spaCy/spacy/tests/parser/test_nonproj.py

import pytest

from spacy.pipeline._parser_internals import nonproj
from spacy.pipeline._parser_internals.nonproj import (
    ancestors,
    contains_cycle,
    is_nonproj_arc,
    is_nonproj_tree,
)
from spacy.tokens import Doc


@pytest.fixture
def tree():
    return [1, 2, 2, 4, 5, 2, 2]


@pytest.fixture
def cyclic_tree():
    return [1, 2, 2, 4, 5, 3, 2]


@pytest.fixture
def partial_tree():
    return [1, 2, 2, 4, 5, None, 7, 4, 2]


@pytest.fixture
def nonproj_tree():
    return [1, 2, 2, 4, 5, 2, 7, 4, 2]


@pytest.fixture
def proj_tree():
    return [1, 2, 2, 4, 5, 2, 7, 5, 2]


@pytest.fixture
def multirooted_tree():
    return [3, 2, 0, 3, 3, 7, 7, 3, 7, 10, 7, 10, 11, 12, 18, 16, 18, 17, 12, 3]


def test_parser_ancestors(tree, cyclic_tree, partial_tree, multirooted_tree):
    assert [a for a in ancestors(3, tree)] == [4, 5, 2]
    assert [a for a in ancestors(3, cyclic_tree)] == [4, 5, 3, 4, 5, 3, 4]
    assert [a for a in ancestors(3, partial_tree)] == [4, 5, None]
    assert [a for a in ancestors(17, multirooted_tree)] == []


def test_parser_contains_cycle(tree, cyclic_tree, partial_tree, multirooted_tree):
    assert contains_cycle(tree) is None
    assert contains_cycle(cyclic_tree) == {3, 4, 5}
    assert contains_cycle(partial_tree) is None
    assert contains_cycle(multirooted_tree) is None


def test_parser_is_nonproj_arc(
    cyclic_tree, nonproj_tree, partial_tree, multirooted_tree
):
    assert is_nonproj_arc(0, nonproj_tree) is False
    assert is_nonproj_arc(1, nonproj_tree) is False
    assert is_nonproj_arc(2, nonproj_tree) is False
    assert is_nonproj_arc(3, nonproj_tree) is False
    assert is_nonproj_arc(4, nonproj_tree) is False
    assert is_nonproj_arc(5, nonproj_tree) is False
    assert is_nonproj_arc(6, nonproj_tree) is False
    assert is_nonproj_arc(7, nonproj_tree) is True
    assert is_nonproj_arc(8, nonproj_tree) is False
    assert is_nonproj_arc(7, partial_tree) is False
    assert is_nonproj_arc(17, multirooted_tree) is False
    assert is_nonproj_arc(16, multirooted_tree) is True
    with pytest.raises(
        ValueError, match=r"Found cycle in dependency graph: \[1, 2, 2, 4, 5, 3, 2\]"
    ):
        is_nonproj_arc(6, cyclic_tree)


def test_parser_is_nonproj_tree(
    proj_tree, cyclic_tree, nonproj_tree, partial_tree, multirooted_tree
):
    assert is_nonproj_tree(proj_tree) is False
    assert is_nonproj_tree(nonproj_tree) is True
    assert is_nonproj_tree(partial_tree) is False
    assert is_nonproj_tree(multirooted_tree) is True
    with pytest.raises(
        ValueError, match=r"Found cycle in dependency graph: \[1, 2, 2, 4, 5, 3, 2\]"
    ):
        is_nonproj_tree(cyclic_tree)


def test_parser_pseudoprojectivity(en_vocab):
    def deprojectivize(proj_heads, deco_labels):
        words = ["whatever "] * len(proj_heads)
        doc = Doc(en_vocab, words=words, deps=deco_labels, heads=proj_heads)
        nonproj.deprojectivize(doc)
        return [t.head.i for t in doc], [token.dep_ for token in doc]

