Support clearning context

3 files changed, 189 insertions, 68 deletions

diff --git a/python/cdec/sa/_sa.c b/python/cdec/sa/_sa.c
index 0352a202..a9f7855e 100644
--- a/python/cdec/sa/_sa.c
+++ b/python/cdec/sa/_sa.c
@@ -1,4 +1,4 @@
-/* Generated by Cython 0.19.1 on Mon Sep 23 08:03:57 2013 */
+/* Generated by Cython 0.19.1 on Tue Sep 24 13:39:51 2013 */
 
 #define PY_SSIZE_T_CLEAN
 #ifndef CYTHON_USE_PYLONG_INTERNALS
@@ -2836,6 +2836,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_29fmt_rule(st
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_31online_ctx_lookup(struct __pyx_obj_4cdec_2sa_3_sa_HieroCachingRuleFactory *__pyx_v_self, PyObject *__pyx_v_f, PyObject *__pyx_v_e, PyObject *__pyx_v_ctx_name); /* proto */
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_13get_f_phrases_extract(PyObject *__pyx_self, PyObject *__pyx_v_f_i, PyObject *__pyx_v_f_j, PyObject *__pyx_v_lex_i, PyObject *__pyx_v_lex_j, PyObject *__pyx_v_wc, PyObject *__pyx_v_ntc, PyObject *__pyx_v_syms); /* proto */
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_33get_f_phrases(struct __pyx_obj_4cdec_2sa_3_sa_HieroCachingRuleFactory *__pyx_v_self, PyObject *__pyx_v_f_words); /* proto */
+static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_35drop_ctx(struct __pyx_obj_4cdec_2sa_3_sa_HieroCachingRuleFactory *__pyx_v_self, PyObject *__pyx_v_ctx_name); /* proto */
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__pyx_self, PyObject *__pyx_v_vec, PyObject *__pyx_v_i, PyObject *__pyx_v_j); /* proto */
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_18span_inc(CYTHON_UNUSED PyObject *__pyx_self, PyObject *__pyx_v_vec, PyObject *__pyx_v_i, PyObject *__pyx_v_j); /* proto */
 static PyObject *__pyx_pf_4cdec_2sa_3_sa_20span_dec(CYTHON_UNUSED PyObject *__pyx_self, PyObject *__pyx_v_vec, PyObject *__pyx_v_i, PyObject *__pyx_v_j); /* proto */
@@ -66237,7 +66238,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_33get_f_phras
  * 
  *         return phrases             # <<<<<<<<<<<<<<
  * 
- * # Spans are _inclusive_ on both ends [i, j]
+ *     # Drop online stats for a context
  */
   __Pyx_XDECREF(__pyx_r);
   __Pyx_INCREF(((PyObject *)__pyx_cur_scope->__pyx_v_phrases));
@@ -66262,6 +66263,117 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_33get_f_phras
 }
 
