-// $Id: CQLParser.java,v 1.8 2002-10-27 00:46:25 mike Exp $
+// $Id: CQLParser.java,v 1.10 2002-10-30 09:19:26 mike Exp $
package org.z3950.zing.cql;
-import java.util.Properties;
-import java.io.InputStream;
import java.io.IOException;
-import java.io.StringReader;
-import java.io.StreamTokenizer;
/**
- * Compiles a CQL string into a parse tree ...
+ * Compiles a CQL string into a parse tree.
* ###
*
- * @version $Id: CQLParser.java,v 1.8 2002-10-27 00:46:25 mike Exp $
+ * @version $Id: CQLParser.java,v 1.10 2002-10-30 09:19:26 mike Exp $
* @see <A href="http://zing.z3950.org/cql/index.html"
* >http://zing.z3950.org/cql/index.html</A>
*/
public class CQLParser {
private CQLLexer lexer;
- static private boolean PARSEDEBUG = false;
+ static private boolean DEBUG = false;
static private boolean LEXDEBUG = false;
- private class CQLParseException extends Exception {
- CQLParseException(String s) { super(s); }
- }
-
- static void debug(String str) {
- if (PARSEDEBUG)
+ private static void debug(String str) {
+ if (DEBUG)
System.err.println("PARSEDEBUG: " + str);
}
lexer.nextToken();
debug("about to parse_query()");
- CQLNode root = parse_query("srw.serverChoice", "=");
+ CQLNode root = parse_query("srw.serverChoice", new CQLRelation("="));
if (lexer.ttype != lexer.TT_EOF)
throw new CQLParseException("junk after end: " + lexer.render());
return root;
}
- private CQLNode parse_query(String qualifier, String relation)
+ private CQLNode parse_query(String qualifier, CQLRelation relation)
throws CQLParseException, IOException {
debug("in parse_query()");
CQLNode term = parse_term(qualifier, relation);
- while (lexer.ttype == lexer.TT_WORD) {
- String op = lexer.sval.toLowerCase();
- debug("checking op '" + op + "'");
- if (lexer.sval.equals("and")) {
- match(lexer.TT_WORD);
+ while (lexer.ttype != lexer.TT_EOF &&
+ lexer.ttype != ')') {
+ if (lexer.ttype == lexer.TT_AND) {
+ match(lexer.TT_AND);
CQLNode term2 = parse_term(qualifier, relation);
term = new CQLAndNode(term, term2);
- } else if (lexer.sval.equals("or")) {
- match(lexer.TT_WORD);
+ } else if (lexer.ttype == lexer.TT_OR) {
+ match(lexer.TT_OR);
CQLNode term2 = parse_term(qualifier, relation);
term = new CQLOrNode(term, term2);
- } else if (lexer.sval.equals("not")) {
- match(lexer.TT_WORD);
+ } else if (lexer.ttype == lexer.TT_NOT) {
+ match(lexer.TT_NOT);
CQLNode term2 = parse_term(qualifier, relation);
term = new CQLNotNode(term, term2);
- } else if (lexer.sval.equals("prox")) {
+ } else if (lexer.ttype == lexer.TT_PROX) {
// ### Handle "prox"
} else {
- throw new CQLParseException("unrecognised boolean: '" +
- lexer.sval + "'");
+ throw new CQLParseException("expected boolean, got " +
+ lexer.render());
}
}
return term;
}
- private CQLNode parse_term(String qualifier, String relation)
+ private CQLNode parse_term(String qualifier, CQLRelation relation)
throws CQLParseException, IOException {
debug("in parse_term()");
debug("non-parenthesised term");
word = lexer.sval;
match(lexer.ttype);
- if (!isRelation())
+ if (!isBaseRelation())
break;
qualifier = word;
- relation = lexer.render(false);
+ relation = new CQLRelation(lexer.render(lexer.ttype, false));
match(lexer.ttype);
