-// $Id: CQLParser.java,v 1.3 2002-10-24 16:06:34 mike Exp $
+// $Id: CQLParser.java,v 1.22 2002-11-20 01:15:15 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;
-import java.io.IOException;
-import java.io.StringReader;
-import java.io.StreamTokenizer;
/**
- * Compiles a CQL string into a parse tree ...
- * ###
+ * Compiles CQL strings into parse trees of CQLNode subtypes.
*
- * @version $Id: CQLParser.java,v 1.3 2002-10-24 16:06:34 mike Exp $
+ * @version $Id: CQLParser.java,v 1.22 2002-11-20 01:15:15 mike Exp $
* @see <A href="http://zing.z3950.org/cql/index.html"
* >http://zing.z3950.org/cql/index.html</A>
*/
-class CQLCompiler {
- private String cql;
- private String qualset;
- private Properties qualsetProperties;
- private StreamTokenizer st;
-
- private class CQLParseException extends Exception {
- CQLParseException(String s) { super(s); }
- }
+public class CQLParser {
+ private CQLLexer lexer;
+ static private boolean DEBUG = false;
+ static private boolean LEXDEBUG = false;
- public CQLCompiler(String cql, String qualset) {
- this.cql = cql;
- this.qualset = qualset;
+ private static void debug(String str) {
+ if (DEBUG)
+ System.err.println("PARSEDEBUG: " + str);
}
- public String convertToPQN()
- throws FileNotFoundException, IOException {
-
- if (qualsetProperties == null) {
- // ### Could think about caching named qualifier sets
- // across compilations (i.e. shared, in a static
- // Hashtable, between multiple CQLCompiler
- // instances.) Probably not worth it.
- InputStream is = this.getClass().getResourceAsStream(qualset);
- if (is == null)
- throw new FileNotFoundException("getResourceAsStream(" +
- qualset + ")");
- qualsetProperties = new Properties();
- qualsetProperties.load(is);
- }
-
- st = new StreamTokenizer(new StringReader(cql));
- st.wordChars('/', '/');
- st.wordChars('0', '9'); // ### but 1 is still recognised as TT_NUM
- st.wordChars('.', '.');
- st.wordChars('-', '-');
- st.ordinaryChar('=');
- st.ordinaryChar(',');
- st.ordinaryChar('(');
- st.ordinaryChar(')');
-
-// int token;
-// while ((token = st.nextToken()) != st.TT_EOF) {
-// System.out.println("token=" + token + ", " +
-// "nval=" + st.nval + ", " +
-// "sval=" + st.sval);
-// }
-
- st.nextToken();
- String ret;
- try {
- ret = parse_expression();
- } catch (CQLParseException ex) {
- System.err.println("### Oops: " + ex);
- return null;
- }
+ /**
+ * 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);
- if (st.ttype != st.TT_EOF) {
- System.err.println("### Extra bits: " + render(st));
- return null;
- }
+ lexer.nextToken();
+ 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());
- // Interpret attributes as BIB-1 unless otherwise specified
- return "@attrset bib-1 " + ret;
+ return root;
}
- private String parse_expression()
+ private CQLNode parseQuery(String qualifier, CQLRelation relation)
throws CQLParseException, IOException {
- String term = parse_term();
+ debug("in parseQuery()");
- while (st.ttype == st.TT_WORD) {
- String op = st.sval.toLowerCase();
- if (!st.sval.equals("and") &&
- !st.sval.equals("or") &&
- !st.sval.equals("not"))
- break;
- match(st.TT_WORD);
- String term2 = parse_term();
- term = "@" + op + " " + term + " " + term2;
+ 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 = parseTerm(qualifier, relation);
+ term = new CQLAndNode(term, term2);
+ } else if (lexer.ttype == lexer.TT_OR) {
+ match(lexer.TT_OR);
+ CQLNode term2 = parseTerm(qualifier, relation);
+ term = new CQLOrNode(term, term2);
+ } else if (lexer.ttype == lexer.TT_NOT) {
+ match(lexer.TT_NOT);
+ 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 = parseTerm(qualifier, relation);
+ proxnode.addSecondSubterm(term2);
+ term = (CQLNode) proxnode;
+ } else {
+ throw new CQLParseException("expected boolean, got " +
+ lexer.render());
+ }
}
+ debug("no more ops");
return term;
}
- private String parse_term()
+ private CQLNode parseTerm(String qualifier, CQLRelation relation)
throws CQLParseException, IOException {
- if (st.ttype == '(') {
- match('(');
- String expr = parse_expression();
- match(')');
- return expr;
- }
+ debug("in parseTerm()");
- String word = null;
- String attrs = "";
+ String word;
+ while (true) {
+ if (lexer.ttype == '(') {
+ debug("parenthesised term");
+ match('(');
+ CQLNode expr = parseQuery(qualifier, relation);
+ match(')');
+ return expr;
+ } else if (lexer.ttype == '>') {
+ match('>');
+ return parsePrefix(qualifier, relation);
+ }
- // ### We treat ',' and '=' equivalently here, which isn't quite right.