 /* Python wrapper */
+static PyObject *__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_36drop_ctx(PyObject *__pyx_v_self, PyObject *__pyx_args, PyObject *__pyx_kwds); /*proto*/
+static PyObject *__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_36drop_ctx(PyObject *__pyx_v_self, PyObject *__pyx_args, PyObject *__pyx_kwds) {
+  PyObject *__pyx_v_ctx_name = 0;
+  int __pyx_lineno = 0;
+  const char *__pyx_filename = NULL;
+  int __pyx_clineno = 0;
+  PyObject *__pyx_r = 0;
+  __Pyx_RefNannyDeclarations
+  __Pyx_RefNannySetupContext("drop_ctx (wrapper)", 0);
+  {
+    static PyObject **__pyx_pyargnames[] = {&__pyx_n_s__ctx_name,0};
+    PyObject* values[1] = {0};
+
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2186
+ * 
+ *     # Drop online stats for a context
+ *     def drop_ctx(self, ctx_name=None):             # <<<<<<<<<<<<<<
+ *         self.online_stats.pop(ctx_name, None)
+ * 
+ */
+    values[0] = ((PyObject *)Py_None);
+    if (unlikely(__pyx_kwds)) {
+      Py_ssize_t kw_args;
+      const Py_ssize_t pos_args = PyTuple_GET_SIZE(__pyx_args);
+      switch (pos_args) {
+        case  1: values[0] = PyTuple_GET_ITEM(__pyx_args, 0);
+        case  0: break;
+        default: goto __pyx_L5_argtuple_error;
+      }
+      kw_args = PyDict_Size(__pyx_kwds);
+      switch (pos_args) {
+        case  0:
+        if (kw_args > 0) {
+          PyObject* value = PyDict_GetItem(__pyx_kwds, __pyx_n_s__ctx_name);
+          if (value) { values[0] = value; kw_args--; }
+        }
+      }
+      if (unlikely(kw_args > 0)) {
+        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "drop_ctx") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+      }
+    } else {
+      switch (PyTuple_GET_SIZE(__pyx_args)) {
+        case  1: values[0] = PyTuple_GET_ITEM(__pyx_args, 0);
+        case  0: break;
+        default: goto __pyx_L5_argtuple_error;
+      }
+    }
+    __pyx_v_ctx_name = values[0];
+  }
+  goto __pyx_L4_argument_unpacking_done;
+  __pyx_L5_argtuple_error:;
+  __Pyx_RaiseArgtupleInvalid("drop_ctx", 0, 0, 1, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+  __pyx_L3_error:;
+  __Pyx_AddTraceback("cdec.sa._sa.HieroCachingRuleFactory.drop_ctx", __pyx_clineno, __pyx_lineno, __pyx_filename);
+  __Pyx_RefNannyFinishContext();
+  return NULL;
+  __pyx_L4_argument_unpacking_done:;
+  __pyx_r = __pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_35drop_ctx(((struct __pyx_obj_4cdec_2sa_3_sa_HieroCachingRuleFactory *)__pyx_v_self), __pyx_v_ctx_name);
+  __Pyx_RefNannyFinishContext();
+  return __pyx_r;
+}
+
+static PyObject *__pyx_pf_4cdec_2sa_3_sa_23HieroCachingRuleFactory_35drop_ctx(struct __pyx_obj_4cdec_2sa_3_sa_HieroCachingRuleFactory *__pyx_v_self, PyObject *__pyx_v_ctx_name) {
+  PyObject *__pyx_r = NULL;
+  __Pyx_RefNannyDeclarations
+  PyObject *__pyx_t_1 = NULL;
+  PyObject *__pyx_t_2 = NULL;
+  PyObject *__pyx_t_3 = NULL;
+  int __pyx_lineno = 0;
+  const char *__pyx_filename = NULL;
+  int __pyx_clineno = 0;
+  __Pyx_RefNannySetupContext("drop_ctx", 0);
+
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2187
+ *     # Drop online stats for a context
+ *     def drop_ctx(self, ctx_name=None):
+ *         self.online_stats.pop(ctx_name, None)             # <<<<<<<<<<<<<<
+ * 
+ * # Spans are _inclusive_ on both ends [i, j]
+ */
+  __pyx_t_1 = __Pyx_PyObject_GetAttrStr(__pyx_v_self->online_stats, __pyx_n_s__pop); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2187; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_t_1);
+  __pyx_t_2 = PyTuple_New(2); if (unlikely(!__pyx_t_2)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2187; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_t_2);
+  __Pyx_INCREF(__pyx_v_ctx_name);
+  PyTuple_SET_ITEM(__pyx_t_2, 0, __pyx_v_ctx_name);
+  __Pyx_GIVEREF(__pyx_v_ctx_name);
+  __Pyx_INCREF(Py_None);
+  PyTuple_SET_ITEM(__pyx_t_2, 1, Py_None);
+  __Pyx_GIVEREF(Py_None);
+  __pyx_t_3 = PyObject_Call(__pyx_t_1, ((PyObject *)__pyx_t_2), NULL); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2187; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __Pyx_GOTREF(__pyx_t_3);
+  __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
+  __Pyx_DECREF(((PyObject *)__pyx_t_2)); __pyx_t_2 = 0;
+  __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
+
+  __pyx_r = Py_None; __Pyx_INCREF(Py_None);
+  goto __pyx_L0;
+  __pyx_L1_error:;
+  __Pyx_XDECREF(__pyx_t_1);
+  __Pyx_XDECREF(__pyx_t_2);
+  __Pyx_XDECREF(__pyx_t_3);
+  __Pyx_AddTraceback("cdec.sa._sa.HieroCachingRuleFactory.drop_ctx", __pyx_clineno, __pyx_lineno, __pyx_filename);
+  __pyx_r = NULL;
+  __pyx_L0:;
+  __Pyx_XGIVEREF(__pyx_r);
+  __Pyx_RefNannyFinishContext();
+  return __pyx_r;
+}
+
+/* Python wrapper */
 static PyObject *__pyx_pw_4cdec_2sa_3_sa_17span_check(PyObject *__pyx_self, PyObject *__pyx_args, PyObject *__pyx_kwds); /*proto*/
 static PyMethodDef __pyx_mdef_4cdec_2sa_3_sa_17span_check = {__Pyx_NAMESTR("span_check"), (PyCFunction)__pyx_pw_4cdec_2sa_3_sa_17span_check, METH_VARARGS|METH_KEYWORDS, __Pyx_DOCSTR(0)};
 static PyObject *__pyx_pw_4cdec_2sa_3_sa_17span_check(PyObject *__pyx_self, PyObject *__pyx_args, PyObject *__pyx_kwds) {
@@ -66295,16 +66407,16 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_17span_check(PyObject *__pyx_self, PyOb
         case  1:
         if (likely((values[1] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__i)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
         case  2:
         if (likely((values[2] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__j)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
       }
       if (unlikely(kw_args > 0)) {
-        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_check") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_check") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
       }
     } else if (PyTuple_GET_SIZE(__pyx_args) != 3) {
       goto __pyx_L5_argtuple_error;
@@ -66319,7 +66431,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_17span_check(PyObject *__pyx_self, PyOb
   }
   goto __pyx_L4_argument_unpacking_done;
   __pyx_L5_argtuple_error:;
-  __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+  __Pyx_RaiseArgtupleInvalid("span_check", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
   __pyx_L3_error:;
   __Pyx_AddTraceback("cdec.sa._sa.span_check", __pyx_clineno, __pyx_lineno, __pyx_filename);
   __Pyx_RefNannyFinishContext();
@@ -66330,7 +66442,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_17span_check(PyObject *__pyx_self, PyOb
   return __pyx_r;
 }
 
