Fix for pow(double, double)

+ [python] check bounds for candidate set

2 files changed, 180 insertions, 128 deletions

diff --git a/python/src/_cdec.cpp b/python/src/_cdec.cpp
index bc522b32..948d99b6 100644
--- a/python/src/_cdec.cpp
+++ b/python/src/_cdec.cpp
@@ -1,4 +1,4 @@
-/* Generated by Cython 0.16 on Mon Jul  2 17:01:11 2012 */
+/* Generated by Cython 0.16 on Thu Jul  5 13:43:06 2012 */
 
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
@@ -421,7 +421,7 @@ struct __pyx_opt_args_5_cdec_as_str {
   PyObject *error_msg;
 };
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":109
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":111
  *         return CandidateSet(self)
  * 
  * cdef class Scorer:             # <<<<<<<<<<<<<<
@@ -534,7 +534,7 @@ struct __pyx_obj_5_cdec_Decoder {
 };
 
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":90
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":92
  *         self.cs.AddKBestCandidates(hypergraph.hg[0], k, self.scorer.get())
  * 
  * cdef class SegmentEvaluator:             # <<<<<<<<<<<<<<
@@ -686,7 +686,7 @@ struct __pyx_obj_5_cdec___pyx_scope_struct_6___iter__ {
 };
 
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":82
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":84
  *         return candidate
  * 
  *     def __iter__(self):             # <<<<<<<<<<<<<<
@@ -1088,7 +1088,7 @@ static PyObject *__pyx_pf_5_cdec_15SufficientStats_9__add__(struct __pyx_obj_5_c
 static int __pyx_pf_5_cdec_12CandidateSet___cinit__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, struct __pyx_obj_5_cdec_SegmentEvaluator *__pyx_v_evaluator); /* proto */
 static void __pyx_pf_5_cdec_12CandidateSet_2__dealloc__(CYTHON_UNUSED struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self); /* proto */
 static Py_ssize_t __pyx_pf_5_cdec_12CandidateSet_4__len__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self); /* proto */
-static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, unsigned int __pyx_v_k); /* proto */
+static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, int __pyx_v_k); /* proto */
 static PyObject *__pyx_pf_5_cdec_12CandidateSet_8__iter__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self); /* proto */
 static PyObject *__pyx_pf_5_cdec_12CandidateSet_11add_kbest(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, struct __pyx_obj_5_cdec_Hypergraph *__pyx_v_hypergraph, unsigned int __pyx_v_k); /* proto */
 static void __pyx_pf_5_cdec_16SegmentEvaluator___dealloc__(CYTHON_UNUSED struct __pyx_obj_5_cdec_SegmentEvaluator *__pyx_v_self); /* proto */
@@ -1112,7 +1112,8 @@ static char __pyx_k_11[] = "cannot reweight hypergraph with %s";
 static char __pyx_k_13[] = "Cannot create lattice from %s";
 static char __pyx_k_14[] = "lattice index out of range";
 static char __pyx_k_19[] = "Cannot convert type %s to str";
-static char __pyx_k_23[] = "Cannot translate input type %s";
+static char __pyx_k_21[] = "candidate set index out of range";
+static char __pyx_k_25[] = "Cannot translate input type %s";
 static char __pyx_k__k[] = "k";
 static char __pyx_k__TER[] = "TER";
 static char __pyx_k__dot[] = "dot";
@@ -1158,7 +1159,8 @@ static PyObject *__pyx_kp_s_13;
 static PyObject *__pyx_kp_s_14;
 static PyObject *__pyx_kp_s_19;
 static PyObject *__pyx_kp_s_2;
-static PyObject *__pyx_kp_s_23;
+static PyObject *__pyx_kp_s_21;
+static PyObject *__pyx_kp_s_25;
 static PyObject *__pyx_n_s__BLEU;
 static PyObject *__pyx_n_s__Exception;
 static PyObject *__pyx_n_s__IBM_BLEU;
@@ -1212,10 +1214,11 @@ static PyObject *__pyx_k_tuple_16;
 static PyObject *__pyx_k_tuple_17;
 static PyObject *__pyx_k_tuple_18;
 static PyObject *__pyx_k_tuple_20;
-static PyObject *__pyx_k_tuple_21;
 static PyObject *__pyx_k_tuple_22;
+static PyObject *__pyx_k_tuple_23;
 static PyObject *__pyx_k_tuple_24;
-static PyObject *__pyx_k_tuple_25;
+static PyObject *__pyx_k_tuple_26;
+static PyObject *__pyx_k_tuple_27;
 
