-// $Id: CQLParser.java,v 1.11 2002-10-31 22:22:01 mike Exp $
+// $Id: CQLParser.java,v 1.39 2007-08-06 15:54:48 mike Exp $
package org.z3950.zing.cql;
import java.io.IOException;
+import java.util.Vector;
+import java.util.Properties;
+import java.io.InputStream;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
/**
- * Compiles a CQL string into a parse tree.
- * ##
+ * Compiles CQL strings into parse trees of CQLNode subtypes.
*
- * @version $Id: CQLParser.java,v 1.11 2002-10-31 22:22:01 mike Exp $
+ * @version $Id: CQLParser.java,v 1.39 2007-08-06 15:54:48 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;
+ private int compat; // When false, implement CQL 1.2
+ public static int V1POINT1 = 12368;
+ public static int V1POINT2 = 12369;
+ public static int V1POINT1SORT = 12370;
+
static private boolean DEBUG = false;
static private boolean LEXDEBUG = false;
+ /**
+ * The new parser implements a dialect of CQL specified by the
+ * <tt>compat</tt> argument:
+ * <ul>
+ * <li>V1POINT1 - CQL version 1.1
+ * </li>
+ * <li>V1POINT2 - CQL version 1.2
+ * </li>
+ * <li>V1POINT1SORT - CQL version 1.1 but including
+ * <tt>sortby</tt> as specified for CQL 1.2.
+ * </li>
+ * </ul>
+ */
+ public CQLParser(int compat) {
+ this.compat = compat;
+ }
+
+ /**
+ * The new parser implements CQL 1.2
+ */
+ public CQLParser() {
+ this.compat = V1POINT2;
+ }
+
private static void debug(String str) {
if (DEBUG)
System.err.println("PARSEDEBUG: " + str);
}
+ /**
+ * Compiles a CQL query.
+ * <P>
+ * The resulting parse tree may be further processed by hand (see
+ * the individual node-types' documentation for details on the
+ * data structure) or, more often, simply rendered out in the
+ * desired form using one of the back-ends. <TT>toCQL()</TT>
+ * returns a decompiled CQL query equivalent to the one that was
+ * compiled in the first place; <TT>toXCQL()</TT> returns an
+ * XML snippet representing the query; and <TT>toPQF()</TT>
+ * returns the query rendered in Index Data's Prefix Query
+ * Format.
+ *
+ * @param cql The query
+ * @return A CQLNode object which is the root of a parse
+ * tree representing the query. */
public CQLNode parse(String cql)
throws CQLParseException, IOException {
lexer = new CQLLexer(cql, LEXDEBUG);
lexer.nextToken();
- debug("about to parse_query()");
- CQLNode root = parse_query("srw.serverChoice", new CQLRelation("="));
+ debug("about to parseQuery()");
+ CQLNode root = parseTopLevelPrefixes("cql.serverChoice",
+ new CQLRelation(compat == V1POINT2 ? "=" : "scr"));
if (lexer.ttype != lexer.TT_EOF)
throw new CQLParseException("junk after end: " + lexer.render());
return root;
}
- private CQLNode parse_query(String qualifier, CQLRelation relation)
+ private CQLNode parseTopLevelPrefixes(String index, CQLRelation relation)
+ throws CQLParseException, IOException {
+ debug("top-level prefix mapping");
+
+ if (lexer.ttype == '>') {
+ return parsePrefix(index, relation, true);
+ }
+
+ CQLNode node = parseQuery(index, relation);
+ if ((compat == V1POINT2 || compat == V1POINT1SORT) &&
+ lexer.ttype == lexer.TT_SORTBY) {
+ match(lexer.ttype);
+ debug("sortspec");
+
+ CQLSortNode sortnode = new CQLSortNode(node);
+ while (lexer.ttype != lexer.TT_EOF) {
+ String sortindex = matchSymbol("sort index");
+ ModifierSet ms = gatherModifiers(sortindex);
+ sortnode.addSortIndex(ms);
+ }
+