- while (st.ttype == st.TT_WORD) {
- word = st.sval;
- match(st.TT_WORD);
- if (st.ttype != '=' && st.ttype != ',') {
- // end of qualifer list
+ debug("non-parenthesised term");
+ word = matchSymbol("qualifier or term");
+ if (!isBaseRelation())
break;
- }
- String attr = qualsetProperties.getProperty(word);
- if (attr == null) {
- throw new CQLParseException("unrecognised qualifier: " + word);
+ qualifier = word;
+ relation = new CQLRelation(lexer.render(lexer.ttype, false));
+ match(lexer.ttype);
+
+ while (lexer.ttype == '/') {
+ match('/');
+ if (lexer.ttype != lexer.TT_RELEVANT &&
+ lexer.ttype != lexer.TT_FUZZY &&
+ lexer.ttype != lexer.TT_STEM &&
+ lexer.ttype != lexer.TT_PHONETIC)
+ throw new CQLParseException("expected relation modifier, "
+ + "got " + lexer.render());
+ relation.addModifier(lexer.sval.toLowerCase());
+ match(lexer.ttype);
}
- attrs = attrs + attr + " ";
- match(st.ttype);
- word = null; // mark as not-yet-read
+
+ debug("qualifier='" + qualifier + ", " +
+ "relation='" + relation.toCQL() + "'");
}
- if (word == null) {
- // got to the end of a "foo,bar=" sequence
- word = st.sval;
- if (st.ttype != '\'' || st.ttype != '"') {
- word = "\"" + word + "\"";
- match(st.ttype);
- } else {
- match(st.TT_WORD);
+ CQLTermNode node = new CQLTermNode(qualifier, relation, word);
+ debug("made term node " + node.toCQL());
+ 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++) {
+ if (lexer.ttype != '/')
+ return; // end of proximity parameters
+
+ match('/');
+ if (lexer.ttype != '/') {
+ // not an omitted default
+ switch (i) {
+ // 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;
+ case 3: gatherProxOrdering(node); break;
+ }
}
}
+ }
- return attrs + word;
+ 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 match(int token)
+ private void gatherProxDistance(CQLProxNode node)
throws CQLParseException, IOException {
- if (st.ttype != token)
- throw new CQLParseException("expected " + render(st, token, null) +
- ", " + "got " + render(st));
- st.nextToken();
+ 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));
}
- // ### This utility should surely be a method of the StreamTokenizer class
- private static String render(StreamTokenizer st) {
- return render(st, st.ttype, null);
+ 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);
+ }
+
+ 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);
}
- private static String render(StreamTokenizer st, int token, String str) {
- String ret;
+ private 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 ||
+ lexer.ttype == lexer.TT_SCR);
+ }
+
+ // 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 == '<' ||
+ lexer.ttype == '>' ||
+ lexer.ttype == '=' ||
+ lexer.ttype == lexer.TT_LE ||
+ lexer.ttype == lexer.TT_GE ||
+ lexer.ttype == lexer.TT_NE);
+ }
- switch (token) {
- case st.TT_EOF: return "EOF";
- case st.TT_EOL: return "EOL";
- case st.TT_NUMBER: return "number";
- case st.TT_WORD: ret = "word"; break;
- case '"': case '\'': ret = "string"; break;
- default: return "'" + String.valueOf((char) token) + "'";
+ private void match(int token)
+ throws CQLParseException, IOException {
