spaCy/spacy/lang.pyx
2014-09-15 03:46:14 +02:00

329 lines
11 KiB
Cython

# cython: profile=True
# cython: embedsignature=True
"""Common classes and utilities across languages.
Provides the main implementation for the spacy tokenizer. Specific languages
subclass the Language class, over-writing the tokenization rules as necessary.
Special-case tokenization rules are read from data/<lang>/tokenization .
"""
from __future__ import unicode_literals
from libc.stdlib cimport calloc, free
import json
import random
from os import path
from .util import read_lang_data
from spacy.tokens import Tokens
from spacy.lexeme cimport LexemeC, lexeme_init
from murmurhash.mrmr cimport hash64
from cpython.ref cimport Py_INCREF
from spacy._hashing cimport PointerHash
from spacy import orth
from spacy import util
cdef enum Flags:
Flag_IsAlpha
Flag_IsAscii
Flag_IsDigit
Flag_IsLower
Flag_IsPunct
Flag_IsSpace
Flag_IsTitle
Flag_IsUpper
Flag_CanAdj
Flag_CanAdp
Flag_CanAdv
Flag_CanConj
Flag_CanDet
Flag_CanNoun
Flag_CanNum
Flag_CanPdt
Flag_CanPos
Flag_CanPron
Flag_CanPrt
Flag_CanPunct
Flag_CanVerb
Flag_OftLower
Flag_OftTitle
Flag_OftUpper
Flag_N
cdef enum Views:
View_CanonForm
View_WordShape
View_NonSparse
View_Asciied
View_N
# Assign the flag and view functions by enum value.
# This is verbose, but it ensures we don't get nasty order sensitivities.
STRING_VIEW_FUNCS = [None] * View_N
STRING_VIEW_FUNCS[View_CanonForm] = orth.canon_case
STRING_VIEW_FUNCS[View_WordShape] = orth.word_shape
STRING_VIEW_FUNCS[View_NonSparse] = orth.non_sparse
STRING_VIEW_FUNCS[View_Asciied] = orth.asciied
FLAG_FUNCS = [None] * Flag_N
FLAG_FUNCS[Flag_IsAlpha] = orth.is_alpha
FLAG_FUNCS[Flag_IsAscii] = orth.is_ascii
FLAG_FUNCS[Flag_IsDigit] = orth.is_digit
FLAG_FUNCS[Flag_IsLower] = orth.is_lower
FLAG_FUNCS[Flag_IsPunct] = orth.is_punct
FLAG_FUNCS[Flag_IsSpace] = orth.is_space
FLAG_FUNCS[Flag_IsTitle] = orth.is_title
FLAG_FUNCS[Flag_IsUpper] = orth.is_upper
FLAG_FUNCS[Flag_CanAdj] = orth.can_tag('ADJ')
FLAG_FUNCS[Flag_CanAdp] = orth.can_tag('ADP')
FLAG_FUNCS[Flag_CanAdv] = orth.can_tag('ADV')
FLAG_FUNCS[Flag_CanConj] = orth.can_tag('CONJ')
FLAG_FUNCS[Flag_CanDet] = orth.can_tag('DET')
FLAG_FUNCS[Flag_CanNoun] = orth.can_tag('NOUN')
FLAG_FUNCS[Flag_CanNum] = orth.can_tag('NUM')
FLAG_FUNCS[Flag_CanPdt] = orth.can_tag('PDT')
FLAG_FUNCS[Flag_CanPos] = orth.can_tag('POS')
FLAG_FUNCS[Flag_CanPron] = orth.can_tag('PRON')
FLAG_FUNCS[Flag_CanPrt] = orth.can_tag('PRT')
FLAG_FUNCS[Flag_CanPunct] = orth.can_tag('PUNCT')
FLAG_FUNCS[Flag_CanVerb] = orth.can_tag('VERB')
FLAG_FUNCS[Flag_OftLower] = orth.oft_case('lower', 0.7)
FLAG_FUNCS[Flag_OftTitle] = orth.oft_case('title', 0.7)
FLAG_FUNCS[Flag_OftUpper] = orth.oft_case('upper', 0.7)
cdef class Language:
"""Base class for language-specific tokenizers.