+ if (sortnode.keys.size() == 0) {
+ throw new CQLParseException("no sort keys");
+ }
+
+ node = sortnode;
+ }
+
+ return node;
+ }
+
+ private CQLNode parseQuery(String index, CQLRelation relation)
throws CQLParseException, IOException {
- debug("in parse_query()");
+ debug("in parseQuery()");
- CQLNode term = parse_term(qualifier, relation);
+ CQLNode term = parseTerm(index, relation);
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.ttype == lexer.TT_OR) {
- match(lexer.TT_OR);
- CQLNode term2 = parse_term(qualifier, relation);
- term = new CQLOrNode(term, term2);
- } 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.ttype == lexer.TT_PROX) {
- match(lexer.TT_PROX);
- CQLProxNode proxnode = new CQLProxNode(term);
- gatherProxParameters(proxnode);
- CQLNode term2 = parse_term(qualifier, relation);
- proxnode.addSecondSubterm(term2);
- term = (CQLNode) proxnode;
+ lexer.ttype != ')' &&
+ lexer.ttype != lexer.TT_SORTBY) {
+ if (lexer.ttype == lexer.TT_AND ||
+ lexer.ttype == lexer.TT_OR ||
+ lexer.ttype == lexer.TT_NOT ||
+ lexer.ttype == lexer.TT_PROX) {
+ int type = lexer.ttype;
+ String val = lexer.sval;
+ match(type);
+ ModifierSet ms = gatherModifiers(val);
+ CQLNode term2 = parseTerm(index, relation);
+ term = ((type == lexer.TT_AND) ? new CQLAndNode(term, term2, ms) :
+ (type == lexer.TT_OR) ? new CQLOrNode (term, term2, ms) :
+ (type == lexer.TT_NOT) ? new CQLNotNode(term, term2, ms) :
+ new CQLProxNode(term, term2, ms));
} else {
throw new CQLParseException("expected boolean, got " +
lexer.render());
return term;
}
- private CQLNode parse_term(String qualifier, CQLRelation relation)
+ private ModifierSet gatherModifiers(String base)
+ throws CQLParseException, IOException {
+ debug("in gatherModifiers()");
+
+ ModifierSet ms = new ModifierSet(base);
+ while (lexer.ttype == '/') {
+ match('/');
+ if (lexer.ttype != lexer.TT_WORD)
+ throw new CQLParseException("expected modifier, "
+ + "got " + lexer.render());
+ String type = lexer.sval.toLowerCase();
+ match(lexer.ttype);
+ if (!isRelation()) {
+ // It's a simple modifier consisting of type only
+ ms.addModifier(type);
+ } else {
+ // It's a complex modifier of the form type=value
+ String comparision = lexer.render(lexer.ttype, false);
+ match(lexer.ttype);
+ String value = matchSymbol("modifier value");
+ ms.addModifier(type, comparision, value);
+ }
+ }
+
+ return ms;
+ }
+
+ private CQLNode parseTerm(String index, CQLRelation relation)
throws CQLParseException, IOException {
- debug("in parse_term()");
+ debug("in parseTerm()");
String word;
while (true) {
if (lexer.ttype == '(') {
debug("parenthesised term");
match('(');
- CQLNode expr = parse_query(qualifier, relation);
+ CQLNode expr = parseQuery(index, relation);
match(')');
return expr;
- } else if (lexer.ttype != lexer.TT_WORD && lexer.ttype != '"') {
- throw new CQLParseException("expected qualifier or term, " +
- "got " + lexer.render());
+ } else if (lexer.ttype == '>') {
+ return parsePrefix(index, relation, false);
}
debug("non-parenthesised term");
- word = lexer.sval;
- match(lexer.ttype);
- if (!isBaseRelation())
+ word = matchSymbol("index or term");
+ if (!isRelation() && lexer.ttype != lexer.TT_WORD)
break;
- qualifier = word;
- relation = new CQLRelation(lexer.render(lexer.ttype, false));
+ index = word;
+ String relstr = (lexer.ttype == lexer.TT_WORD ?