-/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2186
+/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2190
  * 
  * # Spans are _inclusive_ on both ends [i, j]
  * def span_check(vec, i, j):             # <<<<<<<<<<<<<<
@@ -66349,7 +66461,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
   int __pyx_clineno = 0;
   __Pyx_RefNannySetupContext("span_check", 0);
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2187
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2191
  * # Spans are _inclusive_ on both ends [i, j]
  * def span_check(vec, i, j):
  *     k = i             # <<<<<<<<<<<<<<
@@ -66359,7 +66471,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
   __Pyx_INCREF(__pyx_v_i);
   __pyx_v_k = __pyx_v_i;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2188
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2192
  * def span_check(vec, i, j):
  *     k = i
  *     while k <= j:             # <<<<<<<<<<<<<<
@@ -66367,25 +66479,25 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
  *             return False
  */
   while (1) {
-    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2188; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2188; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2192; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2192; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
     if (!__pyx_t_2) break;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2189
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2193
  *     k = i
  *     while k <= j:
  *         if vec[k]:             # <<<<<<<<<<<<<<
  *             return False
  *         k += 1
  */
-    __pyx_t_1 = PyObject_GetItem(__pyx_v_vec, __pyx_v_k); if (!__pyx_t_1) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2189; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyObject_GetItem(__pyx_v_vec, __pyx_v_k); if (!__pyx_t_1) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2193; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_1);
-    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2189; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2193; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
     if (__pyx_t_2) {
 
