diac_utils.py

from typing import List

import torch as T
import numpy as np

from pyarabic.araby import (
    tokenize,
    strip_tashkeel,
    strip_tatweel,
    DIACRITICS
)

SEPARATE_DIACRITICS = {
    "FATHA": 1,
    "KASRA": 2,
    "DAMMA": 3,
    "SUKUN": 4
}

HARAKAT_MAP = [
    #^ (haraka, tanween, shadda)
    (0,0,0), #< No diacs on char
    (1,0,0),
    (1,1,0), #< Tanween on 2nd slot
    (2,0,0),
    (2,1,0),
    (3,0,0),
    (3,1,0),
    (4,0,0),
    (0,0,1), #< shadda on 3rd slot
    (1,0,1),
    (1,1,1),
    (2,0,1),
    (2,1,1),
    (3,0,1),
    (3,1,1),
    (0,0,0), #< Padding == -1 (also for spaces)
]

SPECIAL_TOKENS = ['<pad>', '<unk>', '<num>', '<punc>']
LETTER_LIST = SPECIAL_TOKENS + list("ءآأؤإئابةتثجحخدذرزسشصضطظعغفقكلمنهوىي")
CLASSES_LIST = [' ', 'َ', 'ً', 'ُ', 'ٌ', 'ِ', 'ٍ', 'ْ', 'ّ', 'َّ', 'ًّ', 'ُّ', 'ٌّ', 'ِّ', 'ٍّ']
DIACRITICS_SHORT = [' ', 'َ', 'ً', 'ِ', 'ٍ', 'ُ', 'ٌ', 'ْ', 'ّ']
NUMBERS = list("0123456789")
DELIMITERS = ["،","؛",",",";","«","»","{","}","(",")","[","]",".","*","-",":","?","!","؟"]

UNKNOWN_DIACRITICS = list(set(DIACRITICS).difference(set(DIACRITICS_SHORT)))

def shakkel_char(diac: int, tanween: bool, shadda: bool) -> str:
    returned_text = ""
    if shadda and diac != SEPARATE_DIACRITICS["SUKUN"]:
        returned_text += "\u0651"

    if diac == SEPARATE_DIACRITICS["FATHA"]:
        returned_text += "\u064E" if not tanween else "\u064B"
    elif diac == SEPARATE_DIACRITICS["KASRA"]:
        returned_text += "\u0650" if not tanween else "\u064D"
    elif diac == SEPARATE_DIACRITICS["DAMMA"]:
        returned_text += "\u064F" if not tanween else "\u064C"
    elif diac == SEPARATE_DIACRITICS["SUKUN"]:
        returned_text += "\u0652"

    return returned_text

def diac_ids_of_line(line: str):
    words = tokenize(line)
    diacs = []
    for word in words:
        word_chars = split_word_on_characters_with_diacritics(word)
        cx, cy, cy_3head = create_label_for_word(word_chars)
        diacs.extend(cy)
        diacs.append(-1)
    return np.array(diacs[:-1])

def strip_unknown_tashkeel(word: str):
    #! FIXME! warnings.warn("Stripping unknown tashkeel is disabled.")
    return word
    return ''.join(c for c in word if c not in UNKNOWN_DIACRITICS)

def split_word_on_characters_with_diacritics(word: str):
    '''
    TODO! Make faster without deque and looping
    Returns: List[List[char: "letter or diacritic"]]
    '''
    chars_w_diac = []
    i_start = 0
    for i_c, c in enumerate(word):
        #! FIXME! DIACRITICS_SHORT is missing a lot of less common diacritics ...
        #! which are then treated as letters during splitting.
        # if c not in DIACRITICS:
        if c not in DIACRITICS_SHORT:
            sub = list(word[i_start:i_c])
            chars_w_diac.append(sub)
            i_start = i_c
    sub = list(word[i_start:])
    if sub:
        chars_w_diac.append(sub)
    if not chars_w_diac[0]:
        chars_w_diac = chars_w_diac[1:]
    return chars_w_diac


def char_type(char: str):
    if char in LETTER_LIST:
        return LETTER_LIST.index(char)
    elif char in NUMBERS:
        return LETTER_LIST.index('<num>')
    elif char in DELIMITERS:
        return LETTER_LIST.index('<punc>')
    else:
        return LETTER_LIST.index('<unk>')