+ lexer.sval : lexer.render(lexer.ttype, false));
+ relation = new CQLRelation(relstr);
match(lexer.ttype);
-
- 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 + ", " +
+ ModifierSet ms = gatherModifiers(relstr);
+ relation.setModifiers(ms);
+ debug("index='" + index + ", " +
"relation='" + relation.toCQL() + "'");
}
- CQLTermNode node = new CQLTermNode(qualifier, relation, word);
+ CQLTermNode node = new CQLTermNode(index, relation, word);
debug("made term node " + node.toCQL());
return node;
}
- private void gatherProxParameters(CQLProxNode node)
+ private CQLNode parsePrefix(String index, CQLRelation relation,
+ boolean topLevel)
throws CQLParseException, IOException {
- for (int i = 0; i < 4; i++) {
- if (lexer.ttype != '/')
- return; // end of proximity parameters
+ debug("prefix mapping");
- match('/');
- if (lexer.ttype != '/') {
- // not an omitted default
- switch (i) {
- // Assumes order is: relation/distance/unit/ordering
- case 0: gatherProxRelation(node); break;
- case 1: gatherProxDistance(node); break;
- case 2: gatherProxUnit(node); break;
- case 3: gatherProxOrdering(node); break;
- }
- }
+ match('>');
+ String name = null;
+ String identifier = matchSymbol("prefix-name");
+ if (lexer.ttype == '=') {
+ match('=');
+ name = identifier;
+ identifier = matchSymbol("prefix-identifer");
}
- }
-
- private void gatherProxRelation(CQLProxNode node)
- throws CQLParseException, IOException {
- if (!isProxRelation())
- throw new CQLParseException("expected proximity relation, got " +
- lexer.render());
- node.addModifier("relation", lexer.render(lexer.ttype, false));
- match(lexer.ttype);
- debug("gPR matched " + lexer.render(lexer.ttype, false));
- }
-
- private void gatherProxDistance(CQLProxNode node)
- throws CQLParseException, IOException {
- if (lexer.ttype != lexer.TT_NUMBER)
- throw new CQLParseException("expected proximity distance, got " +
- lexer.render());
- node.addModifier("distance", lexer.render(lexer.ttype, false));
- match(lexer.ttype);
- debug("gPD matched " + lexer.render(lexer.ttype, false));
- }
-
- private void gatherProxUnit(CQLProxNode node)
- throws CQLParseException, IOException {
- if (lexer.ttype != lexer.TT_pWORD &&
- lexer.ttype != lexer.TT_SENTENCE &&
- lexer.ttype != lexer.TT_PARAGRAPH &&
- lexer.ttype != lexer.TT_ELEMENT)
- throw new CQLParseException("expected proximity unit, got " +
- lexer.render());
- node.addModifier("unit", lexer.render());
- match(lexer.ttype);
- }
+ CQLNode node = topLevel ?