-      /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2190
+      /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2194
  *     while k <= j:
  *         if vec[k]:
  *             return False             # <<<<<<<<<<<<<<
@@ -66393,7 +66505,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
  *     return True
  */
       __Pyx_XDECREF(__pyx_r);
-      __pyx_t_1 = __Pyx_PyBool_FromLong(0); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+      __pyx_t_1 = __Pyx_PyBool_FromLong(0); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
       __Pyx_GOTREF(__pyx_t_1);
       __pyx_r = __pyx_t_1;
       __pyx_t_1 = 0;
@@ -66402,21 +66514,21 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
     }
     __pyx_L5:;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2191
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2195
  *         if vec[k]:
  *             return False
  *         k += 1             # <<<<<<<<<<<<<<
  *     return True
  * 
  */
-    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2191; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2195; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_1);
     __Pyx_DECREF(__pyx_v_k);
     __pyx_v_k = __pyx_t_1;
     __pyx_t_1 = 0;
   }
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2192
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2196
  *             return False
  *         k += 1
  *     return True             # <<<<<<<<<<<<<<
@@ -66424,7 +66536,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_16span_check(CYTHON_UNUSED PyObject *__
  * def span_inc(vec, i, j):
  */
   __Pyx_XDECREF(__pyx_r);
-  __pyx_t_1 = __Pyx_PyBool_FromLong(1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2192; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_1 = __Pyx_PyBool_FromLong(1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2196; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_1);
   __pyx_r = __pyx_t_1;
   __pyx_t_1 = 0;
@@ -66477,16 +66589,16 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_19span_inc(PyObject *__pyx_self, PyObje
         case  1:
         if (likely((values[1] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__i)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
         case  2:
         if (likely((values[2] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__j)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
       }
       if (unlikely(kw_args > 0)) {
-        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_inc") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_inc") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
       }
     } else if (PyTuple_GET_SIZE(__pyx_args) != 3) {
       goto __pyx_L5_argtuple_error;
@@ -66501,7 +66613,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_19span_inc(PyObject *__pyx_self, PyObje
   }
   goto __pyx_L4_argument_unpacking_done;
   __pyx_L5_argtuple_error:;
-  __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+  __Pyx_RaiseArgtupleInvalid("span_inc", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
   __pyx_L3_error:;
   __Pyx_AddTraceback("cdec.sa._sa.span_inc", __pyx_clineno, __pyx_lineno, __pyx_filename);
   __Pyx_RefNannyFinishContext();
@@ -66512,7 +66624,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_19span_inc(PyObject *__pyx_self, PyObje
   return __pyx_r;
 }
 
