abydos.phonetic._alpha_sis

Complexity

Total Complexity

15

Size/Duplication

Total Lines	283
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

1 Method

Rating	Name	Duplication	Size	Complexity
F	AlphaSIS.encode()	0	88	14

# -*- coding: utf-8 -*-

# Copyright 2014-2018 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._alpha_sis.

IBM's Alpha Search Inquiry System coding
"""

from __future__ import (
    absolute_import,
    division,
    print_function,
    unicode_literals,
)

from unicodedata import normalize as unicode_normalize

from six import text_type
from six.moves import range

from ._phonetic import _Phonetic

__all__ = ['AlphaSIS', 'alpha_sis']


class AlphaSIS(_Phonetic):
    """Alpha-SIS.

    The Alpha Search Inquiry System code is defined in :cite:`IBM:1973`.
    This implementation is based on the description in :cite:`Moore:1977`.
    """

    _alpha_sis_initials = {
        'GF': '08',
        'GM': '03',
        'GN': '02',
        'KN': '02',
        'PF': '08',
        'PN': '02',
        'PS': '00',
        'WR': '04',
        'A': '1',
        'E': '1',
        'H': '2',
        'I': '1',
        'J': '3',
        'O': '1',
        'U': '1',
        'W': '4',
        'Y': '5',
    }
    _alpha_sis_initials_order = (
        'GF',
        'GM',
        'GN',
        'KN',
        'PF',
        'PN',
        'PS',
        'WR',
        'A',
        'E',
        'H',
        'I',
        'J',
        'O',
        'U',
        'W',
        'Y',
    )
    _alpha_sis_basic = {
        'SCH': '6',
        'CZ': ('70', '6', '0'),
        'CH': ('6', '70', '0'),
        'CK': ('7', '6'),
        'DS': ('0', '10'),
        'DZ': ('0', '10'),
        'TS': ('0', '10'),
        'TZ': ('0', '10'),
        'CI': '0',
        'CY': '0',
        'CE': '0',
        'SH': '6',
        'DG': '7',
        'PH': '8',
        'C': ('7', '6'),
        'K': ('7', '6'),
        'Z': '0',
        'S': '0',
        'D': '1',
        'T': '1',
        'N': '2',
        'M': '3',
        'R': '4',
        'L': '5',
        'J': '6',
        'G': '7',
        'Q': '7',
        'X': '7',
        'F': '8',
        'V': '8',
        'B': '9',
        'P': '9',
    }
    _alpha_sis_basic_order = (
        'SCH',
        'CZ',
        'CH',
        'CK',
        'DS',
        'DZ',
        'TS',
        'TZ',
        'CI',
        'CY',
        'CE',
        'SH',
        'DG',
        'PH',
        'C',
        'K',
        'Z',
        'S',
        'D',
        'T',
        'N',
        'M',
        'R',
        'L',
        'J',
        'C',
        'G',
        'K',
        'Q',
        'X',
        'F',
        'V',
        'B',
        'P',
    )

    def encode(self, word, max_length=14):
        """Return the IBM Alpha Search Inquiry System code for a word.

        A collection is necessary as the return type since there can be
        multiple values for a single word. But the collection must be ordered
        since the first value is the primary coding.

        Parameters
        ----------
        word : str
            The word to transform
        max_length : int
            The length of the code returned (defaults to 14)

        Returns
        -------
        tuple
            The Alpha-SIS value

        Examples
        --------
        >>> pe = AlphaSIS()
        >>> pe.encode('Christopher')
        ('06401840000000', '07040184000000', '04018400000000')
        >>> pe.encode('Niall')
        ('02500000000000',)
        >>> pe.encode('Smith')
        ('03100000000000',)
        >>> pe.encode('Schmidt')
        ('06310000000000',)

        """
        alpha = ['']
        pos = 0
        word = unicode_normalize('NFKD', text_type(word.upper()))
        word = word.replace('ß', 'SS')
        word = ''.join(c for c in word if c in self._uc_set)

        # Clamp max_length to [4, 64]
        if max_length != -1:
            max_length = min(max(4, max_length), 64)
        else:
            max_length = 64

        # Do special processing for initial substrings
        for k in self._alpha_sis_initials_order:
            if word.startswith(k):
                alpha[0] += self._alpha_sis_initials[k]
                pos += len(k)
                break

        # Add a '0' if alpha is still empty
        if not alpha[0]:
            alpha[0] += '0'

        # Whether or not any special initial codes were encoded, iterate
        # through the length of the word in the main encoding loop
        while pos < len(word):
            orig_pos = pos
            for k in self._alpha_sis_basic_order:
                if word[pos:].startswith(k):
                    if isinstance(self._alpha_sis_basic[k], tuple):
                        newalpha = []
                        for i in range(len(self._alpha_sis_basic[k])):
                            newalpha += [
                                _ + self._alpha_sis_basic[k][i] for _ in alpha
                            ]
                        alpha = newalpha
                    else:
                        alpha = [_ + self._alpha_sis_basic[k] for _ in alpha]
                    pos += len(k)
                    break
            if pos == orig_pos:
                alpha = [_ + '_' for _ in alpha]
                pos += 1

        # Trim doublets and placeholders
        for i in range(len(alpha)):
            pos = 1
            while pos < len(alpha[i]):
                if alpha[i][pos] == alpha[i][pos - 1]:
                    alpha[i] = alpha[i][:pos] + alpha[i][pos + 1 :]
                pos += 1
        alpha = (_.replace('_', '') for _ in alpha)

The variable _ does not seem to be defined.

        # Trim codes and return tuple
        alpha = ((_ + ('0' * max_length))[:max_length] for _ in alpha)
        return tuple(alpha)


def alpha_sis(word, max_length=14):
    """Return the IBM Alpha Search Inquiry System code for a word.

    This is a wrapper for :py:meth:`AlphaSIS.encode`.

    Parameters
    ----------
    word : str
        The word to transform
    max_length : int
        The length of the code returned (defaults to 14)

    Returns
    -------
    tuple
        The Alpha-SIS value

    Examples
    --------
    >>> alpha_sis('Christopher')
    ('06401840000000', '07040184000000', '04018400000000')
    >>> alpha_sis('Niall')
    ('02500000000000',)
    >>> alpha_sis('Smith')
    ('03100000000000',)
    >>> alpha_sis('Schmidt')
    ('06310000000000',)

    """
    return AlphaSIS().encode(word, max_length)


if __name__ == '__main__':
    import doctest

    doctest.testmod()