+ parseTopLevelPrefixes(index, relation) :
+ parseQuery(index, relation);
- private void gatherProxOrdering(CQLProxNode node)
- throws CQLParseException, IOException {
- if (lexer.ttype != lexer.TT_ORDERED &&
- lexer.ttype != lexer.TT_UNORDERED)
- throw new CQLParseException("expected proximity ordering, got " +
- lexer.render());
- node.addModifier("ordering", lexer.render());
- match(lexer.ttype);
- }
-
- boolean isBaseRelation() {
- debug("isBaseRelation: checking ttype=" + lexer.ttype +
- " (" + lexer.render() + ")");
- return (isProxRelation() ||
- lexer.ttype == lexer.TT_ANY ||
- lexer.ttype == lexer.TT_ALL ||
- lexer.ttype == lexer.TT_EXACT);
+ return new CQLPrefixNode(name, identifier, node);
}
- boolean isProxRelation() {
- debug("isProxRelation: checking ttype=" + lexer.ttype +
+ // Checks for a relation
+ private boolean isRelation() {
+ debug("isRelation: checking ttype=" + lexer.ttype +
" (" + lexer.render() + ")");
return (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_NE ||
+ lexer.ttype == lexer.TT_EQEQ);
}
private void match(int token)
" (tmp=" + tmp + ")");
}
+ private String matchSymbol(String expected)
+ throws CQLParseException, IOException {
+
+ debug("in matchSymbol()");
+ if (lexer.ttype == lexer.TT_WORD ||
+ lexer.ttype == lexer.TT_NUMBER ||
+ lexer.ttype == '"' ||
+ // The following is a complete list of keywords. Because
+ // they're listed here, they can be used unquoted as
+ // 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.
+ lexer.ttype == lexer.TT_AND ||
+ lexer.ttype == lexer.TT_OR ||
+ lexer.ttype == lexer.TT_NOT ||
+ lexer.ttype == lexer.TT_PROX ||
+ lexer.ttype == lexer.TT_SORTBY) {
+ String symbol = (lexer.ttype == lexer.TT_NUMBER) ?
+ lexer.render() : lexer.sval;
+ match(lexer.ttype);
+ return symbol;
+ }
+
+ throw new CQLParseException("expected " + expected + ", " +
+ "got " + lexer.render());
+ }
+
- // Test harness.
- //
- // e.g. echo '(au=Kerninghan or au=Ritchie) and ti=Unix' |
- // java org.z3950.zing.cql.CQLParser
- // yields:
- // <triple>
- // <boolean>and</boolean>
- // <triple>
- // <boolean>or</boolean>
- // <searchClause>
- // <index>au<index>
- // <relation>=<relation>
- // <term>Kerninghan<term>
- // </searchClause>
- // <searchClause>
- // <index>au<index>
- // <relation>=<relation>
- // <term>Ritchie<term>
- // </searchClause>
- // </triple>
- // <searchClause>
- // <index>ti<index>
- // <relation>=<relation>
- // <term>Unix<term>
- // </searchClause>
- // </triple>
- //
+ /**
+ * Simple test-harness for the CQLParser class.
+ * <P>
+ * Reads a CQL query either from its command-line argument, if
+ * there is one, or standard input otherwise. So these two
+ * invocations are equivalent:
+ * <PRE>
+ * CQLParser 'au=(Kerninghan or Ritchie) and ti=Unix'
+ * echo au=(Kerninghan or Ritchie) and ti=Unix | CQLParser
+ * </PRE>
+ * The test-harness parses the supplied query and renders is as
+ * XCQL, so that both of the invocations above produce the
+ * following output:
+ * <PRE>
+ * <triple>
+ * <boolean>
+ * <value>and</value>
+ * </boolean>
+ * <triple>
+ * <boolean>
+ * <value>or</value>
+ * </boolean>
+ * <searchClause>
+ * <index>au</index>
+ * <relation>
+ * <value>=</value>
+ * </relation>
+ * <term>Kerninghan</term>
+ * </searchClause>
+ * <searchClause>
+ * <index>au</index>
+ * <relation>
+ * <value>=</value>
+ * </relation>
+ * <term>Ritchie</term>
+ * </searchClause>
+ * </triple>
+ * <searchClause>
+ * <index>ti</index>
+ * <relation>
+ * <value>=</value>
+ * </relation>
+ * <term>Unix</term>
+ * </searchClause>
+ * </triple>
+ * </PRE>
+ * <P>
+ * @param -1
+ * CQL version 1.1 (default version 1.2)
+ * @param -d
+ * Debug mode: extra output written to stderr.