-/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2194
+/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2198
  *     return True
  * 
  * def span_inc(vec, i, j):             # <<<<<<<<<<<<<<
@@ -66533,7 +66645,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_18span_inc(CYTHON_UNUSED PyObject *__py
   int __pyx_clineno = 0;
   __Pyx_RefNannySetupContext("span_inc", 0);
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2195
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2199
  * 
  * def span_inc(vec, i, j):
  *     k = i             # <<<<<<<<<<<<<<
@@ -66543,7 +66655,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_18span_inc(CYTHON_UNUSED PyObject *__py
   __Pyx_INCREF(__pyx_v_i);
   __pyx_v_k = __pyx_v_i;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2196
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2200
  * def span_inc(vec, i, j):
  *     k = i
  *     while k <= j:             # <<<<<<<<<<<<<<
@@ -66551,12 +66663,12 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_18span_inc(CYTHON_UNUSED PyObject *__py
  *         k += 1
  */
   while (1) {
-    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2196; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2196; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
     if (!__pyx_t_2) break;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2197
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2201
  *     k = i
  *     while k <= j:
  *         vec[k] += 1             # <<<<<<<<<<<<<<
@@ -66565,23 +66677,23 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_18span_inc(CYTHON_UNUSED PyObject *__py
  */
     __Pyx_INCREF(__pyx_v_k);
     __pyx_t_1 = __pyx_v_k;
-    __pyx_t_3 = PyObject_GetItem(__pyx_v_vec, __pyx_t_1); if (!__pyx_t_3) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2197; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_3 = PyObject_GetItem(__pyx_v_vec, __pyx_t_1); if (!__pyx_t_3) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2201; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_3);
-    __pyx_t_4 = PyNumber_InPlaceAdd(__pyx_t_3, __pyx_int_1); if (unlikely(!__pyx_t_4)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2197; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_4 = PyNumber_InPlaceAdd(__pyx_t_3, __pyx_int_1); if (unlikely(!__pyx_t_4)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2201; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_4);
     __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
-    if (PyObject_SetItem(__pyx_v_vec, __pyx_t_1, __pyx_t_4) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2197; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    if (PyObject_SetItem(__pyx_v_vec, __pyx_t_1, __pyx_t_4) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2201; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_4); __pyx_t_4 = 0;
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2198
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2202
  *     while k <= j:
  *         vec[k] += 1
  *         k += 1             # <<<<<<<<<<<<<<
  * 
  * def span_dec(vec, i, j):
  */
-    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2202; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_1);
     __Pyx_DECREF(__pyx_v_k);
     __pyx_v_k = __pyx_t_1;
@@ -66637,16 +66749,16 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_21span_dec(PyObject *__pyx_self, PyObje
         case  1:
         if (likely((values[1] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__i)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, 1); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
         case  2:
         if (likely((values[2] = PyDict_GetItem(__pyx_kwds, __pyx_n_s__j)) != 0)) kw_args--;
         else {
-          __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+          __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, 2); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
         }
       }
       if (unlikely(kw_args > 0)) {
-        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_dec") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+        if (unlikely(__Pyx_ParseOptionalKeywords(__pyx_kwds, __pyx_pyargnames, 0, values, pos_args, "span_dec") < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
       }
     } else if (PyTuple_GET_SIZE(__pyx_args) != 3) {
       goto __pyx_L5_argtuple_error;
@@ -66661,7 +66773,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_21span_dec(PyObject *__pyx_self, PyObje
   }
   goto __pyx_L4_argument_unpacking_done;
   __pyx_L5_argtuple_error:;
-  __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
+  __Pyx_RaiseArgtupleInvalid("span_dec", 1, 3, 3, PyTuple_GET_SIZE(__pyx_args)); {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L3_error;}
   __pyx_L3_error:;
   __Pyx_AddTraceback("cdec.sa._sa.span_dec", __pyx_clineno, __pyx_lineno, __pyx_filename);
   __Pyx_RefNannyFinishContext();
@@ -66672,7 +66784,7 @@ static PyObject *__pyx_pw_4cdec_2sa_3_sa_21span_dec(PyObject *__pyx_self, PyObje
   return __pyx_r;
 }
 
