fixed negative number processing

Author: raydac

src/main/java/com/igormaznitsa/prologparser/terms/PrologFloat.java

@@ -80,4 +80,9 @@ public String toString() {
     final String result = this.value.toEngineeringString();
     return result.indexOf('.') < 0 ? result + ".0" : result;
   }
+
+  @Override
+  public boolean isNegative() {
+    return this.value.signum() < 0;
+  }
 }

src/main/java/com/igormaznitsa/prologparser/terms/PrologInt.java

@@ -113,4 +113,9 @@ public Number getNumber() {
   public BigInteger getIntValue() {
     return this.value;
   }
+
+  @Override
+  public boolean isNegative() {
+    return this.value.signum() < 0;
+  }
 }

src/main/java/com/igormaznitsa/prologparser/terms/PrologNumeric.java

@@ -48,5 +48,7 @@ public String getTermText() {
     return toString();
   }
 
+  public abstract boolean isNegative();
+
   public abstract PrologNumeric neg();
 }

src/main/java/com/igormaznitsa/prologparser/tokenizer/TreeItem.java

@@ -233,7 +233,7 @@ private boolean isOperator() {
 
   @Override
   public String toString() {
-    return savedTerm.toString();
+    return "TreeItem[" + (this.savedTerm == null ? "null" : this.savedTerm.toString()) + ']';
   }
 
   PrologTerm convertToTermAndRelease() {
@@ -298,9 +298,10 @@ PrologTerm convertToTermAndRelease() {
             right = this.rightBranch == null ? null : this.rightBranch.convertToTermAndRelease();
           }
 
-          // this code replaces '-'(number) to '-number'
-          if (right instanceof PrologNumeric && wrapper.getQuotingType() == PrologTerm.QuotingType.NO_QUOTED && left == null && right.getTermType() == TermType.ATOM) {
-            if ("-".equals(wrapper.getTermText())) {
+          // this code replaces '-'(number) to '-number' if number is not negative one
+          if ("-".equals(wrapper.getTermText()) && left == null && right instanceof PrologNumeric) {
+            final PrologNumeric numeric = (PrologNumeric) right;
+            if (!numeric.isNegative()) {
               result = ((PrologNumeric) right).neg();
               break;
             }

src/test/java/com/igormaznitsa/prologparser/IntegrationTest.java

@@ -263,8 +263,6 @@ public void testParseInteger() {
     checkIntegerWithoutPPE("0", 0);
     checkIntegerWithoutPPE("1", 1);
     checkIntegerWithoutPPE("1313", 1313);
-    checkIntegerWithoutPPE("-0", 0);
-    checkIntegerWithoutPPE("-97", -97);
     checkIntegerWithoutPPE("-97", -97);
     checkIntegerWithoutPPE(Long.toString(Long.MAX_VALUE), Long.MAX_VALUE);