 /* Python wrapper */
 static Py_ssize_t __pyx_pw_5_cdec_11DenseVector_1__len__(PyObject *__pyx_v_self); /*proto*/
@@ -6958,7 +6961,7 @@ static Py_ssize_t __pyx_pf_5_cdec_12CandidateSet_4__len__(struct __pyx_obj_5_cde
  *     def __len__(self):
  *         return self.cs.size()             # <<<<<<<<<<<<<<
  * 
- *     def __getitem__(self, unsigned k):
+ *     def __getitem__(self,int k):
  */
   __pyx_r = __pyx_v_self->cs->size();
   goto __pyx_L0;
@@ -6972,12 +6975,12 @@ static Py_ssize_t __pyx_pf_5_cdec_12CandidateSet_4__len__(struct __pyx_obj_5_cde
 /* Python wrapper */
 static PyObject *__pyx_pw_5_cdec_12CandidateSet_7__getitem__(PyObject *__pyx_v_self, PyObject *__pyx_arg_k); /*proto*/
 static PyObject *__pyx_pw_5_cdec_12CandidateSet_7__getitem__(PyObject *__pyx_v_self, PyObject *__pyx_arg_k) {
-  unsigned int __pyx_v_k;
+  int __pyx_v_k;
   PyObject *__pyx_r = 0;
   __Pyx_RefNannyDeclarations
   __Pyx_RefNannySetupContext("__getitem__ (wrapper)", 0);
   assert(__pyx_arg_k); {
-    __pyx_v_k = __Pyx_PyInt_AsUnsignedInt(__pyx_arg_k); if (unlikely((__pyx_v_k == (unsigned int)-1) && PyErr_Occurred())) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 76; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+    __pyx_v_k = __Pyx_PyInt_AsInt(__pyx_arg_k); if (unlikely((__pyx_v_k == (int)-1) && PyErr_Occurred())) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 76; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
   }
   goto __pyx_L4_argument_unpacking_done;
   __pyx_L3_error:;
@@ -6985,7 +6988,7 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_7__getitem__(PyObject *__pyx_v_s
   __Pyx_RefNannyFinishContext();
   return NULL;
   __pyx_L4_argument_unpacking_done:;
-  __pyx_r = __pyx_pf_5_cdec_12CandidateSet_6__getitem__(((struct __pyx_obj_5_cdec_CandidateSet *)__pyx_v_self), ((unsigned int)__pyx_v_k));
+  __pyx_r = __pyx_pf_5_cdec_12CandidateSet_6__getitem__(((struct __pyx_obj_5_cdec_CandidateSet *)__pyx_v_self), ((int)__pyx_v_k));
   __Pyx_RefNannyFinishContext();
   return __pyx_r;
 }
@@ -6993,16 +6996,18 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_7__getitem__(PyObject *__pyx_v_s
 /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":76
  *         return self.cs.size()
  * 
- *     def __getitem__(self, unsigned k):             # <<<<<<<<<<<<<<
- *         cdef Candidate candidate = Candidate()
- *         candidate.candidate = &self.cs[0][k]
+ *     def __getitem__(self,int k):             # <<<<<<<<<<<<<<
+ *         if not 0 <= k < self.cs.size():
+ *             raise IndexError('candidate set index out of range')
  */
 
-static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, unsigned int __pyx_v_k) {
+static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_cdec_CandidateSet *__pyx_v_self, int __pyx_v_k) {
   struct __pyx_obj_5_cdec_Candidate *__pyx_v_candidate = 0;
   PyObject *__pyx_r = NULL;
   __Pyx_RefNannyDeclarations
-  PyObject *__pyx_t_1 = NULL;
+  int __pyx_t_1;
+  int __pyx_t_2;
+  PyObject *__pyx_t_3 = NULL;
   int __pyx_lineno = 0;
   const char *__pyx_filename = NULL;
   int __pyx_clineno = 0;
@@ -7010,18 +7015,48 @@ static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_
 