Most subclasses will override the _split or _split_one methods, which take
a string of non-whitespace characters and output a list of strings. This
function is called by _tokenize, which sits behind a cache and turns the
list of strings into Lexeme objects via the Lexicon. Most languages will not
need to override _tokenize or tokenize.
The language is supplied a list of boolean functions, used to compute flag
features. These are passed to the language's Lexicon object.
The language's name is used to look up default data-files, found in data/<name.
"""
fl_is_alpha = Flag_IsAlpha
fl_is_digit = Flag_IsDigit
v_shape = View_WordShape
def __cinit__(self, name, user_string_features, user_flag_features):
self.name = name
self.cache = PointerHash(2 ** 25)
self.specials = PointerHash(2 ** 16)
lang_data = util.read_lang_data(name)
rules, words, probs, clusters, case_stats, tag_stats = lang_data
self.lexicon = Lexicon(words, probs, clusters, case_stats, tag_stats,
STRING_VIEW_FUNCS + user_string_features,
FLAG_FUNCS + user_flag_features)
self._load_special_tokenization(rules)
def __dealloc__(self):
pass
property nr_types:
def __get__(self):
"""Return the number of lexical types in the vocabulary"""
return self.lexicon.size
cpdef Lexeme lookup(self, unicode string):
"""Retrieve (or create, if not found) a Lexeme for a string, and return it.
Args:
string (unicode): The string to be looked up. Must be unicode, not bytes.
Returns:
lexeme (Lexeme): A reference to a lexical type.
"""
return self.lexicon.lookup(string)
cpdef Tokens tokenize(self, unicode string):
"""Tokenize a string.
The tokenization rules are defined in two places:
* The data/<lang>/tokenization table, which handles special cases like contractions;
* The appropriate :py:meth:`find_split` function, which is used to split
off punctuation etc.
Args:
string (unicode): The string to be tokenized.
Returns:
tokens (Tokens): A Tokens object, giving access to a sequence of LexIDs.
"""
cdef size_t length = len(string)
cdef Tokens tokens = Tokens(length)
if length == 0:
return tokens
cdef size_t start = 0
cdef size_t i = 0
cdef Py_UNICODE* chars = string
cdef Py_UNICODE c
cdef String span
for i in range(length):
c = chars[i]
if Py_UNICODE_ISSPACE(c) == 1:
if start < i:
string_from_slice(&span, chars, start, i)
self._tokenize(tokens, &span)
start = i + 1
i += 1
if start < i:
string_from_slice(&span, chars, start, i)
self._tokenize(tokens, &span)
return tokens
cdef int _tokenize(self, Tokens tokens, String* string):
cdef LexemeC** lexemes = <LexemeC**>self.cache.get(string.key)
cdef size_t i
if lexemes != NULL:
i = 0
while lexemes[i] != NULL:
tokens.v.push_back(lexemes[i])
i += 1
return 0
cdef uint64_t key = string.key
cdef size_t first_token = len(tokens)
cdef int split
cdef int remaining = string.n
cdef String prefix
while remaining >= 1:
split = self._split_one(string.chars, string.n)
remaining -= split
string_slice_prefix(string, &prefix, split)
lexemes = <LexemeC**>self.specials.get(prefix.key)
if lexemes != NULL:
i = 0
while lexemes[i] != NULL:
tokens.v.push_back(lexemes[i])
i += 1
else:
tokens.v.push_back(<LexemeC*>self.lexicon.get(&prefix))
lexemes = <LexemeC**>calloc(len(tokens) - first_token, sizeof(LexemeC*))
cdef size_t j
for i, j in enumerate(range(first_token, tokens.v.size())):
lexemes[i] = tokens.v[0][j]
self.cache.set(key, lexemes)
cdef int _split_one(self, Py_UNICODE* characters, size_t length):
return length
def _load_special_tokenization(self, token_rules):
'''Load special-case tokenization rules.