+ debug("in match(" + lexer.render(token, true) + ")");
+ if (lexer.ttype != token)
+ throw new CQLParseException("expected " +
+ lexer.render(token, true) +
+ ", " + "got " + lexer.render());
+ int tmp = lexer.nextToken();
+ debug("match() got token=" + lexer.ttype + ", " +
+ "nval=" + lexer.nval + ", sval='" + lexer.sval + "'" +
+ " (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
+ // qualifiers, 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_ANY ||
+ lexer.ttype == lexer.TT_ALL ||
+ lexer.ttype == lexer.TT_EXACT ||
+ lexer.ttype == lexer.TT_pWORD ||
+ lexer.ttype == lexer.TT_SENTENCE ||
+ lexer.ttype == lexer.TT_PARAGRAPH ||
+ lexer.ttype == lexer.TT_ELEMENT ||
+ lexer.ttype == lexer.TT_ORDERED ||
+ lexer.ttype == lexer.TT_UNORDERED ||
+ lexer.ttype == lexer.TT_RELEVANT ||
+ lexer.ttype == lexer.TT_FUZZY ||
+ lexer.ttype == lexer.TT_STEM ||
+ lexer.ttype == lexer.TT_SCR ||
+ lexer.ttype == lexer.TT_PHONETIC) {
+ String symbol = (lexer.ttype == lexer.TT_NUMBER) ?
+ lexer.render() : lexer.sval;
+ match(lexer.ttype);
+ return symbol;
}
- if (str != null)
- ret += "(\"" + str + "\")";
- return ret;
+ throw new CQLParseException("expected " + expected + ", " +
+ "got " + lexer.render());
}
- // ### Not really the right place for this test harness.
- //
- // e.g. java uk.org.miketaylor.zoom.CQLCompiler
- // '(au=Kerninghan or au=Ritchie) and ti=Unix' qualset.properties
- // yields:
- // @and
- // @or
- // @attr 1=1 @attr 4=1 Kerninghan
- // @attr 1=1 @attr 4=1 Ritchie
- // @attr 1=4 @attr 4=1 Unix
- //
+
+ /**
+ * 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 -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 != 2) {
- System.err.println("Usage: CQLQuery <cql> <qualset>");
+ char mode = 'x'; // x=XCQL, c=CQL, p=PQF
+ String pfile = null;
+
+ Vector argv = new Vector();
+ for (int i = 0; i < args.length; i++) {
+ argv.add(args[i]);
+ }
+
+ 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 [-c] [-p <pqf-properties> [<CQL-query>]");
+ System.err.println("If unspecified, query is read from stdin");
System.exit(1);
}
- CQLCompiler cc = new CQLCompiler(args[0], args[1]);
+ String cql;
+ 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 (IOException ex) {
+ System.err.println("Can't read query: " + ex.getMessage());
+ System.exit(2);
+ }
+ cql = new String(bytes);
+ }
+
+ CQLParser parser = new CQLParser();
+ CQLNode root = null;
try {
- String pqn = cc.convertToPQN();
- System.out.println(pqn);
- } catch (FileNotFoundException ex) {
- System.err.println("Can't find qualifier set: " + ex);
- System.exit(2);
+ root = parser.parse(cql);
+ } catch (CQLParseException ex) {
+ System.err.println("Syntax error: " + ex.getMessage());
+ System.exit(3);
+ } 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 read qualifier set: " + ex);
- System.exit(2);
+ System.err.println("Can't render query: " + ex.getMessage());
+ System.exit(5);
+ } catch (UnknownQualifierException ex) {
+ System.err.println("Unknown qualifier: " + 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");
}
}
}
projects / cql-java-moved-to-github.git / blobdiff