Flag to control if keyword terms are allowed

If set, parser instance is no longer fully compliant with the official
CQL grammar but parsing is more strict at disallowing problematic queries.

diff --git a/src/main/java/org/z3950/zing/cql/CQLParser.java b/src/main/java/org/z3950/zing/cql/CQLParser.java
index 6bd6d01..d577cd9 100644 (file)
--- a/src/main/java/org/z3950/zing/cql/CQLParser.java
+++ b/src/main/java/org/z3950/zing/cql/CQLParser.java
@@ -22,12 +22,13 @@ import java.util.Set;
 public class CQLParser {
     private CQLLexer lexer;
     private PositionAwareReader par; //active reader with position
-    private int compat;        // When false, implement CQL 1.2
+    private final int compat;  // When false, implement CQL 1.2
     private final Set<String> customRelations = new HashSet<String>();
     
     public static final int V1POINT1 = 12368;
     public static final int V1POINT2 = 12369;
     public static final int V1POINT1SORT = 12370;
+    public final boolean allowKeywordTerms;
 
     static private boolean DEBUG = false;
     static private boolean LEXDEBUG = false;
@@ -47,13 +48,27 @@ public class CQLParser {
      */
     public CQLParser(int compat) {
        this.compat = compat;
+        this.allowKeywordTerms = true;
     }
-
+    
+    /**
+     * Official CQL grammar allows registered keywords like 'and/or/not/sortby/prox' 
+     * to be used unquoted in terms. This constructor allows to create an instance 
+     * of a parser that prohibits this behavior while sacrificing compatibility.
+     * @param compat CQL version compatibility
+     * @param allowKeywordTerms when false registered keywords are disallowed in unquoted terms
+     */
+    public CQLParser(int compat, boolean allowKeywordTerms) {
+       this.compat = V1POINT2;
+        this.allowKeywordTerms = allowKeywordTerms;
+    }
+    
     /**
      * The new parser implements CQL 1.2
      */
     public CQLParser() {
        this.compat = V1POINT2;
+        this.allowKeywordTerms = true;
     }
 
     private static void debug(String str) {
@@ -340,11 +355,12 @@ public class CQLParser {
            // indexes, terms, prefix names and prefix identifiers.
            // ### Instead, we should ask the lexer whether what we
            // have is a keyword, and let the knowledge reside there.
+            (allowKeywordTerms &&
            lexer.ttype == CQLLexer.TT_AND ||
            lexer.ttype == CQLLexer.TT_OR ||
            lexer.ttype == CQLLexer.TT_NOT ||
            lexer.ttype == CQLLexer.TT_PROX ||
-           lexer.ttype == CQLLexer.TT_SORTBY) {
+           lexer.ttype == CQLLexer.TT_SORTBY)) {
            String symbol = (lexer.ttype == CQLLexer.TT_NUMBER) ?
                lexer.render() : lexer.sval;
            match(lexer.ttype);
@@ -468,7 +484,6 @@ public class CQLParser {
        }
 
        CQLParser parser = new CQLParser(compat);
-        parser.registerCustomRelation("@");
        CQLNode root = null;
        try {
            root = parser.parse(cql);