Revert "Remove Span._recalculate_indices"

This reverts commit 727370c633.

spacy/tests/doc/test_doc_api.py

@@ -608,11 +608,14 @@ def test_doc_init_iob():
         doc = Doc(Vocab(), words=words, ents=ents)
 
 
-def test_doc_set_ents_invalid_spans(en_tokenizer):
+@pytest.mark.xfail
+def test_doc_set_ents_spans(en_tokenizer):
     doc = en_tokenizer("Some text about Colombia and the Czech Republic")
     spans = [Span(doc, 3, 4, label="GPE"), Span(doc, 6, 8, label="GPE")]
     with doc.retokenize() as retokenizer:
         for span in spans:
             retokenizer.merge(span)
-    with pytest.raises(IndexError):
+    # If this line is uncommented, it works:
+    # print(spans)
     doc.ents = spans
+    assert [ent.text for ent in doc.ents] == ["Colombia", "Czech Republic"]

spacy/tests/doc/test_retokenize_merge.py

@@ -336,7 +336,6 @@ def test_doc_retokenize_spans_sentence_update_after_merge(en_tokenizer):
         attrs = {"lemma": "none", "ent_type": "none"}
         retokenizer.merge(doc[0:2], attrs=attrs)
         retokenizer.merge(doc[-2:], attrs=attrs)
-    sent1, sent2 = list(doc.sents)
     assert len(sent1) == init_len - 1
     assert len(sent2) == init_len2 - 1
 

spacy/tokens/span.pxd

@@ -16,4 +16,5 @@ cdef class Span:
     cdef public _vector
     cdef public _vector_norm
 
+    cpdef int _recalculate_indices(self) except -1
     cpdef np.ndarray to_array(self, object features)

spacy/tokens/span.pyx

@@ -150,6 +150,7 @@ cdef class Span:
 
         DOCS: https://nightly.spacy.io/api/span#len
         """
+        self._recalculate_indices()
         if self.end < self.start:
             return 0
         return self.end - self.start
@@ -166,6 +167,7 @@ cdef class Span:
 
         DOCS: https://nightly.spacy.io/api/span#getitem
         """
+        self._recalculate_indices()
         if isinstance(i, slice):
             start, end = normalize_slice(len(self), i.start, i.stop, i.step)
             return Span(self.doc, start + self.start, end + self.start)
@@ -186,6 +188,7 @@ cdef class Span:
 
         DOCS: https://nightly.spacy.io/api/span#iter
         """
+        self._recalculate_indices()
         for i in range(self.start, self.end):
             yield self.doc[i]
 
@@ -336,6 +339,19 @@ cdef class Span:
                 output[i-self.start, j] = get_token_attr(&self.doc.c[i], feature)
         return output
 
+    cpdef int _recalculate_indices(self) except -1:
+        if self.end > self.doc.length \
+        or self.doc.c[self.start].idx != self.start_char \
+        or (self.doc.c[self.end-1].idx + self.doc.c[self.end-1].lex.length) != self.end_char:
+            start = token_by_start(self.doc.c, self.doc.length, self.start_char)
+            if self.start == -1:
+                raise IndexError(Errors.E036.format(start=self.start_char))
+            end = token_by_end(self.doc.c, self.doc.length, self.end_char)
+            if end == -1:
+                raise IndexError(Errors.E037.format(end=self.end_char))
+            self.start = start
+            self.end = end + 1
+
     @property
     def vocab(self):
         """RETURNS (Vocab): The Span's Doc's vocab."""
@@ -504,6 +520,7 @@ cdef class Span:
 
         DOCS: https://nightly.spacy.io/api/span#root
         """
+        self._recalculate_indices()
         if "root" in self.doc.user_span_hooks:
             return self.doc.user_span_hooks["root"](self)
         # This should probably be called 'head', and the other one called