Loads special-case tokenization rules into the Language.cache cache,
read from data/<lang>/tokenization . The special cases are loaded before
any language data is tokenized, giving these priority. For instance,
the English tokenization rules map "ain't" to ["are", "not"].
Args:
token_rules (list): A list of (chunk, tokens) pairs, where chunk is
a string and tokens is a list of strings.
'''
cdef LexemeC** lexemes
cdef uint64_t hashed
cdef String string
for uni_string, substrings in token_rules:
lexemes = <LexemeC**>calloc(len(substrings) + 1, sizeof(LexemeC*))
for i, substring in enumerate(substrings):
string_from_unicode(&string, substring)
lexemes[i] = <LexemeC*>self.lexicon.get(&string)
lexemes[i + 1] = NULL
string_from_unicode(&string, uni_string)
self.specials.set(string.key, lexemes)
self.cache.set(string.key, lexemes)
cdef class Lexicon:
def __cinit__(self, words, probs, clusters, case_stats, tag_stats,
string_features, flag_features):
self._flag_features = flag_features
self._string_features = string_features
self._dict = PointerHash(2 ** 20)
self.size = 0
cdef String string
for uni_string in words:
prob = probs.get(uni_string, 0.0)
cluster = clusters.get(uni_string, 0.0)
cases = case_stats.get(uni_string, {})
tags = tag_stats.get(uni_string, {})
views = [string_view(uni_string, prob, cluster, cases, tags)
for string_view in self._string_features]
flags = set()
for i, flag_feature in enumerate(self._flag_features):
if flag_feature(uni_string, prob, cluster, cases, tags):
flags.add(i)
lexeme = lexeme_init(uni_string, prob, cluster, views, flags)
string_from_unicode(&string, uni_string)
self._dict.set(string.key, lexeme)
self.size += 1
cdef LexemeC* get(self, String* string):
cdef LexemeC* lexeme
lexeme = <LexemeC*>self._dict.get(string.key)
if lexeme != NULL:
return lexeme
cdef unicode uni_string = string.chars[:string.n]
views = [string_view(uni_string, 0.0, 0, {}, {})
for string_view in self._string_features]
flags = set()
for i, flag_feature in enumerate(self._flag_features):
if flag_feature(uni_string, 0.0, {}, {}):
flags.add(i)
lexeme = lexeme_init(uni_string, 0, 0, views, flags)
self._dict.set(string.key, lexeme)
self.size += 1
return lexeme
cpdef Lexeme lookup(self, unicode uni_string):
"""Retrieve (or create, if not found) a Lexeme for a string, and return it.
Args
string (unicode): The string to be looked up. Must be unicode, not bytes.
Returns:
lexeme (Lexeme): A reference to a lexical type.
"""
cdef String string
string_from_unicode(&string, uni_string)
cdef LexemeC* lexeme = self.get(&string)
return Lexeme(<size_t>lexeme)
cdef void string_from_unicode(String* s, unicode uni):
Py_INCREF(uni)
cdef Py_UNICODE* c_uni = <Py_UNICODE*>uni
string_from_slice(s, c_uni, 0, len(uni))
cdef inline void string_from_slice(String* s, Py_UNICODE* chars, size_t start, size_t end) nogil:
s.chars = &chars[start]
s.n = end - start
s.key = hash64(s.chars, s.n * sizeof(Py_UNICODE), 0)
cdef inline void string_slice_prefix(String* s, String* prefix, size_t n) nogil:
string_from_slice(prefix, s.chars, 0, n)
s.chars += n
s.n -= n
s.key = hash64(s.chars, s.n * sizeof(Py_UNICODE), 0)