mirror of https://github.com/explosion/spaCy.git
261 lines
11 KiB
Cython
261 lines
11 KiB
Cython
# cython: embedsignature=True
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from __future__ import unicode_literals
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from os import path
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import re
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from cython.operator cimport dereference as deref
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from cython.operator cimport preincrement as preinc
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from cymem.cymem cimport Pool
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from preshed.maps cimport PreshMap
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from .structs cimport UniStr
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from .strings cimport slice_unicode
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from .morphology cimport set_morph_from_dict
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from . import util
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from .util import read_lang_data
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from .tokens import Tokens
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cdef class Tokenizer:
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def __init__(self, Vocab vocab, rules, prefix_re, suffix_re, infix_re,
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pos_tags, tag_names):
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self.mem = Pool()
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self._cache = PreshMap()
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self._specials = PreshMap()
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self._prefix_re = prefix_re
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self._suffix_re = suffix_re
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self._infix_re = infix_re
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self.vocab = vocab
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self._load_special_tokenization(rules, pos_tags, tag_names)
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cpdef Tokens tokens_from_list(self, list strings):
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cdef int length = sum([len(s) for s in strings])
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cdef Tokens tokens = Tokens(self.vocab, length)
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if length == 0:
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return tokens
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cdef UniStr string_struct
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cdef unicode py_string
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cdef int idx = 0
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for i, py_string in enumerate(strings):
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slice_unicode(&string_struct, py_string, 0, len(py_string))
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tokens.push_back(idx, <const LexemeC*>self.vocab.get(tokens.mem, &string_struct))
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idx += len(py_string) + 1
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return tokens
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def __call__(self, unicode string):
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"""Tokenize a string.
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The tokenization rules are defined in three places:
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* The data/<lang>/tokenization table, which handles special cases like contractions;
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* The data/<lang>/prefix file, used to build a regex to split off prefixes;
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* The data/<lang>/suffix file, used to build a regex to split off suffixes.
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The string is first split on whitespace. To tokenize a whitespace-delimited
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chunk, we first try to look it up in the special-cases. If it's not found,
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we split off a prefix, and then try again. If it's still not found, we
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split off a suffix, and repeat.
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Args:
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string (unicode): The string to be tokenized.
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Returns:
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tokens (Tokens): A Tokens object, giving access to a sequence of LexemeCs.
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"""
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cdef int length = len(string)
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cdef Tokens tokens = Tokens(self.vocab, length)
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if length == 0:
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return tokens
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cdef int i = 0
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cdef int start = 0
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cdef bint cache_hit
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cdef Py_UNICODE* chars = string
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cdef bint in_ws = Py_UNICODE_ISSPACE(chars[0])
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cdef UniStr span
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for i in range(1, length):
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if Py_UNICODE_ISSPACE(chars[i]) != in_ws:
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if start < i:
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slice_unicode(&span, chars, start, i)
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cache_hit = self._try_cache(start, span.key, tokens)
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if not cache_hit:
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self._tokenize(tokens, &span, start, i)
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in_ws = not in_ws
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start = i
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if chars[i] == ' ':
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start += 1
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i += 1
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if start < i:
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slice_unicode(&span, chars, start, i)
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cache_hit = self._try_cache(start, span.key, tokens)
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if not cache_hit:
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self._tokenize(tokens, &span, start, i)
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return tokens
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cdef int _try_cache(self, int idx, hash_t key, Tokens tokens) except -1:
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#cached = <Cached*>self._specials.get(key)
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cached = <_Cached*>self._cache.get(key)
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if cached == NULL:
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return False
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cdef int i
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if cached.is_lex:
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for i in range(cached.length):
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idx = tokens.push_back(idx, cached.data.lexemes[i])
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else:
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for i in range(cached.length):
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idx = tokens.push_back(idx, &cached.data.tokens[i])
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return True
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cdef int _tokenize(self, Tokens tokens, UniStr* span, int start, int end) except -1:
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cdef vector[LexemeC*] prefixes
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cdef vector[LexemeC*] suffixes
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cdef hash_t orig_key
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cdef int orig_size
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orig_key = span.key
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orig_size = tokens.length
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self._split_affixes(span, &prefixes, &suffixes)
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self._attach_tokens(tokens, start, span, &prefixes, &suffixes)
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self._save_cached(&tokens.data[orig_size], orig_key, tokens.length - orig_size)
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cdef UniStr* _split_affixes(self, UniStr* string, vector[const LexemeC*] *prefixes,
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vector[const LexemeC*] *suffixes) except NULL:
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cdef size_t i
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cdef UniStr prefix
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cdef UniStr suffix
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cdef UniStr minus_pre
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cdef UniStr minus_suf
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cdef size_t last_size = 0
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while string.n != 0 and string.n != last_size:
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last_size = string.n
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pre_len = self._find_prefix(string.chars, string.n)
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if pre_len != 0:
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slice_unicode(&prefix, string.chars, 0, pre_len)
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slice_unicode(&minus_pre, string.chars, pre_len, string.n)
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# Check whether we've hit a special-case
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if minus_pre.n >= 1 and self._specials.get(minus_pre.key) != NULL:
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string[0] = minus_pre
