rdqlparser.java

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/* Generated By:JavaCC: Do not edit this line. RdqlParser.java */
package org.openrdf.sesame.query.rdql.parser;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.openrdf.util.xml.XmlDatatypeUtil;
import org.openrdf.vocabulary.OWL;
import org.openrdf.vocabulary.RDF;
import org.openrdf.vocabulary.RDFS;
import org.openrdf.vocabulary.XmlSchema;

import org.openrdf.model.Literal;
import org.openrdf.model.URI;
import org.openrdf.model.impl.LiteralImpl;
import org.openrdf.model.impl.URIImpl;

import org.openrdf.rio.ntriples.NTriplesUtil;

import org.openrdf.sesame.query.TableQuery;
import org.openrdf.sesame.sail.query.And;
import org.openrdf.sesame.sail.query.BooleanConstant;
import org.openrdf.sesame.sail.query.BooleanExpr;
import org.openrdf.sesame.sail.query.GraphPattern;
import org.openrdf.sesame.sail.query.Like;
import org.openrdf.sesame.sail.query.LiteralExpr;
import org.openrdf.sesame.sail.query.MathExpr;
import org.openrdf.sesame.sail.query.Not;
import org.openrdf.sesame.sail.query.Null;
import org.openrdf.sesame.sail.query.Or;
import org.openrdf.sesame.sail.query.ProjectionElem;
import org.openrdf.sesame.sail.query.Query;
import org.openrdf.sesame.sail.query.ResourceExpr;
import org.openrdf.sesame.sail.query.SelectQuery;
import org.openrdf.sesame.sail.query.StringCompare;
import org.openrdf.sesame.sail.query.StringConstant;
import org.openrdf.sesame.sail.query.TriplePattern;
import org.openrdf.sesame.sail.query.ValueCompare;
import org.openrdf.sesame.sail.query.ValueExpr;
import org.openrdf.sesame.sail.query.Var;

public class RdqlParser implements RdqlParserConstants {

/*----------+
| Constants |
+----------*/

        public static final URI XSD_INTEGER = new URIImpl(XmlSchema.INTEGER);
        public static final URI XSD_FLOAT = new URIImpl(XmlSchema.FLOAT);

/*----------+
| Variables |
+----------*/

        /**
	 * Mapping of prefix to namespace.
	 **/
        protected Map _namespaces = new HashMap(16);

        /**
	 * List of shared variables. Named variables are shared; multiple
	 * occurrences of the name of one variable in a query represent
	 * the same variable.
	 **/
        protected List _sharedVars = new ArrayList(16);

        /**
	 * Anonymous variable identifier.
	 **/
        protected int _varNo = 0;

/*-------------------------------+
| Methods                        |
+-------------------------------*/

        /**
	 * Adds a mapping from the specified prefix to the specified
	 * namespace. The specified prefix must already be mapped to some
	 * (other) namespace.
	 *
	 * @return true if the mapping has been added, false otherwise.
	 * @exception ParseException If the specified prefix is already
	 * mapped to some (other) namespace.
	 **/
        protected void _setNamespacePrefix(String prefix, String namespace)
                throws ParseException
        {
                if (_namespaces.containsKey(prefix)) {
                        // Prefix already defined, report this error.
                        throw new ParseException("Prefix \"" + prefix + "\" already in use.");
                }

                _namespaces.put(prefix, namespace);
        }

        /**
	 * Gets the namespace that is mapped to the supplied prefix.
	 **/
        protected String _getNamespace(String prefix) {
                String result = (String)_namespaces.get(prefix);

                // rdf, rdfs, xsd and owl are default
                // namespace when not defined explicitly.
                if (result == null) {
                        if ("rdf".equals(prefix)) {
                                result = RDF.NAMESPACE;
                        }
                        else if ("rdfs".equals(prefix)) {
                                result = RDFS.NAMESPACE;
                        }
                        else if ("xsd".equals(prefix)) {
                                result = XmlSchema.NAMESPACE;
                        }
                        else if ("owl".equals(prefix)) {
                                result = OWL.NAMESPACE;
                        }
                }

                return result;
        }

        /**
	 * Returns the shared instance of Var that is associated with the
	 * specified variable name. A new shared variable will be created
	 * whenever this method is called with a new variable name.
	 **/
        protected Var _getSharedVar(String varName) {
                Var var;

                // Search for a variable with the supplied name in _sharedVars
                Iterator i = _sharedVars.iterator();
                while (i.hasNext()) {
                        var = (Var)i.next();
                        if (var.getName().equals(varName)) {
                                // Variable found
                                return var;
                        }
                }

                // Variable does not exist; create one and add it to a number of lists
                var = new Var(varName);
                _sharedVars.add(var);

                return var;
        }

        /**
	 * Creates a new anonymous variable and returns it.
	 **/
        protected Var _createAnonymousVar() {
                Var result = new Var("_" + _varNo++);
                result.setAnonymous(true);
                return result;
        }

        /**
	 * Parses a string representating of full or abbreviated URI and
	 * creates a URI object from it.
	 **/
        protected URI _parseURI(String uri)
                throws ParseException
        {
                if (uri.startsWith("<")) {
                        return _parseQuotedURI(uri);
                }
                else {
                        return _parseQName(uri);
                }
        }

        /**
	 * Parses a quoted URI (i.e. <tt>&lt;http://foo/bar&gt;</tt>) and creates a
	 * URI object for it.
	 **/
        protected URI _parseQuotedURI(String uri)
                throws ParseException
        {
                // Full URI starts with "<" and ends with ">", remove these characters.
                try {
                        uri = uri.substring(1, uri.length() - 1);