   /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":77
  * 
- *     def __getitem__(self, unsigned k):
+ *     def __getitem__(self,int k):
+ *         if not 0 <= k < self.cs.size():             # <<<<<<<<<<<<<<
+ *             raise IndexError('candidate set index out of range')
+ *         cdef Candidate candidate = Candidate()
+ */
+  __pyx_t_1 = (0 <= __pyx_v_k);
+  if (__pyx_t_1) {
+    __pyx_t_1 = (__pyx_v_k < __pyx_v_self->cs->size());
+  }
+  __pyx_t_2 = (!__pyx_t_1);
+  if (__pyx_t_2) {
+
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":78
+ *     def __getitem__(self,int k):
+ *         if not 0 <= k < self.cs.size():
+ *             raise IndexError('candidate set index out of range')             # <<<<<<<<<<<<<<
+ *         cdef Candidate candidate = Candidate()
+ *         candidate.candidate = &self.cs[0][k]
+ */
+    __pyx_t_3 = PyObject_Call(__pyx_builtin_IndexError, ((PyObject *)__pyx_k_tuple_22), NULL); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 78; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __Pyx_GOTREF(__pyx_t_3);
+    __Pyx_Raise(__pyx_t_3, 0, 0, 0);
+    __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
+    {__pyx_filename = __pyx_f[4]; __pyx_lineno = 78; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    goto __pyx_L3;
+  }
+  __pyx_L3:;
+
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":79
+ *         if not 0 <= k < self.cs.size():
+ *             raise IndexError('candidate set index out of range')
  *         cdef Candidate candidate = Candidate()             # <<<<<<<<<<<<<<
  *         candidate.candidate = &self.cs[0][k]
  *         candidate.score = self.metric.ComputeScore(self.cs[0][k].eval_feats)
  */
-  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Candidate)), ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 77; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-  __Pyx_GOTREF(__pyx_t_1);
-  __pyx_v_candidate = ((struct __pyx_obj_5_cdec_Candidate *)__pyx_t_1);
-  __pyx_t_1 = 0;
+  __pyx_t_3 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Candidate)), ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 79; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_t_3);
+  __pyx_v_candidate = ((struct __pyx_obj_5_cdec_Candidate *)__pyx_t_3);
+  __pyx_t_3 = 0;
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":78
- *     def __getitem__(self, unsigned k):
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":80
+ *             raise IndexError('candidate set index out of range')
  *         cdef Candidate candidate = Candidate()
  *         candidate.candidate = &self.cs[0][k]             # <<<<<<<<<<<<<<
  *         candidate.score = self.metric.ComputeScore(self.cs[0][k].eval_feats)
@@ -7029,7 +7064,7 @@ static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_
  */
   __pyx_v_candidate->candidate = (&((__pyx_v_self->cs[0])[__pyx_v_k]));
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":79
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":81
  *         cdef Candidate candidate = Candidate()
  *         candidate.candidate = &self.cs[0][k]
  *         candidate.score = self.metric.ComputeScore(self.cs[0][k].eval_feats)             # <<<<<<<<<<<<<<
@@ -7038,7 +7073,7 @@ static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_