-/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2200
+/* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2204
  *         k += 1
  * 
  * def span_dec(vec, i, j):             # <<<<<<<<<<<<<<
@@ -66693,7 +66805,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_20span_dec(CYTHON_UNUSED PyObject *__py
   int __pyx_clineno = 0;
   __Pyx_RefNannySetupContext("span_dec", 0);
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2201
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2205
  * 
  * def span_dec(vec, i, j):
  *     k = i             # <<<<<<<<<<<<<<
@@ -66703,7 +66815,7 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_20span_dec(CYTHON_UNUSED PyObject *__py
   __Pyx_INCREF(__pyx_v_i);
   __pyx_v_k = __pyx_v_i;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2202
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2206
  * def span_dec(vec, i, j):
  *     k = i
  *     while k <= j:             # <<<<<<<<<<<<<<
@@ -66711,12 +66823,12 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_20span_dec(CYTHON_UNUSED PyObject *__py
  *         k += 1
  */
   while (1) {
-    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2202; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
-    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2202; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyObject_RichCompare(__pyx_v_k, __pyx_v_j, Py_LE); __Pyx_XGOTREF(__pyx_t_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2206; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_2 = __Pyx_PyObject_IsTrue(__pyx_t_1); if (unlikely(__pyx_t_2 < 0)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2206; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
     if (!__pyx_t_2) break;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2203
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2207
  *     k = i
  *     while k <= j:
  *         vec[k] -= 1             # <<<<<<<<<<<<<<
@@ -66724,21 +66836,21 @@ static PyObject *__pyx_pf_4cdec_2sa_3_sa_20span_dec(CYTHON_UNUSED PyObject *__py
  */
     __Pyx_INCREF(__pyx_v_k);
     __pyx_t_1 = __pyx_v_k;
-    __pyx_t_3 = PyObject_GetItem(__pyx_v_vec, __pyx_t_1); if (!__pyx_t_3) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2203; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_3 = PyObject_GetItem(__pyx_v_vec, __pyx_t_1); if (!__pyx_t_3) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2207; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_3);
-    __pyx_t_4 = PyNumber_InPlaceSubtract(__pyx_t_3, __pyx_int_1); if (unlikely(!__pyx_t_4)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2203; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_4 = PyNumber_InPlaceSubtract(__pyx_t_3, __pyx_int_1); if (unlikely(!__pyx_t_4)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2207; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_4);
     __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
-    if (PyObject_SetItem(__pyx_v_vec, __pyx_t_1, __pyx_t_4) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2203; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    if (PyObject_SetItem(__pyx_v_vec, __pyx_t_1, __pyx_t_4) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2207; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_DECREF(__pyx_t_4); __pyx_t_4 = 0;
     __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
 
-    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2204
+    /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2208
  *     while k <= j:
  *         vec[k] -= 1
  *         k += 1             # <<<<<<<<<<<<<<
  */
-    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+    __pyx_t_1 = PyNumber_InPlaceAdd(__pyx_v_k, __pyx_int_1); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2208; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
     __Pyx_GOTREF(__pyx_t_1);
     __Pyx_DECREF(__pyx_v_k);
     __pyx_v_k = __pyx_t_1;
@@ -74336,6 +74448,7 @@ static PyMethodDef __pyx_methods_4cdec_2sa_3_sa_HieroCachingRuleFactory[] = {
   {__Pyx_NAMESTR("fmt_rule"), (PyCFunction)__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_30fmt_rule, METH_VARARGS|METH_KEYWORDS, __Pyx_DOCSTR(0)},
   {__Pyx_NAMESTR("online_ctx_lookup"), (PyCFunction)__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_32online_ctx_lookup, METH_VARARGS|METH_KEYWORDS, __Pyx_DOCSTR(0)},
   {__Pyx_NAMESTR("get_f_phrases"), (PyCFunction)__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_34get_f_phrases, METH_O, __Pyx_DOCSTR(0)},
+  {__Pyx_NAMESTR("drop_ctx"), (PyCFunction)__pyx_pw_4cdec_2sa_3_sa_23HieroCachingRuleFactory_36drop_ctx, METH_VARARGS|METH_KEYWORDS, __Pyx_DOCSTR(0)},
   {0, 0, 0, 0}
 };
 
