_record(0x00c6, "AE") # LATIN CAPITAL LETTER AE |
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print_record(0x00df, "ss") # LATIN SMALL LETTER SHARP S |
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print_record(0x00e6, "ae") # LATIN SMALL LETTER AE |
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print_record(0x0152, "OE") # LATIN CAPITAL LIGATURE OE |
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print_record(0x0153, "oe") # LATIN SMALL LIGATURE OE |
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if __name__ == "__main__": |
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main(len(sys.argv) == 2 and sys.argv[1] == "--expand-ligatures") |
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