Source code for delphin.tokens


"""
YY tokens and token lattices.
"""

from typing import NamedTuple, Optional, List, Tuple
import re

from delphin.lnk import Lnk
# Default modules need to import the PyDelphin version
from delphin.__about__ import __version__  # noqa: F401


class _YYToken(NamedTuple):
    id: int
    start: int
    end: int
    lnk: Lnk
    paths: List[int]
    form: str
    surface: Optional[str]
    ipos: int          # relative index of sub-token to which lrules apply
    lrules: List[str]  # list of morphological rules applied, "null" if None
    pos: List[Tuple[str, float]]


[docs]class YYToken(_YYToken): """ A tuple of token data in the YY format. Args: id: token identifier start: start vertex end: end vertex lnk: <from:to> charspan (optional) paths: path membership form: surface token surface: original token (optional; only if `form` was modified) ipos: length of `lrules`? always 0? lrules: something about lexical rules; always "null"? pos: pairs of (POS, prob) """ __slots__ = () def __new__(cls, id, start, end, lnk=None, paths=(1,), form=None, surface=None, ipos=0, lrules=("null",), pos=()): if form is None: raise TypeError('Missing required keyword argument \'form\'.') if lnk is None: lnk = Lnk.default() return super(YYToken, cls).__new__( cls, id, start, end, lnk, list(paths), form, surface, ipos, list(lrules), list(pos) ) def __str__(self): parts = [str(self.id), str(self.start), str(self.end)] if self.lnk: parts.append(str(self.lnk)) parts.append(' '.join(map(str, self.paths or [1]))) if self.surface is None: parts.append(f'"{self.form}"') else: parts.append(f'"{self.form}" "{self.surface}"') parts.extend([ str(self.ipos), ' '.join(map('"{}"'.format, self.lrules)) ]) if self.pos: ps = [f'"{pos}" {p:.4f}' for pos, p in self.pos] parts.append(' '.join(ps)) return '({})'.format(', '.join(parts))
[docs] @classmethod def from_dict(cls, d): """ Decode from a dictionary as from :meth:`to_dict`. """ return cls( d['id'], d['start'], d['end'], Lnk.charspan(d['from'], d['to']) if 'from' in d else None, # d.get('paths', [1]), form=d['form'], surface=d.get('surface'), # ipos= # lrules= pos=list(zip(d.get('tags', []), d.get('probabilities', []))) )
[docs] def to_dict(self): """ Encode the token as a dictionary suitable for JSON serialization. """ d = { 'id': self.id, 'start': self.start, 'end': self.end, 'form': self.form } if self.lnk: cfrom, cto = self.lnk.data d['from'] = cfrom d['to'] = cto # d['paths'] = self.paths if self.surface is not None: d['surface'] = self.surface # d['ipos'] = self.ipos # d['lrules'] = self.lrules if self.pos: d['tags'] = [ps[0] for ps in self.pos] d['probabilities'] = [ps[1] for ps in self.pos] return d
# from: https://github.com/delph-in/docs/wiki/PetInput # (id, start, end, [link,] path+, form [surface], ipos, lrule+[, {pos p}+]) _yy_re = re.compile( r'\(\s*' r'(?P<id>{integer}){comma}' r'(?P<start>{integer}){comma}' r'(?P<end>{integer}){comma}' r'(?:<(?P<lnkfrom>{integer}):(?P<lnkto>{integer})>{comma})?' r'(?P<paths>(?:{integer}\s*)+){comma}' r'(?P<form>{string})' r'(?:\s*(?P<surface>{string}))?' r'{comma}' r'(?P<ipos>{integer}){comma}' r'(?P<lrules>(?:{string}\s*)+)' r'(?:{comma}(?P<pos>(?:{string}\s+{float}\s*)+))?' r'\s*\)' .format( integer=r'-?\d+', comma=r'\s*,\s*', string=r'"[^"\\]*(?:\\.[^"\\]*)*"', float=r'-?(0|[1-9]\d*)(\.\d+[eE][-+]?|\.|[eE][-+]?)\d+' ) )
[docs]class YYTokenLattice(object): """ A lattice of YY Tokens. Args: tokens: a list of YYToken objects """ def __init__(self, tokens): self.tokens = tokens
[docs] @classmethod def from_string(cls, s): """ Decode from the YY token lattice format. """ def _qstrip(s): return s[1:-1] # remove assumed quote characters tokens = [] for match in _yy_re.finditer(s): d = match.groupdict() lnk, pos = None, [] if d['lnkfrom'] is not None: lnk = Lnk.charspan(d['lnkfrom'], d['lnkto']) if d['pos'] is not None: ps = d['pos'].strip().split() pos = list(zip(map(_qstrip, ps[::2]), map(float, ps[1::2]))) tokens.append( YYToken( int(d['id']), int(d['start']), int(d['end']), lnk, list(map(int, d['paths'].strip().split())), _qstrip(d['form']), None if d['surface'] is None else _qstrip(d['surface']), int(d['ipos']), list(map(_qstrip, d['lrules'].strip().split())), pos ) ) return cls(tokens)
[docs] @classmethod def from_list(cls, toks): """ Decode from a list as from :meth:`to_list`. """ return cls(list(map(YYToken.from_dict, toks)))
[docs] def to_list(self): """ Encode the token lattice as a list suitable for JSON serialization. """ return [t.to_dict() for t in self.tokens]
def __str__(self): return ' '.join(map(str, self.tokens)) def __eq__(self, other): if not isinstance(other, YYTokenLattice): return NotImplemented if (len(self.tokens) == len(other.tokens) and all(t1 == t2 for t1, t2 in zip(self.tokens, other.tokens))): return True return False