  */
   __pyx_v_candidate->score = __pyx_v_self->metric->ComputeScore(((__pyx_v_self->cs[0])[__pyx_v_k]).eval_feats);
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":80
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":82
  *         candidate.candidate = &self.cs[0][k]
  *         candidate.score = self.metric.ComputeScore(self.cs[0][k].eval_feats)
  *         return candidate             # <<<<<<<<<<<<<<
@@ -7053,7 +7088,7 @@ static PyObject *__pyx_pf_5_cdec_12CandidateSet_6__getitem__(struct __pyx_obj_5_
   __pyx_r = Py_None; __Pyx_INCREF(Py_None);
   goto __pyx_L0;
   __pyx_L1_error:;
-  __Pyx_XDECREF(__pyx_t_1);
+  __Pyx_XDECREF(__pyx_t_3);
   __Pyx_AddTraceback("_cdec.CandidateSet.__getitem__", __pyx_clineno, __pyx_lineno, __pyx_filename);
   __pyx_r = NULL;
   __pyx_L0:;
@@ -7075,7 +7110,7 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_9__iter__(PyObject *__pyx_v_self
   return __pyx_r;
 }
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":82
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":84
  *         return candidate
  * 
  *     def __iter__(self):             # <<<<<<<<<<<<<<
@@ -7101,7 +7136,7 @@ static PyObject *__pyx_pf_5_cdec_12CandidateSet_8__iter__(struct __pyx_obj_5_cde
   __Pyx_INCREF((PyObject *)__pyx_cur_scope->__pyx_v_self);
   __Pyx_GIVEREF((PyObject *)__pyx_cur_scope->__pyx_v_self);
   {
-    __pyx_GeneratorObject *gen = __Pyx_Generator_New((__pyx_generator_body_t) __pyx_gb_5_cdec_12CandidateSet_10generator8, (PyObject *) __pyx_cur_scope); if (unlikely(!gen)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 82; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_GeneratorObject *gen = __Pyx_Generator_New((__pyx_generator_body_t) __pyx_gb_5_cdec_12CandidateSet_10generator8, (PyObject *) __pyx_cur_scope); if (unlikely(!gen)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 84; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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     __Pyx_RefNannyFinishContext();
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@@ -7136,27 +7171,27 @@ static PyObject *__pyx_gb_5_cdec_12CandidateSet_10generator8(__pyx_GeneratorObje
     return NULL;
   }
   __pyx_L3_first_run:;
-  if (unlikely(!__pyx_sent_value)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 82; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (unlikely(!__pyx_sent_value)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 84; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":84
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":86
  *     def __iter__(self):
  *         cdef unsigned i
  *         for i in range(len(self)):             # <<<<<<<<<<<<<<
  *             yield self[i]
  * 
  */
-  __pyx_t_1 = PyObject_Length(((PyObject *)__pyx_cur_scope->__pyx_v_self)); if (unlikely(__pyx_t_1 == -1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 84; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = PyObject_Length(((PyObject *)__pyx_cur_scope->__pyx_v_self)); if (unlikely(__pyx_t_1 == -1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 86; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   for (__pyx_t_2 = 0; __pyx_t_2 < __pyx_t_1; __pyx_t_2+=1) {
     __pyx_cur_scope->__pyx_v_i = __pyx_t_2;
 
