query results can now be sorted and pruned

contrib/python/binpt/binpt.pyx

@@ -1,6 +1,11 @@
 from libcpp.string cimport string
 from libcpp.vector cimport vector
 import os
+import cython
+
+cpdef int fsign(float x):
+    '''Simply returns the sign of float x (zero is assumed +), it's defined here just so one gains a little bit with static typing'''
+    return 1 if x >= 0 else -1
 
 cdef bytes as_str(data):
     if isinstance(data, bytes):
@@ -43,6 +48,13 @@ cdef class QueryResult(object):
         '''Word-alignment info (as string)'''
         return self._wa
 
+    @staticmethod
+    def desc(x, y, keys = lambda r: r.scores[0]):
+        '''Returns the sign of keys(y) - keys(x).
+        Can only be used if scores is not an empty vector as
+        keys defaults to scores[0]'''
+        return fsign(keys(y) - keys(x))
+
     def __str__(self):
         '''Returns a string such as: <words> ||| <scores> [||| word-alignment info]'''
         if self._wa:
@@ -126,14 +138,16 @@ cdef class BinaryPhraseTable(object):
     def delimiters(self):
         return self._delimiters
 
-    def query(self, line):
+    def query(self, line, cmp = None, top = 0):
         '''Queries the phrase table and returns a list of matches.
-        Each match is a QueryResult.'''
+        Each match is a QueryResult.
+        If 'cmp' is defined the return list is sorted.
+        If 'top' is defined, onlye the top elements will be returned.'''
         cdef bytes text = as_str(line)
         cdef vector[string] fphrase = Tokenize(string(text), string(self._delimiters))
         cdef vector[StringTgtCand]* rv = new vector[StringTgtCand]()
         cdef vector[string]* wa = NULL
-        
+        cdef list phrases
         if not self.__tree.UseWordAlignment():
             self.__tree.GetTargetCandidates(fphrase, rv[0])
             phrases = [get_query_result(rv[0][i]) for i in range(rv.size())]
@@ -143,5 +157,10 @@ cdef class BinaryPhraseTable(object):
             phrases = [get_query_result(rv[0][i], wa[0][i].c_str()) for i in range(rv.size())]
             del wa
         del rv
-        return phrases
+        if cmp:
+            phrases.sort(cmp=cmp)
+        if top > 0:
+            return phrases[0:top]
+        else:  
+            return phrases
         

contrib/python/example.py

@@ -1,8 +1,8 @@
-from binpt import BinaryPhraseTable
+import binpt
 #from binpt import QueryResult
-
 import sys
 
+
 if len(sys.argv) < 3:
     print "Usage: %s phrase-table nscores [wa] < query > result" % (sys.argv[0])
     sys.exit(0)
@@ -11,12 +11,12 @@ pt_file = sys.argv[1]
 nscores = int(sys.argv[2])
 wa = len(sys.argv) == 4
 
-pt = BinaryPhraseTable(pt_file, nscores, wa)
+pt = binpt.BinaryPhraseTable(pt_file, nscores, wa)
 print >> sys.stderr, "-ttable %s -nscores %d -alignment-info %s -delimiter '%s'\n" %(pt.path, pt.nscores, str(pt.wa), pt.delimiters)
 
 for line in sys.stdin:
     f = line.strip()
-    matches = pt.query(f)
+    matches = pt.query(f, cmp = binpt.QueryResult.desc, top = 20)
     print '\n'.join([' ||| '.join((f, str(e))) for e in matches])
     '''
     # This is how one would use the QueryResult object