def create_labels(char_w_diac: str):
    remap_dict = {0: 0, 1: 1, 3: 2, 5: 3, 7: 4}
    char_w_diac = [char_w_diac[0]] + list(set(char_w_diac[1:]))
    if len(char_w_diac) > 3:
        char_w_diac = char_w_diac[:2] if DIACRITICS_SHORT[8] not in char_w_diac else char_w_diac[:3]

    char_idx = None
    diacritic_index = None
    head_3 = None

    char_idx = char_type(char_w_diac[0])
    diacs = set(char_w_diac[1:])
    diac_h3 = [0, 0, 0]
    for diac in diacs:
        if diac in DIACRITICS_SHORT:
            diac_idx = DIACRITICS_SHORT.index(diac)
            if diac_idx in [2, 4, 6]: #< Tanween
                diac_h3[0] = remap_dict[diac_idx - 1]
                diac_h3[1] = 1
            elif diac_idx == 8: #< shadda
                diac_h3[2] = 1
            else: #< Haraka or sukoon
                diac_h3[0] = remap_dict[diac_idx]
    assert not (diac_h3[0] == 4 and (diac_h3[1] or diac_h3[2]))
    diacritic_index = HARAKAT_MAP.index(tuple(diac_h3))
    return char_idx, diacritic_index, diac_h3
    if len(char_w_diac) == 1:
        return char_idx, 0, [remap_dict[0], 0, 0]
    elif len(char_w_diac) == 2:  # If shadda OR diac
        diacritic_index = DIACRITICS_SHORT.index(char_w_diac[1])
        if diacritic_index in [2, 4, 6]:  # list of tanween
            head_3 = [remap_dict[diacritic_index - 1], 1, 0]
        elif diacritic_index == 8:
            head_3 = [0, 0, 1]
        else:
            head_3 = [remap_dict[diacritic_index], 0, 0]
    elif len(char_w_diac) == 3:  # If shadda AND diac
        if DIACRITICS_SHORT[8] == char_w_diac[1]:
            diacritic_index = DIACRITICS_SHORT.index(char_w_diac[2])
        else:
            diacritic_index = DIACRITICS_SHORT.index(char_w_diac[1])

        if diacritic_index in [2, 4, 6]:  # list of tanween
            head_3 = [remap_dict[diacritic_index - 1], 1, 1]
        else:
            head_3 = [remap_dict[diacritic_index], 0, 1]
        diacritic_index = diacritic_index+8

    return char_idx, diacritic_index, head_3

def create_label_for_word(split_word: List[List[str]]):
    word_char_indices = []
    word_diac_indices = []
    word_diac_indices_h3 = []
    for char_w_diac in split_word:
        char_idx, diac_idx, diac_h3 = create_labels(char_w_diac)
        if char_idx == None:
            print(split_word)
            raise ValueError(char_idx)
        word_char_indices.append(char_idx)
        word_diac_indices.append(diac_idx)
        word_diac_indices_h3.append(diac_h3)
    return word_char_indices, word_diac_indices, word_diac_indices_h3


def flat_2_3head(output: T.Tensor):
    '''
    output: [b tw tc]
    '''
    haraka, tanween, shadda = [], [], []

    # 0, 1,  2, 3,  4, 5,  6, 7, 8,  9,     10,  11,   12,  13,   14
    # 0, F, FF, K, KK, D, DD, S, Sh, ShF, ShFF, ShK, ShKK, ShD, ShDD

    b, ts, tw = output.shape

    for b_idx in range(b):
        h_s, t_s, s_s = [], [], []
        for w_idx in range(ts):
            h_w, t_w, s_w = [], [], []
            for c_idx in range(tw):
                c = HARAKAT_MAP[int(output[b_idx, w_idx, c_idx])]
                h_w  += [c[0]]
                t_w += [c[1]]
                s_w  += [c[2]]
            h_s += [h_w]
            t_s += [t_w]
            s_s += [s_w]

        haraka  += [h_s]
        tanween += [t_s]
        shadda  += [s_s]


    return haraka, tanween, shadda

def flat2_3head(diac_idx):
    '''
    diac_idx: [tw]
    '''
    haraka, tanween, shadda = [], [], []
    # 0, 1,  2, 3,  4, 5,  6, 7, 8,  9,     10,  11,   12,  13,   14
    # 0, F, FF, K, KK, D, DD, S, Sh, ShF, ShFF, ShK, ShKK, ShD, ShDD

    for diac in diac_idx:
        c_out = HARAKAT_MAP[diac]
        haraka += [c_out[0]]
        tanween += [c_out[1]]
        shadda += [c_out[2]]

    return np.array(haraka), np.array(tanween), np.array(shadda)