-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":85
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":87
  *         cdef unsigned i
  *         for i in range(len(self)):
  *             yield self[i]             # <<<<<<<<<<<<<<
  * 
  *     def add_kbest(self, Hypergraph hypergraph, unsigned k):
  */
-    __pyx_t_3 = __Pyx_GetItemInt(((PyObject *)__pyx_cur_scope->__pyx_v_self), __pyx_cur_scope->__pyx_v_i, sizeof(unsigned int)+1, PyLong_FromUnsignedLong); if (!__pyx_t_3) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 85; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_3 = __Pyx_GetItemInt(((PyObject *)__pyx_cur_scope->__pyx_v_self), __pyx_cur_scope->__pyx_v_i, sizeof(unsigned int)+1, PyLong_FromUnsignedLong); if (!__pyx_t_3) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_3);
     __pyx_r = __pyx_t_3;
     __pyx_t_3 = 0;
@@ -7170,7 +7205,7 @@ static PyObject *__pyx_gb_5_cdec_12CandidateSet_10generator8(__pyx_GeneratorObje
     __pyx_L6_resume_from_yield:;
     __pyx_t_1 = __pyx_cur_scope->__pyx_t_0;
     __pyx_t_2 = __pyx_cur_scope->__pyx_t_1;
-    if (unlikely(!__pyx_sent_value)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 85; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    if (unlikely(!__pyx_sent_value)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   }
   PyErr_SetNone(PyExc_StopIteration);
   goto __pyx_L0;
@@ -7214,11 +7249,11 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_12add_kbest(PyObject *__pyx_v_se
         values[1] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__k);
         if (likely(values[1])) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("add_kbest", 1, 2, 2, 1); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("add_kbest", 1, 2, 2, 1); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 89; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
       }
       if (unlikely(kw_args > 0)) {
-        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "add_kbest") < 0)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "add_kbest") < 0)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 89; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
       }
     } else if (PyTuple_GET_SIZE(__pyx_args) != 2) {
       goto __pyx_L5_argtuple_error;
@@ -7227,17 +7262,17 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_12add_kbest(PyObject *__pyx_v_se
       values[1] = PyTuple_GET_ITEM(__pyx_args, 1);
     }
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-    __pyx_v_k = __Pyx_PyInt_AsUnsignedInt(values[1]); if (unlikely((__pyx_v_k == (unsigned int)-1) && PyErr_Occurred())) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+    __pyx_v_k = __Pyx_PyInt_AsUnsignedInt(values[1]); if (unlikely((__pyx_v_k == (unsigned int)-1) && PyErr_Occurred())) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 89; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
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   goto __pyx_L4_argument_unpacking_done;
   __pyx_L5_argtuple_error:;
-  __Pyx_RaiseArgtupleInvalid("add_kbest", 1, 2, 2, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 87; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+  __Pyx_RaiseArgtupleInvalid("add_kbest", 1, 2, 2, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 89; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
   __pyx_L3_error:;
   __Pyx_AddTraceback("_cdec.CandidateSet.add_kbest", __pyx_clineno, __pyx_lineno, __pyx_filename);
   __Pyx_RefNannyFinishContext();
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   __pyx_L4_argument_unpacking_done:;
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+  if (unlikely(!__Pyx_ArgTypeTest(((PyObject *)__pyx_v_hypergraph), __pyx_ptype_5_cdec_Hypergraph, 1, "hypergraph", 0))) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 89; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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@@ -7247,7 +7282,7 @@ static PyObject *__pyx_pw_5_cdec_12CandidateSet_12add_kbest(PyObject *__pyx_v_se
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 }
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":87
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":89
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":88
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":90
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  *     def add_kbest(self, Hypergraph hypergraph, unsigned k):
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-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":94
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":96
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":95
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":97
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  *     def __dealloc__(self):
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@@ -7319,7 +7354,7 @@ static PyObject *__pyx_pw_5_cdec_16SegmentEvaluator_3evaluate(PyObject *__pyx_v_
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-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":97
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":99
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":99
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-  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_SufficientStats)), ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 99; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_SufficientStats)), ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 101; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":100
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":102
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":101
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":103
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":102
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":104
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+  __pyx_t_2 = PyObject_Call(__pyx_t_1, ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_2)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 104; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":103
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":104
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":106
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-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":106
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":108
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":107
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+  __pyx_t_1 = PyTuple_New(1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 109; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  __pyx_t_2 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_CandidateSet)), ((PyObject *)__pyx_t_1), NULL); if (unlikely(!__pyx_t_2)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 107; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_2 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_CandidateSet)), ((PyObject *)__pyx_t_1), NULL); if (unlikely(!__pyx_t_2)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 109; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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+  __Pyx_RaiseArgtupleInvalid("__cinit__", 1, 1, 1, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 114; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
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-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":112
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":114
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":113
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":116
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+  __Pyx_RaiseArgtupleInvalid("__call__", 1, 1, 1, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[4]; __pyx_lineno = 120; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
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-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":118
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":119
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":120
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-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":121
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":122
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":125
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     __pyx_t_7 = 0;
 