+ * @param -c
+ * Causes the output to be written in CQL rather than XCQL - that
+ * is, a query equivalent to that which was input, is output. In
+ * effect, the test harness acts as a query canonicaliser.
+ * @return
+ * The input query, either as XCQL [default] or CQL [if the
+ * <TT>-c</TT> option is supplied].
+ */
public static void main (String[] args) {
- if (args.length > 1) {
- System.err.println("Usage: CQLParser [<CQL-query>]");
+ char mode = 'x'; // x=XCQL, c=CQL, p=PQF
+ String pfile = null;
+
+ Vector<String> argv = new Vector<String>();
+ for (int i = 0; i < args.length; i++) {
+ argv.add(args[i]);
+ }
+
+ int compat = V1POINT2;
+ if (argv.size() > 0 && argv.get(0).equals("-1")) {
+ compat = V1POINT1;
+ argv.remove(0);
+ }
+
+ if (argv.size() > 0 && argv.get(0).equals("-d")) {
+ DEBUG = true;
+ argv.remove(0);
+ }
+
+ if (argv.size() > 0 && argv.get(0).equals("-c")) {
+ mode = 'c';
+ argv.remove(0);
+ } else if (argv.size() > 1 && argv.get(0).equals("-p")) {
+ mode = 'p';
+ argv.remove(0);
+ pfile = (String) argv.get(0);
+ argv.remove(0);
+ }
+
+ if (argv.size() > 1) {
+ System.err.println("Usage: CQLParser [-1] [-d] [-c] " +
+ "[-p <pqf-properties> [<CQL-query>]");
System.err.println("If unspecified, query is read from stdin");
System.exit(1);
}
String cql;
- if (args.length == 1) {
- cql = args[0];
+ if (argv.size() == 1) {
+ cql = (String) argv.get(0);
} else {
byte[] bytes = new byte[10000];
try {
// Read in the whole of standard input in one go
int nbytes = System.in.read(bytes);
- } catch (java.io.IOException ex) {
+ } catch (IOException ex) {
System.err.println("Can't read query: " + ex.getMessage());
System.exit(2);
}
cql = new String(bytes);
}
- CQLParser parser = new CQLParser();
- CQLNode root;
+ CQLParser parser = new CQLParser(compat);
+ CQLNode root = null;
try {
root = parser.parse(cql);
- debug("root='" + root + "'");
- System.out.println(root.toCQL());
} catch (CQLParseException ex) {
System.err.println("Syntax error: " + ex.getMessage());
System.exit(3);
- } catch (java.io.IOException ex) {
+ } catch (IOException ex) {
System.err.println("Can't compile query: " + ex.getMessage());
System.exit(4);
}
+
+ try {
+ if (mode == 'c') {
+ System.out.println(root.toCQL());
+ } else if (mode == 'p') {
+ InputStream f = new FileInputStream(pfile);
+ if (f == null)
+ throw new FileNotFoundException(pfile);
+
+ Properties config = new Properties();
+ config.load(f);
+ f.close();
+ System.out.println(root.toPQF(config));
+ } else {
+ System.out.print(root.toXCQL(0));
+ }
+ } catch (IOException ex) {
+ System.err.println("Can't render query: " + ex.getMessage());
+ System.exit(5);
+ } catch (UnknownIndexException ex) {
+ System.err.println("Unknown index: " + ex.getMessage());
+ System.exit(6);
+ } catch (UnknownRelationException ex) {
+ System.err.println("Unknown relation: " + ex.getMessage());
+ System.exit(7);
+ } catch (UnknownRelationModifierException ex) {
+ System.err.println("Unknown relation modifier: " +
+ ex.getMessage());
+ System.exit(8);
+ } catch (UnknownPositionException ex) {
+ System.err.println("Unknown position: " + ex.getMessage());
+ System.exit(9);
+ } catch (PQFTranslationException ex) {
+ // We catch all of this class's subclasses, so --
+ throw new Error("can't get a PQFTranslationException");
+ }
}
}
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