diff options
Diffstat (limited to 'Lib/difflib.py')
| -rw-r--r-- | Lib/difflib.py | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/Lib/difflib.py b/Lib/difflib.py index 3558f53836..55f69bac79 100644 --- a/Lib/difflib.py +++ b/Lib/difflib.py @@ -473,27 +473,32 @@ class SequenceMatcher: if self.matching_blocks is not None: return self.matching_blocks - self.matching_blocks = [] la, lb = len(self.a), len(self.b) - self.__helper(0, la, 0, lb, self.matching_blocks) + + indexed_blocks = [] + queue = [(0, la, 0, lb)] + while queue: + # builds list of matching blocks covering a[alo:ahi] and + # b[blo:bhi], appending them in increasing order to answer + alo, ahi, blo, bhi = queue.pop() + + # a[alo:i] vs b[blo:j] unknown + # a[i:i+k] same as b[j:j+k] + # a[i+k:ahi] vs b[j+k:bhi] unknown + i, j, k = x = self.find_longest_match(alo, ahi, blo, bhi) + + if k: + if alo < i and blo < j: + queue.append((alo, i, blo, j)) + indexed_blocks.append((i, x)) + if i+k < ahi and j+k < bhi: + queue.append((i+k, ahi, j+k, bhi)) + indexed_blocks.sort() + + self.matching_blocks = [elem[1] for elem in indexed_blocks] self.matching_blocks.append( (la, lb, 0) ) return self.matching_blocks - # builds list of matching blocks covering a[alo:ahi] and - # b[blo:bhi], appending them in increasing order to answer - - def __helper(self, alo, ahi, blo, bhi, answer): - i, j, k = x = self.find_longest_match(alo, ahi, blo, bhi) - # a[alo:i] vs b[blo:j] unknown - # a[i:i+k] same as b[j:j+k] - # a[i+k:ahi] vs b[j+k:bhi] unknown - if k: - if alo < i and blo < j: - self.__helper(alo, i, blo, j, answer) - answer.append(x) - if i+k < ahi and j+k < bhi: - self.__helper(i+k, ahi, j+k, bhi, answer) - def get_opcodes(self): """Return list of 5-tuples describing how to turn a into b. |