@@ -76391,41 +76504,41 @@ static int __Pyx_InitCachedConstants(void) {
   __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_174));
   __pyx_k_codeobj_175 = (PyObject*)__Pyx_PyCode_New(1, 0, 3, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_174, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_165, __pyx_n_s__decode_words, 124, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_175)) {__pyx_filename = __pyx_f[10]; __pyx_lineno = 124; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2186
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2190
  * 
  * # Spans are _inclusive_ on both ends [i, j]
  * def span_check(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_k_tuple_177 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_177)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_tuple_177 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_177)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_k_tuple_177);
   __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_177));
-  __pyx_k_codeobj_178 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_177, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_check, 2186, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_178)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_codeobj_178 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_177, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_check, 2190, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_178)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2194
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2198
  *     return True
  * 
  * def span_inc(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_k_tuple_179 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_179)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_tuple_179 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_179)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_k_tuple_179);
   __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_179));
-  __pyx_k_codeobj_180 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_179, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_inc, 2194, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_180)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_codeobj_180 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_179, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_inc, 2198, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_180)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2200
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2204
  *         k += 1
  * 
  * def span_dec(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_k_tuple_181 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_181)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_tuple_181 = PyTuple_Pack(4, ((PyObject *)__pyx_n_s__vec), ((PyObject *)__pyx_n_s__i), ((PyObject *)__pyx_n_s__j), ((PyObject *)__pyx_n_s__k)); if (unlikely(!__pyx_k_tuple_181)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_k_tuple_181);
   __Pyx_GIVEREF(((PyObject *)__pyx_k_tuple_181));
-  __pyx_k_codeobj_182 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_181, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_dec, 2200, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_182)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_k_codeobj_182 = (PyObject*)__Pyx_PyCode_New(3, 0, 4, 0, 0, __pyx_empty_bytes, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_k_tuple_181, __pyx_empty_tuple, __pyx_empty_tuple, __pyx_kp_s_144, __pyx_n_s__span_dec, 2204, __pyx_empty_bytes); if (unlikely(!__pyx_k_codeobj_182)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_RefNannyFinishContext();
   return 0;
   __pyx_L1_error:;
@@ -77236,40 +77349,40 @@ PyMODINIT_FUNC PyInit__sa(void)
   __Pyx_GIVEREF(__pyx_t_3);
   __pyx_t_3 = 0;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2186
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2190
  * 
  * # Spans are _inclusive_ on both ends [i, j]
  * def span_check(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_17span_check, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_17span_check, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_3);
-  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_check, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2186; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_check, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2190; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2194
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2198
  *     return True
  * 
  * def span_inc(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_19span_inc, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_19span_inc, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_3);
-  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_inc, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2194; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_inc, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2198; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
 
-  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2200
+  /* "/home/mdenkows/cdec/python/cdec/sa/rulefactory.pxi":2204
  *         k += 1
  * 
  * def span_dec(vec, i, j):             # <<<<<<<<<<<<<<
  *     k = i
  *     while k <= j:
  */
-  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_21span_dec, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  __pyx_t_3 = PyCFunction_NewEx(&__pyx_mdef_4cdec_2sa_3_sa_21span_dec, NULL, __pyx_n_s_102); if (unlikely(!__pyx_t_3)) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_GOTREF(__pyx_t_3);
-  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_dec, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2200; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
+  if (PyDict_SetItem(__pyx_d, __pyx_n_s__span_dec, __pyx_t_3) < 0) {__pyx_filename = __pyx_f[8]; __pyx_lineno = 2204; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
   __Pyx_DECREF(__pyx_t_3); __pyx_t_3 = 0;
 
   /* "/home/mdenkows/cdec/python/cdec/sa/features.pxi":1
diff --git a/python/cdec/sa/extractor.py b/python/cdec/sa/extractor.py
index 23534712..5a95ded8 100644
--- a/python/cdec/sa/extractor.py
+++ b/python/cdec/sa/extractor.py
@@ -98,3 +98,7 @@ class GrammarExtractor:
         e_words = cdec.sa.encode_words(reference.split())
         al = sorted(tuple(int(i) for i in pair.split('-')) for pair in alignment.split())
         self.factory.add_instance(f_words, e_words, al, ctx_name)
+
+    # Remove all incremental data for a context
+    def drop_ctx(self, ctx_name=None):
+        self.factory.drop_ctx(ctx_name)
diff --git a/python/cdec/sa/rulefactory.pxi b/python/cdec/sa/rulefactory.pxi
index a96b01e7..2be5cad6 100644
--- a/python/cdec/sa/rulefactory.pxi
+++ b/python/cdec/sa/rulefactory.pxi
@@ -2181,6 +2181,10 @@ cdef class HieroCachingRuleFactory:
             extract(f_i, f_i, f_len, -1, 0, 0, [])
 
         return phrases
+
+    # Drop online stats for a context
+    def drop_ctx(self, ctx_name=None):
+        self.online_stats.pop(ctx_name, None)
     
 # Spans are _inclusive_ on both ends [i, j]
 def span_check(vec, i, j):