added processing of multi-element error case in list tail

Author: raydac

src/main/java/com/igormaznitsa/prologparser/PrologParser.java

@@ -50,6 +50,8 @@
 
 import static com.igormaznitsa.prologparser.DefaultParserContext.of;
 import static com.igormaznitsa.prologparser.ParserContext.*;
+import static com.igormaznitsa.prologparser.tokenizer.Op.METAOPERATOR_COMMA;
+import static com.igormaznitsa.prologparser.tokenizer.Op.METAOPERATOR_VERTICAL_BAR;
 import static com.igormaznitsa.prologparser.utils.Koi7CharOpMap.ofOps;
 import static java.util.Objects.requireNonNull;
 
@@ -88,7 +90,7 @@ public abstract class PrologParser implements Iterable<PrologTerm>, Closeable {
     META_OP_MAP.add(Op.METAOPERATOR_LEFT_SQUARE_BRACKET);
     OPERATOR_RIGHTSQUAREBRACKET = META_OP_MAP.add(Op.METAOPERATOR_RIGHT_SQUARE_BRACKET);
     OPERATOR_VERTICALBAR = META_OP_MAP.add(Op.METAOPERATOR_VERTICAL_BAR);
-    OPERATOR_COMMA = META_OP_MAP.add(Op.METAOPERATOR_COMMA);
+    OPERATOR_COMMA = META_OP_MAP.add(METAOPERATOR_COMMA);
 
     OPERATORS_PHRASE = ofOps(OPERATOR_DOT);
     OPERATORS_INSIDE_LIST = ofOps(OPERATOR_COMMA, OPERATOR_RIGHTSQUAREBRACKET, OPERATOR_VERTICALBAR);
@@ -108,7 +110,7 @@ public PrologParser(final Reader source, final ParserContext context) {
     this.parserFlags = context == null ? FLAG_NONE : context.getFlags();
   }
 
-  public PrologParser autoCloseReader(){
+  public PrologParser autoCloseReader() {
     this.autoCloseReaderFlag = true;
     return this;
   }
@@ -302,9 +304,21 @@ private PrologTerm readList(final TokenizerResult openingBracket) {
       if (rightPart == null) {
         throw new PrologParserException("There is not any term as the tail at the list", this.tokenizer.getLastTokenLine(), this.tokenizer.getLastTokenPos());
       }
-      if (rightPart.getType() == TermType.ATOM && rightPart.getQuotation() == Quotation.NONE && ",".equals(rightPart.getText())) {
+
+      if (rightPart.getType() == TermType.STRUCT
+          && (rightPart.getFunctor() == METAOPERATOR_COMMA
+          || rightPart.getFunctor() == METAOPERATOR_VERTICAL_BAR)
+      ) {
+        throw new PrologParserException("Unexpected comma or bar in rest of list", this.tokenizer.getLastTokenLine(), this.tokenizer.getLastTokenPos());
+      }
+
+      if (rightPart.getType() == TermType.ATOM
+          && rightPart.getQuotation() == Quotation.NONE
+          && ",".equals(rightPart.getText())
+      ) {
         throw new PrologParserException("Comma operator in list tail", this.tokenizer.getLastTokenLine(), this.tokenizer.getLastTokenPos());
       }
+
       leftPartFirst.replaceEndListElement(rightPart);
     }
     return leftPartFirst;

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

@@ -352,6 +352,12 @@ public void testParseStructure() {
 
   @Test
   public void testParseList() {
+    assertThrows(PrologParserException.class, ()->parseEd("[1,2|3,4].").next());
+    assertThrows(PrologParserException.class, ()->parseEd("[1,2|3,4,5].").next());
+    assertThrows(PrologParserException.class, ()->parseEd("[1,2|3|4].").next());
+    assertThrows(PrologParserException.class, ()->parseEd("[1,2||4].").next());
+    assertThrows(PrologParserException.class, ()->parseEd("[|4].").next());
+
     PrologList list = (PrologList) parseEd("[].").next();
     assertEquals(TermType.LIST, list.getType());
     assertEquals(PrologList.class, list.getClass());

src/test/java/com/igormaznitsa/prologparser/PrologSourceKoi7Generator.java

@@ -181,7 +181,7 @@ private String generateList(final int recusionLevel) {
     for (int i = 0; i < len; i++) {
       if (i != 0) {
         if (i < len - 1 && !tailAdded && this.rnd.nextInt(10) > 8) {
-          builder.append('|');
+          builder.append("|(");
           tailAdded = true;
         } else {
           builder.append(',');
@@ -192,7 +192,7 @@ private String generateList(final int recusionLevel) {
     }
 
 
-    builder.append(']');
+    builder.append(tailAdded ? ")]" : "]");
     return builder.toString();
   }