From 1bb87f35bc5babbfc2969737100a2acffab74675 Mon Sep 17 00:00:00 2001 From: kadarakos Date: Wed, 8 Jun 2022 19:34:11 +0200 Subject: [PATCH] Detect cycle during projectivize (#10877) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * detect cycle during projectivize * not complete test to detect cycle in projectivize * boolean to int type to propagate error * use unordered_set instead of set * moved error message to errors * removed cycle from test case * use find instead of count * cycle check: only perform one lookup * Return bool again from _has_head_as_ancestor Communicate presence of cycles through an output argument. * Switch to returning std::pair to encode presence of a cycle The has_cycle pointer is too easy to misuse. Ideally, we would have a sum type like Rust's `Result` here, but C++ is not there yet. * _is_non_proj_arc: clarify what we are returning * _has_head_as_ancestor: remove count We are now explicitly checking for cycles, so the algorithm must always terminate. Either we encounter the head, we find a root, or a cycle. * _is_nonproj_arc: simplify condition * Another refactor using C++ exceptions * Remove unused error code * Print graph with cycle on exception * Include .hh files in source package * Add FIXME comment * cycle detection test * find cycle when starting from problematic vertex Co-authored-by: Danièˆl de Kok --- MANIFEST.in | 2 +- spacy/pipeline/_parser_internals/nonproj.hh | 11 +++++ spacy/pipeline/_parser_internals/nonproj.pxd | 4 ++ spacy/pipeline/_parser_internals/nonproj.pyx | 48 ++++++++++++++++---- spacy/tests/parser/test_nonproj.py | 12 ++++- spacy/tests/training/test_training.py | 6 +-- 6 files changed, 67 insertions(+), 16 deletions(-) create mode 100644 spacy/pipeline/_parser_internals/nonproj.hh diff --git a/MANIFEST.in b/MANIFEST.in index b7826e456..8ded6f808 100644 --- a/MANIFEST.in +++ b/MANIFEST.in @@ -1,4 +1,4 @@ -recursive-include spacy *.pyi *.pyx *.pxd *.txt *.cfg *.jinja *.toml +recursive-include spacy *.pyi *.pyx *.pxd *.txt *.cfg *.jinja *.toml *.hh include LICENSE include README.md include pyproject.toml diff --git a/spacy/pipeline/_parser_internals/nonproj.hh b/spacy/pipeline/_parser_internals/nonproj.hh new file mode 100644 index 000000000..071fd57b4 --- /dev/null +++ b/spacy/pipeline/_parser_internals/nonproj.hh @@ -0,0 +1,11 @@ +#ifndef NONPROJ_HH +#define NONPROJ_HH + +#include +#include + +void raise_domain_error(std::string const &msg) { + throw std::domain_error(msg); +} + +#endif // NONPROJ_HH diff --git a/spacy/pipeline/_parser_internals/nonproj.pxd b/spacy/pipeline/_parser_internals/nonproj.pxd index e69de29bb..aabdf7ebe 100644 --- a/spacy/pipeline/_parser_internals/nonproj.pxd +++ b/spacy/pipeline/_parser_internals/nonproj.pxd @@ -0,0 +1,4 @@ +from libcpp.string cimport string + +cdef extern from "nonproj.hh": + cdef void raise_domain_error(const string& msg) nogil except + diff --git a/spacy/pipeline/_parser_internals/nonproj.pyx b/spacy/pipeline/_parser_internals/nonproj.pyx index 36163fcc3..d1b6e7066 100644 --- a/spacy/pipeline/_parser_internals/nonproj.pyx +++ b/spacy/pipeline/_parser_internals/nonproj.pyx @@ -4,10 +4,13 @@ for doing pseudo-projective parsing implementation uses the HEAD decoration scheme. """ from copy import copy +from cython.operator cimport preincrement as incr, dereference as deref from libc.limits cimport INT_MAX from libc.stdlib cimport abs from libcpp cimport bool +from libcpp.string cimport string, to_string from libcpp.vector cimport vector +from libcpp.unordered_set cimport unordered_set from ...tokens.doc cimport Doc, set_children_from_heads @@ -49,7 +52,7 @@ def is_nonproj_arc(tokenid, heads): return _is_nonproj_arc(tokenid, c_heads) -cdef bool _is_nonproj_arc(int tokenid, const vector[int]& heads) nogil: +cdef bool _is_nonproj_arc(int tokenid, const vector[int]& heads) nogil except *: # definition (e.g. Havelka 2007): an arc h -> d, h < d is non-projective # if there is a token k, h < k < d such that h is not # an ancestor of k. Same for h -> d, h > d @@ -58,32 +61,56 @@ cdef bool _is_nonproj_arc(int tokenid, const