-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":126
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":128
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@@ -7772,22 +7807,22 @@ static PyObject *__pyx_pf_5_cdec_6Scorer_4__call__(struct __pyx_obj_5_cdec_Score
  */
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-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":127
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":129
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-    __pyx_t_7 = PyObject_GetAttr(__pyx_v_ref, __pyx_n_s__strip); if (unlikely(!__pyx_t_7)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 127; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_7 = PyObject_GetAttr(__pyx_v_ref, __pyx_n_s__strip); if (unlikely(!__pyx_t_7)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 129; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-    __pyx_t_8 = PyObject_Call(__pyx_t_7, ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_8)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 127; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_8 = PyObject_Call(__pyx_t_7, ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_8)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 129; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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     __Pyx_DECREF(__pyx_t_8); __pyx_t_8 = 0;
 
-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":128
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":130
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  *             refsv.push_back(refv[0])             # <<<<<<<<<<<<<<
@@ -7796,7 +7831,7 @@ static PyObject *__pyx_pf_5_cdec_6Scorer_4__call__(struct __pyx_obj_5_cdec_Score
  */
     __pyx_v_refsv->push_back((__pyx_v_refv[0]));
 
-    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":129
+    /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":131
  *             ConvertSentence(string(as_str(ref.strip())), refv)
  *             refsv.push_back(refv[0])
  *             del refv             # <<<<<<<<<<<<<<
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-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":131
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":133
  *             del refv
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+  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_SegmentEvaluator)), ((PyObject *)__pyx_empty_tuple), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 133; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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   __pyx_t_1 = 0;
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":132
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":134
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  */
   __pyx_v_evaluator->metric = __pyx_v_metric;
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":133
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":135
  *         cdef SegmentEvaluator evaluator = SegmentEvaluator()
  *         evaluator.metric = metric
  *         evaluator.scorer = new shared_ptr[mteval.SegmentEvaluator](metric.CreateSegmentEvaluator(refsv[0]))             # <<<<<<<<<<<<<<
@@ -7837,7 +7872,7 @@ static PyObject *__pyx_pf_5_cdec_6Scorer_4__call__(struct __pyx_obj_5_cdec_Score
  */
   __pyx_v_evaluator->scorer = new boost::shared_ptr<SegmentEvaluator>(__pyx_v_metric->CreateSegmentEvaluator((__pyx_v_refsv[0])));
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":134
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":136
  *         evaluator.metric = metric
  *         evaluator.scorer = new shared_ptr[mteval.SegmentEvaluator](metric.CreateSegmentEvaluator(refsv[0]))
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@@ -7846,7 +7881,7 @@ static PyObject *__pyx_pf_5_cdec_6Scorer_4__call__(struct __pyx_obj_5_cdec_Score
  */
   delete __pyx_v_refsv;
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":135
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":137
  *         evaluator.scorer = new shared_ptr[mteval.SegmentEvaluator](metric.CreateSegmentEvaluator(refsv[0]))
  *         del refsv # in theory should not delete but store in SegmentEvaluator
  *         return evaluator             # <<<<<<<<<<<<<<
@@ -7886,7 +7921,7 @@ static PyObject *__pyx_pw_5_cdec_6Scorer_7__str__(PyObject *__pyx_v_self) {
   return __pyx_r;
 }
 
-/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":137
+/* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":139
  *         return evaluator
  * 
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   __Pyx_RefNannySetupContext("__str__", 0);
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":138
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":140
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  *     def __str__(self):
  *         return self.name.c_str()             # <<<<<<<<<<<<<<
@@ -7911,7 +7946,7 @@ static PyObject *__pyx_pf_5_cdec_6Scorer_6__str__(struct __pyx_obj_5_cdec_Scorer
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  */
   __Pyx_XDECREF(__pyx_r);
-  __pyx_t_1 = PyBytes_FromString(__pyx_v_self->name->c_str()); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 138; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = PyBytes_FromString(__pyx_v_self->name->c_str()); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 140; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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@@ -8375,7 +8410,7 @@ static PyObject *__pyx_pf_5_cdec_7Decoder_4read_weights(struct __pyx_obj_5_cdec_
     }
     /*finally:*/ {
       if (__pyx_t_3) {
-        __pyx_t_7 = PyObject_Call(__pyx_t_3, __pyx_k_tuple_21, NULL);
+        __pyx_t_7 = PyObject_Call(__pyx_t_3, __pyx_k_tuple_23, NULL);
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@@ -8522,7 +8557,7 @@ static PyObject *__pyx_pf_5_cdec_7Decoder_6translate(struct __pyx_obj_5_cdec_Dec
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+    __pyx_t_3 = PyObject_Call(__pyx_t_1, ((PyObject *)__pyx_k_tuple_24), NULL); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 38; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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@@ -8601,7 +8636,7 @@ static PyObject *__pyx_pf_5_cdec_7Decoder_6translate(struct __pyx_obj_5_cdec_Dec
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+    __pyx_t_3 = PyNumber_Remainder(((PyObject *)__pyx_kp_s_25), ((PyObject *)Py_TYPE(__pyx_v_sentence))); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 44; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  {&__pyx_kp_s_23, __pyx_k_23, sizeof(__pyx_k_23), 0, 0, 1, 0},
+  {&__pyx_kp_s_21, __pyx_k_21, sizeof(__pyx_k_21), 0, 0, 1, 0},
+  {&__pyx_kp_s_25, __pyx_k_25, sizeof(__pyx_k_25), 0, 0, 1, 0},
   {&__pyx_n_s__BLEU, __pyx_k__BLEU, sizeof(__pyx_k__BLEU), 0, 0, 1, 1},
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   __Pyx_GIVEREF(((PyObject *)__pyx_n_s__utf8));
   __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_20));
 
