def buildStackByGlueRule(self, supportLattice1, supportLattice2):
"""
Build a pseudo lattice stack by given two support latice items.
Output:
[(
"translation", [supportLattice1,supportLattice2],
[COSTSUM - 10 * 6],
score
)]
"""
# Check availibility of support lattice.
if supportLattice1 not in self.mapLattice or supportLattice2 not in self.mapLattice:
return None
ntSpan = [supportLattice1, supportLattice2]
translation = "[X0] [X1]"
# Check if one of the two support lattice is original site.
glueRule = (translation, ntSpan, GLUECOST)
simplePruner = SimpleCubePruner(self.model, [glueRule], ntSpan, self.mapLattice)
stack = simplePruner.prune()
# Prune with beam size.
stack = stack[:self.beamSize]
return stack
def buildSCFGStack(self, begin, width):
"""
Build stack of non lexical lattice items.
"""
stack = []
# Find all combinations of all support or inferred items.
combs = self.findAllInferredCombinations(begin, width)
for comb in combs:
rulesFound, ntSpanList = self.fetchRulesForComb(comb)
if not rulesFound:
continue
# Merge products.
simplePruner = SimpleCubePruner(self.model, rulesFound, ntSpanList, self.mapLattice)
hyps = simplePruner.prune()
# Prune with beam size.
hyps = hyps[:self.beamSize]
stack.extend(hyps)
# If not found, then return None
if not stack:
return None
# Only leave highest score of same translation.
mapTranslationBestScore = {}
for hyp in stack:
translation = hyp[0]
score = hyp[-2]
if (translation not in mapTranslationBestScore or
score > mapTranslationBestScore[translation]):
mapTranslationBestScore[translation] = score
idx = 0
while idx < len(stack):
hyp = stack[idx]
if hyp[-2] < mapTranslationBestScore[hyp[0]]:
stack.pop(idx)
else:
idx += 1
# Sort and prune.
return self.sortStack(stack)