vector[int]& heads) nogil: return False elif head < 0: # unattached tokens cannot be non-projective return False - + cdef int start, end if head < tokenid: start, end = (head+1, tokenid) else: start, end = (tokenid+1, head) for k in range(start, end): - if _has_head_as_ancestor(k, head, heads): - continue - else: # head not in ancestors: d -> h is non-projective + if not _has_head_as_ancestor(k, head, heads): return True return False -cdef bool _has_head_as_ancestor(int tokenid, int head, const vector[int]& heads) nogil: +cdef bool _has_head_as_ancestor(int tokenid, int head, const vector[int]& heads) nogil except *: ancestor = tokenid - cnt = 0 - while cnt < heads.size(): + cdef unordered_set[int] seen_tokens + seen_tokens.insert(ancestor) + while True: + # Reached the head or a disconnected node if heads[ancestor] == head or heads[ancestor] < 0: return True + # Reached the root + if heads[ancestor] == ancestor: + return False ancestor = heads[ancestor] - cnt += 1 + result = seen_tokens.insert(ancestor) + # Found cycle + if not result.second: + raise_domain_error(heads_to_string(heads)) return False +cdef string heads_to_string(const vector[int]& heads) nogil: + cdef vector[int].const_iterator citer + cdef string cycle_str + + cycle_str.append("Found cycle in dependency graph: [") + + # FIXME: Rewrite using ostringstream when available in Cython. + citer = heads.const_begin() + while citer != heads.const_end(): + if citer != heads.const_begin(): + cycle_str.append(", ") + cycle_str.append(to_string(deref(citer))) + incr(citer) + cycle_str.append("]") + + return cycle_str + + def is_nonproj_tree(heads): cdef vector[int] c_heads = _heads_to_c(heads) # a tree is non-projective if at least one arc is non-projective @@ -176,11 +203,12 @@ def get_smallest_nonproj_arc_slow(heads): return _get_smallest_nonproj_arc(c_heads) -cdef int _get_smallest_nonproj_arc(const vector[int]& heads) nogil: +cdef int _get_smallest_nonproj_arc(const vector[int]& heads) nogil except -2: # return the smallest non-proj arc or None # where size is defined as the distance between dep and head # and ties are broken left to right cdef int smallest_size = INT_MAX + # -1 means its already projective. cdef int smallest_np_arc = -1 cdef int size cdef int tokenid diff --git a/spacy/tests/parser/test_nonproj.py b/spacy/tests/parser/test_nonproj.py index 60d000c44..b420c300f 100644 --- a/spacy/tests/parser/test_nonproj.py +++ b/spacy/tests/parser/test_nonproj.py @@ -49,7 +49,7 @@ def test_parser_contains_cycle(tree, cyclic_tree, partial_tree, multirooted_tree assert contains_cycle(multirooted_tree) is None -def test_parser_is_nonproj_arc(nonproj_tree, partial_tree, multirooted_tree): +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 @@ -62,15 +62,19 @@ def test_parser_is_nonproj_arc(nonproj_tree, partial_tree, multirooted_tree): 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, nonproj_tree, partial_tree, multirooted_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): @@ -84,8 +88,10 @@ def test_parser_pseudoprojectivity(en_vocab): 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", "") @@ -97,6 +103,8 @@ def test_parser_pseudoprojectivity(en_vocab): 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"] diff --git a/spacy/tests/training/test_training.py b/spacy/tests/training/test_training.py index 8e08a25fb..31bf7e07b 100644 --- a/spacy/tests/training/test_training.py +++ b/spacy/tests/training/test_training.py @@ -671,13 +671,13 @@ def test_gold_ner_missing_tags(en_tokenizer): def test_projectivize(en_tokenizer): doc = en_tokenizer("He pretty quickly walks away") - heads = [3, 2, 3, 0, 2] + heads = [3, 2, 3, 3, 2] deps = ["dep"] * len(heads) example = Example.from_dict(doc, {"heads": heads, "deps": deps}) proj_heads, proj_labels = example.get_aligned_parse(projectivize=True) nonproj_heads, nonproj_labels = example.get_aligned_parse(projectivize=False) - assert proj_heads == [3, 2, 3, 0, 3] - assert nonproj_heads == [3, 2, 3, 0, 2] + assert proj_heads == [3, 2, 3, 3, 3] + assert nonproj_heads == [3, 2, 3, 3, 2] def test_iob_to_biluo():