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":78
+ *     def __getitem__(self,int k):
+ *         if not 0 <= k < self.cs.size():
+ *             raise IndexError('candidate set index out of range')             # <<<<<<<<<<<<<<
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+ *         candidate.candidate = &self.cs[0][k]
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+  __pyx_k_tuple_22 = PyTuple_New(1); if (unlikely(!__pyx_k_tuple_22)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 78; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_k_tuple_22);
+  __Pyx_INCREF(((PyObject *)__pyx_kp_s_21));
+  PyTuple_SET_ITEM(__pyx_k_tuple_22, 0, ((PyObject *)__pyx_kp_s_21));
+  __Pyx_GIVEREF(((PyObject *)__pyx_kp_s_21));
+  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_22));
+
   /* "_cdec.pyx":31
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  *     def read_weights(self, cfg):
@@ -12822,18 +12872,18 @@ static int __Pyx_InitCachedConstants(void) {
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-  __pyx_k_tuple_21 = PyTuple_New(3); if (unlikely(!__pyx_k_tuple_21)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 31; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-  __Pyx_GOTREF(__pyx_k_tuple_21);
+  __pyx_k_tuple_23 = PyTuple_New(3); if (unlikely(!__pyx_k_tuple_23)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 31; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_k_tuple_23);
   __Pyx_INCREF(Py_None);
-  PyTuple_SET_ITEM(__pyx_k_tuple_21, 0, Py_None);
+  PyTuple_SET_ITEM(__pyx_k_tuple_23, 0, Py_None);
   __Pyx_GIVEREF(Py_None);
   __Pyx_INCREF(Py_None);
-  PyTuple_SET_ITEM(__pyx_k_tuple_21, 1, Py_None);
+  PyTuple_SET_ITEM(__pyx_k_tuple_23, 1, Py_None);
   __Pyx_GIVEREF(Py_None);
   __Pyx_INCREF(Py_None);
-  PyTuple_SET_ITEM(__pyx_k_tuple_21, 2, Py_None);
+  PyTuple_SET_ITEM(__pyx_k_tuple_23, 2, Py_None);
   __Pyx_GIVEREF(Py_None);
-  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_21));
+  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_23));
 
