X-Git-Url: http://jsfdemo.indexdata.com/?a=blobdiff_plain;f=src%2Forg%2Fz3950%2Fzing%2Fcql%2FCQLParser.java;h=13e505e9bb0f34f863a034005c2bb7f2bdda7958;hb=18405938a115378cc571d697060ac40775c62fb7;hp=0aded47d1785d238da77fc5658171bd1fbd67594;hpb=f8154c71944186a9b64ddb782082a2026c5a912f;p=cql-java-moved-to-github.git diff --git a/src/org/z3950/zing/cql/CQLParser.java b/src/org/z3950/zing/cql/CQLParser.java index 0aded47..13e505e 100644 --- a/src/org/z3950/zing/cql/CQLParser.java +++ b/src/org/z3950/zing/cql/CQLParser.java @@ -1,14 +1,18 @@ -// $Id: CQLParser.java,v 1.11 2002-10-31 22:22:01 mike Exp $ +// $Id: CQLParser.java,v 1.23 2003-09-04 21:56:46 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 1.23 2003-09-04 21:56:46 mike Exp $ * @see http://zing.z3950.org/cql/index.html */ @@ -22,43 +26,59 @@ public class CQLParser { System.err.println("PARSEDEBUG: " + str); } + /** + * Compiles a CQL query. + *
+ * 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. toCQL()
+ * returns a decompiled CQL query equivalent to the one that was
+ * compiled in the first place; toXCQL() returns an
+ * XML snippet representing the query; and toPQF()
+ * 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 = parseQuery("srw.serverChoice", new CQLRelation("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 parseQuery(String qualifier, CQLRelation relation)
throws CQLParseException, IOException {
- debug("in parse_query()");
+ debug("in parseQuery()");
- CQLNode term = parse_term(qualifier, relation);
+ CQLNode term = parseTerm(qualifier, 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);
+ CQLNode term2 = parseTerm(qualifier, relation);
term = new CQLAndNode(term, term2);
} else if (lexer.ttype == lexer.TT_OR) {
match(lexer.TT_OR);
- CQLNode term2 = parse_term(qualifier, relation);
+ CQLNode term2 = parseTerm(qualifier, relation);
term = new CQLOrNode(term, term2);
} else if (lexer.ttype == lexer.TT_NOT) {
match(lexer.TT_NOT);
- CQLNode term2 = parse_term(qualifier, relation);
+ CQLNode term2 = parseTerm(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);
+ CQLNode term2 = parseTerm(qualifier, relation);
proxnode.addSecondSubterm(term2);
term = (CQLNode) proxnode;
} else {
@@ -71,41 +91,51 @@ public class CQLParser {
return term;
}
- private CQLNode parse_term(String qualifier, CQLRelation relation)
+ private CQLNode parseTerm(String qualifier, 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(qualifier, 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 == '>') {
+ match('>');
+ return parsePrefix(qualifier, relation);
}
debug("non-parenthesised term");
- word = lexer.sval;
- match(lexer.ttype);
+ word = matchSymbol("qualifier or term");
if (!isBaseRelation())
break;
qualifier = word;
- relation = new CQLRelation(lexer.render(lexer.ttype, false));
+ relation = new CQLRelation(lexer.ttype == lexer.TT_WORD ?
+ lexer.sval :
+ lexer.render(lexer.ttype, false));
match(lexer.ttype);
while (lexer.ttype == '/') {
match('/');
- // ### could insist on known modifiers only
- if (lexer.ttype != lexer.TT_WORD)
+ if (lexer.ttype != lexer.TT_RELEVANT &&
+ lexer.ttype != lexer.TT_FUZZY &&
+ lexer.ttype != lexer.TT_STEM &&
+ lexer.ttype != lexer.TT_PHONETIC &&
+ lexer.ttype != lexer.TT_WORD)
throw new CQLParseException("expected relation modifier, "
+ "got " + lexer.render());
- relation.addModifier(lexer.sval);
- match(lexer.TT_WORD);
+ if (lexer.ttype == lexer.TT_WORD &&
+ lexer.sval.indexOf('.') == -1)
+ throw new CQLParseException("unknown first-class " +
+ "relation modifier: " +
+ lexer.sval);
+
+ relation.addModifier(lexer.sval.toLowerCase());
+ match(lexer.ttype);
}
debug("qualifier='" + qualifier + ", " +
@@ -117,6 +147,21 @@ public class CQLParser {
return node;
}
+ private CQLNode parsePrefix(String qualifier, CQLRelation relation)
+ throws CQLParseException, IOException {
+ debug("prefix mapping");
+
+ String name = null;
+ String identifier = matchSymbol("prefix-name");
+ if (lexer.ttype == '=') {
+ match('=');
+ name = identifier;
+ identifier = matchSymbol("prefix-identifer");
+ }
+ CQLNode term = parseQuery(qualifier, relation);
+ return new CQLPrefixNode(name, identifier, term);
+ }
+
private void gatherProxParameters(CQLProxNode node)
throws CQLParseException, IOException {
for (int i = 0; i < 4; i++) {
@@ -127,7 +172,8 @@ public class CQLParser {
if (lexer.ttype != '/') {
// not an omitted default
switch (i) {
- // Assumes order is: relation/distance/unit/ordering
+ // Order should be: relation/distance/unit/ordering
+ // For now, use MA's: unit/relation/distance/ordering
case 0: gatherProxRelation(node); break;
case 1: gatherProxDistance(node); break;
case 2: gatherProxUnit(node); break;
@@ -179,16 +225,26 @@ public class CQLParser {
match(lexer.ttype);
}
- boolean isBaseRelation() {
+ private boolean isBaseRelation()
+ throws CQLParseException {
debug("isBaseRelation: checking ttype=" + lexer.ttype +
" (" + lexer.render() + ")");
+
+ if (lexer.ttype == lexer.TT_WORD &&
+ lexer.sval.indexOf('.') == -1)
+ throw new CQLParseException("unknown first-class relation: " +
+ lexer.sval);
+
return (isProxRelation() ||
lexer.ttype == lexer.TT_ANY ||
lexer.ttype == lexer.TT_ALL ||
- lexer.ttype == lexer.TT_EXACT);
+ lexer.ttype == lexer.TT_EXACT ||
+ lexer.ttype == lexer.TT_SCR ||
+ lexer.ttype == lexer.TT_WORD);
}
- boolean isProxRelation() {
+ // Checks for a relation that may be used inside a prox operator
+ private boolean isProxRelation() {
debug("isProxRelation: checking ttype=" + lexer.ttype +
" (" + lexer.render() + ")");
return (lexer.ttype == '<' ||
@@ -212,50 +268,137 @@ public class CQLParser {
" (tmp=" + tmp + ")");
}
+ private String matchSymbol(String expected)
+ throws CQLParseException, IOException {
- // Test harness.
- //
- // e.g. echo '(au=Kerninghan or au=Ritchie) and ti=Unix' |
- // java org.z3950.zing.cql.CQLParser
- // yields:
- //
+ * Reads a CQL query either from its command-line argument, if + * there is one, or standard input otherwise. So these two + * invocations are equivalent: + *
+ * CQLParser 'au=(Kerninghan or Ritchie) and ti=Unix' + * echo au=(Kerninghan or Ritchie) and ti=Unix | CQLParser + *+ * The test-harness parses the supplied query and renders is as + * XCQL, so that both of the invocations above produce the + * following output: + *
+ * <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> + *+ *
+ * @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
+ * -c option is supplied].
+ */
public static void main (String[] args) {
- if (args.length > 1) {
- System.err.println("Usage: CQLParser [