Added the once predicate

fairlight1337 · Oct 12, 2016 · c324edd · c324edd
1 parent 94de9cb
commit c324edd
Showing 1 changed file with 30 additions and 14 deletions.
diff --git a/src/gdaplanner/Prolog.cpp b/src/gdaplanner/Prolog.cpp
@@ -268,21 +268,37 @@ namespace gdaplanner {
 	  }
 	}
       } else if(exQueryBound.match("(not ?a)", mapResolution)) {
-          if(solPrior.index() == -1) {
-            Expression exA = mapResolution["?a"];
-            Solution solTemp;
-
-              try {
-                solTemp = this->unify(exA, solPrior, bdgBindings);
-              } catch(SolutionsExhausted seException) {
-                solTemp.setValid(false);
-              }
+	if(solPrior.index() == -1) {
+	  Expression exA = mapResolution["?a"];
+	  Solution solTemp;
 
-              if(!solTemp.valid()) {
-                solResult = Solution();
-                solResult.index() = 0;
-              }
-            }
+	  try {
+	    solTemp = this->unify(exA, solPrior, bdgBindings);
+	  } catch(SolutionsExhausted seException) {
+	    solTemp.setValid(false);
+	  }
+
+	  if(!solTemp.valid()) {
+	    solResult = Solution();
+	    solResult.index() = 0;
+	  }
+	}
+      } else if(exQueryBound.match("(once ?a)", mapResolution)) {
+	if(solPrior.index() == -1) {
+	  Expression exA = mapResolution["?a"];
+	  Solution solTemp;
+
+	  try {
+	    solTemp = this->unify(exA, solPrior, bdgBindings);
+	  } catch(SolutionsExhausted seException) {
+	    solTemp.setValid(false);
+	  }
+
+	  if(solTemp.valid()) {
+	    solResult = solTemp;
+	    solResult.index() = 0;
+	  }
+	}
       } else if(exQueryBound.match("(1- ?value ?newvalue)", mapResolution)) {
           Expression exValue = mapResolution["?value"];
           Expression exNewValue = mapResolution["?newvalue"];