   /* "_cdec.pyx":38
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-  __Pyx_GOTREF(__pyx_k_tuple_22);
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   __Pyx_INCREF(((PyObject *)__pyx_n_s__utf8));
-  PyTuple_SET_ITEM(__pyx_k_tuple_22, 0, ((PyObject *)__pyx_n_s__utf8));
+  PyTuple_SET_ITEM(__pyx_k_tuple_24, 0, ((PyObject *)__pyx_n_s__utf8));
   __Pyx_GIVEREF(((PyObject *)__pyx_n_s__utf8));
-  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_22));
+  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_24));
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":140
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  * 
  * BLEU = Scorer('IBM_BLEU')             # <<<<<<<<<<<<<<
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-  __pyx_k_tuple_24 = PyTuple_New(1); if (unlikely(!__pyx_k_tuple_24)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 140; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-  __Pyx_GOTREF(__pyx_k_tuple_24);
+  __pyx_k_tuple_26 = PyTuple_New(1); if (unlikely(!__pyx_k_tuple_26)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 142; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_k_tuple_26);
   __Pyx_INCREF(((PyObject *)__pyx_n_s__IBM_BLEU));
-  PyTuple_SET_ITEM(__pyx_k_tuple_24, 0, ((PyObject *)__pyx_n_s__IBM_BLEU));
+  PyTuple_SET_ITEM(__pyx_k_tuple_26, 0, ((PyObject *)__pyx_n_s__IBM_BLEU));
   __Pyx_GIVEREF(((PyObject *)__pyx_n_s__IBM_BLEU));
-  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_24));
+  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_26));
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":141
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-  __Pyx_GOTREF(__pyx_k_tuple_25);
+  __pyx_k_tuple_27 = PyTuple_New(1); if (unlikely(!__pyx_k_tuple_27)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 143; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_25));
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+  if (PyType_Ready(&__pyx_type_5_cdec_SegmentEvaluator) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 92; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (__Pyx_SetAttrString(__pyx_m, "SegmentEvaluator", (PyObject *)&__pyx_type_5_cdec_SegmentEvaluator) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 92; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
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-  if (__Pyx_SetAttrString(__pyx_m, "Scorer", (PyObject *)&__pyx_type_5_cdec_Scorer) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 109; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyType_Ready(&__pyx_type_5_cdec_Scorer) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 111; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (__Pyx_SetAttrString(__pyx_m, "Scorer", (PyObject *)&__pyx_type_5_cdec_Scorer) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 111; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __pyx_ptype_5_cdec_Scorer = &__pyx_type_5_cdec_Scorer;
   if (PyType_Ready(&__pyx_type_5_cdec_Decoder) < 0) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 15; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   if (__Pyx_SetAttrString(__pyx_m, "Decoder", (PyObject *)&__pyx_type_5_cdec_Decoder) < 0) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 15; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
@@ -13002,32 +13052,32 @@ PyMODINIT_FUNC PyInit__cdec(void)
   __pyx_ptype_5_cdec___pyx_scope_struct_6___iter__ = &__pyx_type_5_cdec___pyx_scope_struct_6___iter__;
   if (PyType_Ready(&__pyx_type_5_cdec___pyx_scope_struct_7___iter__) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 45; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __pyx_ptype_5_cdec___pyx_scope_struct_7___iter__ = &__pyx_type_5_cdec___pyx_scope_struct_7___iter__;
-  if (PyType_Ready(&__pyx_type_5_cdec___pyx_scope_struct_8___iter__) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 82; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyType_Ready(&__pyx_type_5_cdec___pyx_scope_struct_8___iter__) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 84; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __pyx_ptype_5_cdec___pyx_scope_struct_8___iter__ = &__pyx_type_5_cdec___pyx_scope_struct_8___iter__;
   /*--- Type import code ---*/
   /*--- Variable import code ---*/
   /*--- Function import code ---*/
   /*--- Execution code ---*/
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":140
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":142
  *         return self.name.c_str()
  * 
  * BLEU = Scorer('IBM_BLEU')             # <<<<<<<<<<<<<<
  * TER = Scorer('TER')
  */
-  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Scorer)), ((PyObject *)__pyx_k_tuple_24), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 140; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Scorer)), ((PyObject *)__pyx_k_tuple_26), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 142; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_1);
-  if (PyObject_SetAttr(__pyx_m, __pyx_n_s__BLEU, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 140; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyObject_SetAttr(__pyx_m, __pyx_n_s__BLEU, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 142; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
 
-  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":141
+  /* "/Users/vchahun/Sandbox/cdec/python/src/mteval.pxi":143
  * 
  * BLEU = Scorer('IBM_BLEU')
  * TER = Scorer('TER')             # <<<<<<<<<<<<<<
  */
-  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Scorer)), ((PyObject *)__pyx_k_tuple_25), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 141; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = PyObject_Call(((PyObject *)((PyObject*)__pyx_ptype_5_cdec_Scorer)), ((PyObject *)__pyx_k_tuple_27), NULL); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 143; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_1);
-  if (PyObject_SetAttr(__pyx_m, __pyx_n_s__TER, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 141; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyObject_SetAttr(__pyx_m, __pyx_n_s__TER, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[4]; __pyx_lineno = 143; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
 
   /* "_cdec.pyx":11
diff --git a/python/src/mteval.pxi b/python/src/mteval.pxi
index 9afb6fe1..67a29f6f 100644
--- a/python/src/mteval.pxi
+++ b/python/src/mteval.pxi
@@ -73,7 +73,9 @@ cdef class CandidateSet:
     def __len__(self):
         return self.cs.size()
 
-    def __getitem__(self, unsigned k):
+    def __getitem__(self,int k):
+        if not 0 <= k < self.cs.size():
+            raise IndexError('candidate set index out of range')
         cdef Candidate candidate = Candidate()
         candidate.candidate = &self.cs[0][k]
         candidate.score = self.metric.ComputeScore(self.cs[0][k].eval_feats)