    # fmt: off
    tree = [1, 2, 2]
    nonproj_tree = [1, 2, 2, 4, 5, 2, 7, 4, 2]
    nonproj_tree2 = [9, 1, 3, 1, 5, 6, 9, 8, 6, 1, 6, 12, 13, 10, 1]
    cyclic_tree = [1, 2, 2, 4, 5, 3, 2]
    labels = ["det", "nsubj", "root", "det", "dobj", "aux", "nsubj", "acl", "punct"]
    labels2 = ["advmod", "root", "det", "nsubj", "advmod", "det", "dobj", "det", "nmod", "aux", "nmod", "advmod", "det", "amod", "punct"]
    cyclic_labels = ["det", "nsubj", "root", "det", "dobj", "aux", "punct"]
    # fmt: on
    assert nonproj.decompose("X||Y") == ("X", "Y")
    assert nonproj.decompose("X") == ("X", "")
    assert nonproj.is_decorated("X||Y") is True
    assert nonproj.is_decorated("X") is False
    nonproj._lift(0, tree)
    assert tree == [2, 2, 2]
    assert nonproj.get_smallest_nonproj_arc_slow(nonproj_tree) == 7
    assert nonproj.get_smallest_nonproj_arc_slow(nonproj_tree2) == 10
    # fmt: off
    proj_heads, deco_labels = nonproj.projectivize(nonproj_tree, labels)
    with pytest.raises(ValueError, match=r'Found cycle in dependency graph: \[1, 2, 2, 4, 5, 3, 2\]'):
        nonproj.projectivize(cyclic_tree, cyclic_labels)
    assert proj_heads == [1, 2, 2, 4, 5, 2, 7, 5, 2]
    assert deco_labels == ["det", "nsubj", "root", "det", "dobj", "aux",
                           "nsubj", "acl||dobj", "punct"]
    deproj_heads, undeco_labels = deprojectivize(proj_heads, deco_labels)
    assert deproj_heads == nonproj_tree
    assert undeco_labels == labels
    proj_heads, deco_labels = nonproj.projectivize(nonproj_tree2, labels2)
    assert proj_heads == [1, 1, 3, 1, 5, 6, 9, 8, 6, 1, 9, 12, 13, 10, 1]
    assert deco_labels == ["advmod||aux", "root", "det", "nsubj", "advmod",
                           "det", "dobj", "det", "nmod", "aux", "nmod||dobj",
                           "advmod", "det", "amod", "punct"]
    deproj_heads, undeco_labels = deprojectivize(proj_heads, deco_labels)
    assert deproj_heads == nonproj_tree2
    assert undeco_labels == labels2
    # if decoration is wrong such that there is no head with the desired label
    # the structure is kept and the label is undecorated
    proj_heads = [1, 2, 2, 4, 5, 2, 7, 5, 2]
    deco_labels = ["det", "nsubj", "root", "det", "dobj", "aux", "nsubj",
                   "acl||iobj", "punct"]
    deproj_heads, undeco_labels = deprojectivize(proj_heads, deco_labels)
    assert deproj_heads == proj_heads
    assert undeco_labels == ["det", "nsubj", "root", "det", "dobj", "aux",
                             "nsubj", "acl", "punct"]
    # if there are two potential new heads, the first one is chosen even if
    # it's wrong
    proj_heads = [1, 1, 3, 1, 5, 6, 9, 8, 6, 1, 9, 12, 13, 10, 1]
    deco_labels = ["advmod||aux", "root", "det", "aux", "advmod", "det",
                   "dobj", "det", "nmod", "aux", "nmod||dobj", "advmod",
                   "det", "amod", "punct"]

    deproj_heads, undeco_labels = deprojectivize(proj_heads, deco_labels)
    assert deproj_heads == [3, 1, 3, 1, 5, 6, 9, 8, 6, 1, 6, 12, 13, 10, 1]
    assert undeco_labels == ["advmod", "root", "det", "aux", "advmod", "det",
                             "dobj", "det", "nmod", "aux", "nmod", "advmod",
                             "det", "amod", "punct"]
    # fmt: on