Fixed conversion of oidless single-dependent-empty-tuple atoms

Author: ZOUG

PSOA2X/src/main/antlr3/org/ruleml/psoa/psoa2x/psoa2prolog/PrologConverter.g

@@ -283,7 +283,8 @@ tuple returns [boolean isDependent]
           DEPSIGN  { $isDependent = $DEPSIGN.text.equals("+"); }
           (term { append(","); })*)
     {
-       trimEnd(1);
+    	if (peekEnd(1).equals(","))  // Use trimEnd() only for trimming preceding comma, e.g. not for '(' in the conversion of p(+[])
+       		trimEnd(1);
     }
     ;
 

PSOA2X/src/main/antlr3/org/ruleml/psoa/psoa2x/psoa2tptp/TPTPConverter.g

@@ -310,7 +310,8 @@ tuple returns [boolean isDependent]
           DEPSIGN  { $isDependent = $DEPSIGN.text.equals("+"); }
           (term { append(","); })*)
     {
-       trimEnd(1);
+    	if (peekEnd(1).equals(","))  // Use trimEnd() only for trimming preceding comma, e.g. not for '(' in the conversion of p(+[])
+       		trimEnd(1);
     }
     ;
 

PSOA2X/src/main/java/org/ruleml/psoa/psoa2x/common/ANTLRBasedTranslator.java

@@ -177,6 +177,10 @@ protected BufferIndex getBufferIndex()
 			return index;
 		}
 
+		protected String peekEnd(int len) {
+			return m_buffer.substring(m_buffer.length() - len);
+		}
+		
 		protected void replace(BufferIndex startIndex, int offset, String s) {
 			int end = startIndex.value + offset;
 			m_buffer.replace(startIndex.value, end, s);

PSOATransRun/test/empty-tuples/empty-tuples-KB.psoa

@@ -19,5 +19,22 @@ RuleML (
             o#p(+[] +[a] +[a b] +[a b c] -[] -[a] -[a b] -[a b c])
         )
     )
+    r()
+    r(+[])
+    r(-[])
+    r(a)
+    r(+[a])
+    r(-[a])
+    r(a b)
+    r(+[a b])
+    r(-[a b])
+    r(a b c)
+    r(+[a b c])
+    r(-[a b c])
+    r(+[] +[a] +[a b] +[a b c] -[] -[a] -[a b] -[a b c])
+    s(+[]) :-
+        And(r(-[])
+            r(+[] +[a] +[a b] +[a b c] -[] -[a] -[a b] -[a b c])
+        )
   )
 )

PSOATransRun/test/empty-tuples/empty-tuples-answer4.psoa

@@ -0,0 +1 @@
+yes

PSOATransRun/test/empty-tuples/empty-tuples-answer5.psoa

@@ -0,0 +1 @@
+yes

PSOATransRun/test/empty-tuples/empty-tuples-query4.psoa

@@ -0,0 +1 @@
+And(r() r(+[]) r(-[]) r(+[a]) r(a) r(+[] +[a] -[] -[a]))

PSOATransRun/test/empty-tuples/empty-tuples-query5.psoa

@@ -0,0 +1 @@
+s(+[])