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prefixes.push_back(self.vocab.get(self.vocab.mem, &prefix))
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break
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suf_len = self._find_suffix(string.chars, string.n)
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if suf_len != 0:
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slice_unicode(&suffix, string.chars, string.n - suf_len, string.n)
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slice_unicode(&minus_suf, string.chars, 0, string.n - suf_len)
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# Check whether we've hit a special-case
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if minus_suf.n >= 1 and self._specials.get(minus_suf.key) != NULL:
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string[0] = minus_suf
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suffixes.push_back(self.vocab.get(self.vocab.mem, &suffix))
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break
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if pre_len and suf_len and (pre_len + suf_len) <= string.n:
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slice_unicode(string, string.chars, pre_len, string.n - suf_len)
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prefixes.push_back(self.vocab.get(self.vocab.mem, &prefix))
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suffixes.push_back(self.vocab.get(self.vocab.mem, &suffix))
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elif pre_len:
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string[0] = minus_pre
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prefixes.push_back(self.vocab.get(self.vocab.mem, &prefix))
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elif suf_len:
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string[0] = minus_suf
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suffixes.push_back(self.vocab.get(self.vocab.mem, &suffix))
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if self._specials.get(string.key):
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break
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return string
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cdef int _attach_tokens(self, Tokens tokens, int idx, UniStr* string,
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vector[const LexemeC*] *prefixes,
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vector[const LexemeC*] *suffixes) except -1:
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cdef bint cache_hit
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cdef int split
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cdef const LexemeC* const* lexemes
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cdef LexemeC* lexeme
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cdef UniStr span
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cdef int i
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if prefixes.size():
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for i in range(prefixes.size()):
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idx = tokens.push_back(idx, prefixes[0][i])
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if string.n != 0:
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cache_hit = self._try_cache(idx, string.key, tokens)
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if cache_hit:
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idx = tokens.data[tokens.length - 1].idx + 1
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else:
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split = self._find_infix(string.chars, string.n)
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if split == 0 or split == -1:
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idx = tokens.push_back(idx, self.vocab.get(tokens.mem, string))
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else:
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slice_unicode(&span, string.chars, 0, split)
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idx = tokens.push_back(idx, self.vocab.get(tokens.mem, &span))
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slice_unicode(&span, string.chars, split, split+1)
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idx = tokens.push_back(idx, self.vocab.get(tokens.mem, &span))
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slice_unicode(&span, string.chars, split + 1, string.n)
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idx = tokens.push_back(idx, self.vocab.get(tokens.mem, &span))
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cdef vector[const LexemeC*].reverse_iterator it = suffixes.rbegin()
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while it != suffixes.rend():
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idx = tokens.push_back(idx, deref(it))
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preinc(it)
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cdef int _save_cached(self, const TokenC* tokens, hash_t key, int n) except -1:
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cdef int i
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for i in range(n):
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if tokens[i].lex.id == 1:
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return 0
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cached = <_Cached*>self.mem.alloc(1, sizeof(_Cached))
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cached.length = n
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cached.is_lex = True
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lexemes = <const LexemeC**>self.mem.alloc(n, sizeof(LexemeC**))
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for i in range(n):
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lexemes[i] = tokens[i].lex
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cached.data.lexemes = <const LexemeC* const*>lexemes
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self._cache.set(key, cached)
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cdef int _find_infix(self, Py_UNICODE* chars, size_t length) except -1:
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cdef unicode string = chars[:length]
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match = self._infix_re.search(string)
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return match.start() if match is not None else 0
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cdef int _find_prefix(self, Py_UNICODE* chars, size_t length) except -1:
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cdef unicode string = chars[:length]
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match = self._prefix_re.search(string)
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return (match.end() - match.start()) if match is not None else 0
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cdef int _find_suffix(self, Py_UNICODE* chars, size_t length) except -1:
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cdef unicode string = chars[:length]
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match = self._suffix_re.search(string)
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return (match.end() - match.start()) if match is not None else 0
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def _load_special_tokenization(self, object rules, object tag_map, object tag_names):
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'''Add a special-case tokenization rule.
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'''
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cdef int i
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cdef unicode chunk
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cdef list substrings
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cdef unicode form
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cdef unicode lemma
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cdef dict props
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cdef LexemeC** lexemes
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cdef hash_t hashed
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cdef UniStr string
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for chunk, substrings in sorted(rules.items()):
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tokens = <TokenC*>self.mem.alloc(len(substrings) + 1, sizeof(TokenC))
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for i, props in enumerate(substrings):
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form = props['F']
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lemma = props.get("L", None)
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slice_unicode(&string, form, 0, len(form))
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tokens[i].lex = <LexemeC*>self.vocab.get(self.vocab.mem, &string)
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if lemma:
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tokens[i].lemma = self.vocab.strings[lemma]
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if 'pos' in props:
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# TODO: Clean up this mess...
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tokens[i].tag = tag_names.index(props['pos'])
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tokens[i].pos = tag_map[props['pos']][0]
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# These are defaults, which can be over-ridden by the
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# token-specific props.
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set_morph_from_dict(&tokens[i].morph, tag_map[props['pos']][1])
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set_morph_from_dict(&tokens[i].morph, props)
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cached = <_Cached*>self.mem.alloc(1, sizeof(_Cached))
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cached.length = len(substrings)
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cached.is_lex = False
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cached.data.tokens = tokens
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slice_unicode(&string, chunk, 0, len(chunk))
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self._specials.set(string.key, cached)
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self._cache.set(string.key, cached)
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