spaCy/spacy/lang.pyx
2014-09-26 18:40:03 +02:00

430 lines
15 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
import json
import random
from os import path
import re
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 cymem.cymem cimport Pool
from cython.operator cimport preincrement as preinc
from cython.operator cimport dereference as deref
from preshed.maps cimport PreshMap
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._mem = Pool()
self.cache = PreshMap(2 ** 25)
self.specials = PreshMap(2 ** 16)
lang_data = util.read_lang_data(name)
rules, prefix, suffix, words, probs, clusters, case_stats, tag_stats = lang_data
self.prefix_re = re.compile(prefix)
self.suffix_re = re.compile(suffix)
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)
try:
self._tokenize(tokens.v, &span)
except MemoryError:
print chars[start:i]
raise
start = i + 1
i += 1
if start < i:
string_from_slice(&span, chars, start, i)
self._tokenize(tokens.v, &span)
return tokens
cdef int _tokenize(self, vector[LexemeC*] *tokens_v, String* string) except -1:
cdef size_t i
lexemes = <LexemeC**>self.cache.get(string.key)
if lexemes != NULL:
i = 0
while lexemes[i] != NULL:
tokens_v.push_back(lexemes[i])
i += 1
return 0
cdef uint64_t orig_key = string.key
cdef size_t orig_size = tokens_v.size()
cdef vector[LexemeC*] prefixes
cdef vector[LexemeC*] suffixes
cdef String prefix
cdef String suffix
cdef String minus_pre
cdef String minus_suf
cdef size_t last_size = 0
while string.n != 0 and string.n != last_size:
last_size = string.n
pre_len = self._find_prefix(string.chars, string.n)
if pre_len != 0:
string_from_slice(&prefix, string.chars, 0, pre_len)
string_from_slice(&minus_pre, string.chars, pre_len, string.n)
# Check whether we've hit a special-case
if minus_pre.n >= 1 and self.specials.get(minus_pre.key) != NULL:
string = &minus_pre
prefixes.push_back(self.lexicon.get(&prefix))
break
suf_len = self._find_suffix(string.chars, string.n)
if suf_len != 0:
string_from_slice(&suffix, string.chars, string.n - suf_len, string.n)
string_from_slice(&minus_suf, string.chars, 0, string.n - suf_len)
# Check whether we've hit a special-case
if minus_suf.n >= 1 and self.specials.get(minus_suf.key) != NULL:
string = &minus_suf
suffixes.push_back(self.lexicon.get(&suffix))
break
if pre_len and suf_len and (pre_len + suf_len) <= string.n:
string_from_slice(string, string.chars, pre_len, string.n - suf_len)
prefixes.push_back(self.lexicon.get(&prefix))
suffixes.push_back(self.lexicon.get(&suffix))
elif pre_len:
string = &minus_pre
prefixes.push_back(self.lexicon.get(&prefix))
elif suf_len:
string = &minus_suf
suffixes.push_back(self.lexicon.get(&suffix))
if self.specials.get(string.key):
break
self._attach_tokens(tokens_v, string, &prefixes, &suffixes)
self._save_cached(tokens_v, orig_key, orig_size)
cdef int _check_cache(self, vector[LexemeC*] *tokens, String* string) except -1:
lexemes = <LexemeC**>self.cache.get(string.key)
cdef size_t i = 0
if lexemes != NULL:
while lexemes[i] != NULL:
tokens.push_back(lexemes[i])
i += 1
string.n = 0
string.key = 0
string.chars = NULL
cdef int _attach_tokens(self, vector[LexemeC*] *tokens, String* string,
vector[LexemeC*] *prefixes,
vector[LexemeC*] *suffixes) except -1:
cdef size_t i
cdef LexemeC** lexemes
cdef LexemeC* lexeme
for lexeme in deref(prefixes):
tokens.push_back(lexeme)
if string.n != 0:
lexemes = <LexemeC**>self.specials.get(string.key)
if lexemes != NULL:
i = 0
while lexemes[i] != NULL:
tokens.push_back(lexemes[i])
i += 1
else:
tokens.push_back(self.lexicon.get(string))
cdef vector[LexemeC*].reverse_iterator it = suffixes.rbegin()
while it != suffixes.rend():
tokens.push_back(deref(it))
preinc(it)
cdef int _save_cached(self, vector[LexemeC*] *tokens,
uint64_t key, size_t n) except -1:
assert tokens.size() > n
lexemes = <LexemeC**>self._mem.alloc((tokens.size() - n) + 1, sizeof(LexemeC**))
cdef size_t i, j
for i, j in enumerate(range(n, tokens.size())):
lexemes[i] = tokens.at(j)
lexemes[i + 1] = NULL
self.cache.set(key, lexemes)
cdef int _find_prefix(self, Py_UNICODE* chars, size_t length) except -1:
cdef unicode string = chars[:length]
match = self.prefix_re.search(string)
if match is None:
return 0
else:
return match.end() - match.start()
cdef int _find_suffix(self, Py_UNICODE* chars, size_t length):
cdef unicode string = chars[:length]
match = self.suffix_re.search(string)
if match is None:
return 0
else:
return match.end() - match.start()
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**>self._mem.alloc(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._mem = Pool()
self._flag_features = flag_features
self._string_features = string_features
self._dict = PreshMap(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(self._mem, 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) except NULL:
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(self._mem, 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):
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)
cdef inline void string_slice_suffix(String* s, String* suffix, size_t n) nogil:
string_from_slice(suffix, s.chars, s.n - n, s.n)
s.n -= n
s.key = hash64(s.chars, s.n * sizeof(Py_UNICODE), 0)