- debug("qualifier='" + qualifier + ", relation='" + relation + "'");
+
+ while (lexer.ttype == '/') {
+ match('/');
+ // ### could insist on known modifiers only
+ if (lexer.ttype != lexer.TT_WORD)
+ throw new CQLParseException("expected relation modifier, "
+ + "got " + lexer.render());
+ relation.addModifier(lexer.sval);
+ match(lexer.TT_WORD);
+ }
+
+ debug("qualifier='" + qualifier + ", " +
+ "relation='" + relation.toCQL() + "'");
}
CQLTermNode node = new CQLTermNode(qualifier, relation, word);
- debug("made term node " + node);
+ debug("made term node " + node.toCQL());
return node;
}
- boolean isRelation() {
- // ### Also need to handle <=, >=, <>
+ boolean isBaseRelation() {
+ debug("isBaseRelation: checking ttype=" + lexer.ttype +
+ " (" + lexer.render() + ")");
return (lexer.ttype == '<' ||
lexer.ttype == '>' ||
- lexer.ttype == '=');
+ lexer.ttype == '=' ||
+ lexer.ttype == lexer.TT_LE ||
+ lexer.ttype == lexer.TT_GE ||
+ lexer.ttype == lexer.TT_NE ||
+ lexer.ttype == lexer.TT_ANY ||
+ lexer.ttype == lexer.TT_ALL ||
+ lexer.ttype == lexer.TT_EXACT);
}
private void match(int token)
throws CQLParseException, IOException {
- debug("in match(" + lexer.render(token, null, true) + ")");
+ debug("in match(" + lexer.render(token, true) + ")");
if (lexer.ttype != token)
throw new CQLParseException("expected " +
- lexer.render(token, null, true) +
+ lexer.render(token, true) +
", " + "got " + lexer.render());
- lexer.nextToken();
+ int tmp = lexer.nextToken();
+ debug("match() got token=" + lexer.ttype + ", " +
+ "nval=" + lexer.nval + ", sval='" + lexer.sval + "'" +
+ " (tmp=" + tmp + ")");
}
}
}
}
-
-
-// This is a trivial subclass for java.io.StreamTokenizer which knows
-// about the multi-character tokens "<=", ">=" and "<>", and included
-// a render() method. Used only by CQLParser.
-//
-class CQLLexer extends StreamTokenizer {
- private static boolean lexdebug;
-
- CQLLexer(String cql, boolean lexdebug) {
- super(new StringReader(cql));
- this.ordinaryChar('=');
- this.ordinaryChar('<');
- this.ordinaryChar('>');
- this.ordinaryChar('/');
- this.ordinaryChar('(');
- this.ordinaryChar(')');
- this.wordChars('\'', '\''); // prevent this from introducing strings
- this.lexdebug = lexdebug;
- }
-
- public int nextToken() throws java.io.IOException {
- int token = super.nextToken();
- if (lexdebug)
- System.out.println("LEXDEBUG: " +
- "token=" + token + ", " +
- "nval=" + this.nval + ", " +
- "sval=" + this.sval);
-
- return token;
- }
-
- String render() {
- return this.render(this.ttype, null, true);
- }
-
- String render(boolean quoteChars) {
- return this.render(this.ttype, null, quoteChars);
- }
-
- String render(int token, String str, boolean quoteChars) {
- String ret;
-
- if (token == this.TT_EOF) {
- return "EOF";
- } else if (token == this.TT_EOL) {
- return "EOL";
- } else if (token == this.TT_NUMBER) {
- return "number: " + this.nval;
- } else if (token == this.TT_WORD) {
- return "word: \"" + this.sval + "\"";
- } else if (token == '"') {
- return "string: \"" + this.sval + "\"";
- }
-
- String res = String.valueOf((char) token);
- if (quoteChars) res = "'" + res + "'";
- return res;
- }
-}
projects / cql-java-moved-to-github.git / blobdiff