# -*- coding: utf-8 -*-
# Copyright 2018 by Christopher C. Little.
# This file is part of Abydos.
#
# Abydos is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Abydos is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Abydos. If not, see <http://www.gnu.org/licenses/>.
"""abydos.phonetic._eudex.
The phonetic._eudex module implements the Eudex phonetic hash.
"""
from __future__ import unicode_literals
from six.moves import range
__all__ = ['eudex']
[docs]def eudex(word, max_length=8):
"""Return the eudex phonetic hash of a word.
This implementation of eudex phonetic hashing is based on the specification
(not the reference implementation) at :cite:`Ticki:2016`.
Further details can be found at :cite:`Ticki:2016b`.
:param str word: the word to transform
:param int max_length: the length in bits of the code returned (default 8)
:returns: the eudex hash
:rtype: int
>>> eudex('Colin')
432345564238053650
>>> eudex('Christopher')
433648490138894409
>>> eudex('Niall')
648518346341351840
>>> eudex('Smith')
720575940412906756
>>> eudex('Schmidt')
720589151732307997
"""
_trailing_phones = {
'a': 0, # a
'b': 0b01001000, # b
'c': 0b00001100, # c
'd': 0b00011000, # d
'e': 0, # e
'f': 0b01000100, # f
'g': 0b00001000, # g
'h': 0b00000100, # h
'i': 1, # i
'j': 0b00000101, # j
'k': 0b00001001, # k
'l': 0b10100000, # l
'm': 0b00000010, # m
'n': 0b00010010, # n
'o': 0, # o
'p': 0b01001001, # p
'q': 0b10101000, # q
'r': 0b10100001, # r
's': 0b00010100, # s
't': 0b00011101, # t
'u': 1, # u
'v': 0b01000101, # v
'w': 0b00000000, # w
'x': 0b10000100, # x
'y': 1, # y
'z': 0b10010100, # z
'ß': 0b00010101, # ß
'à': 0, # à
'á': 0, # á
'â': 0, # â
'ã': 0, # ã
'ä': 0, # ä[æ]
'å': 1, # å[oː]
'æ': 0, # æ[æ]
'ç': 0b10010101, # ç[t͡ʃ]
'è': 1, # è
'é': 1, # é
'ê': 1, # ê
'ë': 1, # ë
'ì': 1, # ì
'í': 1, # í
'î': 1, # î
'ï': 1, # ï
'ð': 0b00010101, # ð[ð̠](represented as a non-plosive T)
'ñ': 0b00010111, # ñ[nj](represented as a combination of n and j)
'ò': 0, # ò
'ó': 0, # ó
'ô': 0, # ô
'õ': 0, # õ
'ö': 1, # ö[ø]
'÷': 0b11111111, # ÷
'ø': 1, # ø[ø]
'ù': 1, # ù
'ú': 1, # ú
'û': 1, # û
'ü': 1, # ü
'ý': 1, # ý
'þ': 0b00010101, # þ[ð̠](represented as a non-plosive T)
'ÿ': 1, # ÿ
}
_initial_phones = {
'a': 0b10000100, # a*
'b': 0b00100100, # b
'c': 0b00000110, # c
'd': 0b00001100, # d
'e': 0b11011000, # e*
'f': 0b00100010, # f
'g': 0b00000100, # g
'h': 0b00000010, # h
'i': 0b11111000, # i*
'j': 0b00000011, # j
'k': 0b00000101, # k
'l': 0b01010000, # l
'm': 0b00000001, # m
'n': 0b00001001, # n
'o': 0b10010100, # o*
'p': 0b00100101, # p
'q': 0b01010100, # q
'r': 0b01010001, # r
's': 0b00001010, # s
't': 0b00001110, # t
'u': 0b11100000, # u*
'v': 0b00100011, # v
'w': 0b00000000, # w
'x': 0b01000010, # x
'y': 0b11100100, # y*
'z': 0b01001010, # z
'ß': 0b00001011, # ß
'à': 0b10000101, # à
'á': 0b10000101, # á
'â': 0b10000000, # â
'ã': 0b10000110, # ã
'ä': 0b10100110, # ä [æ]
'å': 0b11000010, # å [oː]
'æ': 0b10100111, # æ [æ]
'ç': 0b01010100, # ç [t͡ʃ]
'è': 0b11011001, # è
'é': 0b11011001, # é
'ê': 0b11011001, # ê
'ë': 0b11000110, # ë [ə] or [œ]
'ì': 0b11111001, # ì
'í': 0b11111001, # í
'î': 0b11111001, # î
'ï': 0b11111001, # ï
'ð': 0b00001011, # ð [ð̠] (represented as a non-plosive T)
'ñ': 0b00001011, # ñ [nj] (represented as a combination of n and j)
'ò': 0b10010101, # ò
'ó': 0b10010101, # ó
'ô': 0b10010101, # ô
'õ': 0b10010101, # õ
'ö': 0b11011100, # ö [œ] or [ø]
'÷': 0b11111111, # ÷
'ø': 0b11011101, # ø [œ] or [ø]
'ù': 0b11100001, # ù
'ú': 0b11100001, # ú
'û': 0b11100001, # û
'ü': 0b11100101, # ü
'ý': 0b11100101, # ý
'þ': 0b00001011, # þ [ð̠] (represented as a non-plosive T)
'ÿ': 0b11100101, # ÿ
}
# Lowercase input & filter unknown characters
word = ''.join(char for char in word.lower() if char in _initial_phones)
if not word:
word = '÷'
# Perform initial eudex coding of each character
values = [_initial_phones[word[0]]]
values += [_trailing_phones[char] for char in word[1:]]
# Right-shift by one to determine if second instance should be skipped
shifted_values = [_ >> 1 for _ in values]
condensed_values = [values[0]]
for n in range(1, len(shifted_values)):
if shifted_values[n] != shifted_values[n - 1]:
condensed_values.append(values[n])
# Add padding after first character & trim beyond max_length
values = (
[condensed_values[0]]
+ [0] * max(0, max_length - len(condensed_values))
+ condensed_values[1:max_length]
)
# Combine individual character values into eudex hash
hash_value = 0
for val in values:
hash_value = (hash_value << 8) | val
return hash_value
if __name__ == '__main__':
import doctest
doctest.testmod()