                        // Substitute any prefixes with their associated namespace
                        int colonIdx = uri.indexOf(':');
                        if (colonIdx > 0) {
                                String prefix = uri.substring(0, colonIdx);
                                String localName = uri.substring(colonIdx + 1);

                                String namespace = _getNamespace(prefix);

                                if (namespace != null) {
                                        // Rebuild URI using namespace and localname
                                        uri = namespace + localName;
                                }
                        }

                        return new URIImpl(uri);
                }
                catch (IllegalArgumentException e) {
                        // Not a valid, fully qualified URI
                        throw new ParseException(e.getMessage());
                }
        }

        /**
	 * Parses a string representing an abbreviated URI (i.e.
	 * <tt>rdf:type</tt>) and creates a URI object for it.
	 **/
        protected URI _parseQName(String uri)
                throws ParseException
        {
                // QNames have the form PREFIX:LNAME, substitute the PREFIX
                // with an actual namespace.

                int colonIdx = uri.indexOf(':');

                String prefix = uri.substring(0, colonIdx);
                String localName = uri.substring(colonIdx + 1);

                String namespace = _getNamespace(prefix);

                if (namespace == null) {
                        throw new ParseException("Prefix \"" + prefix + "\" not defined.");
                }

                return new URIImpl(namespace + localName);
        }

        /**
	 * Parses a new Literal from the supplied String.
	 **/
        protected Literal _parseLiteral(String literal)
                throws ParseException
        {
                // Find string separation points
                int endLabelIdx = _findEndOfLabel(literal);
                int startLangIdx = literal.indexOf("@", endLabelIdx);
                int startDtIdx = literal.indexOf("^^", Math.max(endLabelIdx, startLangIdx));

                // Get label
                String label = literal.substring(1, endLabelIdx);
                label = NTriplesUtil.unescapeString(label);

                if (startLangIdx != -1) {
                        // Get language
                        String language = literal.substring(startLangIdx + 1);
                        return new LiteralImpl(label, language);
                }
                else if (startDtIdx != -1) {
                        // Get datatype
                        String dtString = literal.substring(startDtIdx + 2);
                        URI datatype = _parseURI(dtString);

                        // Normalize label when datatype is XML Schema built-in
                        if (XmlDatatypeUtil.isBuiltInDatatype(datatype.getURI())) {
                                try {
                                        label = XmlDatatypeUtil.normalize(label, datatype.getURI());
                                }
                                catch (IllegalArgumentException e) {
                                        throw new ParseException(e.getMessage());
                                }
                        }

                        return new LiteralImpl(label, datatype);
                }
                else {
                        return new LiteralImpl(label);
                }
        }

        /**
	 * Finds the end of the label in a literal string. This method
	 * takes into account that characters can be escaped using
	 * backslashes.
	 *
	 * @return The index of the double quote ending the label.
	 **/
        private int _findEndOfLabel(String literal)
                throws ParseException
        {
                // First character of literal is guaranteed to be a double
                // quote, start search at second character.

                boolean previousWasBackslash = false;

                for (int i = 1; i < literal.length(); i++) {
                        char c = literal.charAt(i);

                        if (c == '"' && !previousWasBackslash) {
                                return i;
                        }
                        else if (c == '\\' && !previousWasBackslash) {
                                // start of escape
                                previousWasBackslash = true;
                        }
                        else if (previousWasBackslash) {
                                // c was escaped
                                previousWasBackslash = false;
                        }
                }

                throw new ParseException("Could not find end of literal label");
        }

        /**
	 * Creates a new ParseException with the supplied current and
	 * expected tokens. See ParseException for details.
	 **/
        protected ParseException _createParseException(
                Token currentTokenVal, String[] tokenImage)
        {
                // Append "<EOF>" in front of the supplied String array.
                // ParseException.getMessage expects "<EOF>" as the first String
                // in the String array.
                int length = tokenImage.length;

                // New String array has one element extra, therefore length of
                // new String array is increased by one.
                String[] newTokenImage = new String[length + 1];

                // First element is "<EOF>"
                newTokenImage[0] = "<EOF>";

                // Copy Strings of the supplied String array to the new String array.
                for (int i = 0; i < length; i++) {
                        newTokenImage[i +1] = tokenImage[i];
                }

                int[][] expectedTokenSequences = new int[1][length];

                for (int i = 0; i < length; i++) {
                        expectedTokenSequences [0][i] = i +1;
                }

                return new ParseException(currentTokenVal, expectedTokenSequences, newTokenImage);
        }

  final public TableQuery parseQuery() throws ParseException {
        Query qc;
    switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
    case PREFIXES:
      prefixes_clause();
      break;
    default:
      jj_la1[0] = jj_gen;
      ;
    }
    qc = select_query();
    jj_consume_token(0);
                        {if (true) return new TableQuery(qc);}
    throw new Error("Missing return statement in function");
  }

  final public void comma_opt() throws ParseException {
    switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
    case COMMA:
      jj_consume_token(COMMA);
      break;
    default:
      jj_la1[1] = jj_gen;
      ;
    }
  }

/*-------------------------------+
| NAMESPACE DECLARATIONS         |
+-------------------------------*/
  final public void prefixes_clause() throws ParseException {
    jj_consume_token(PREFIXES);
    prefix_decl();
    label_1:
    while (true) {
      switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
      case COMMA:
      case NCNAME:
        ;
        break;
      default:
        jj_la1[2] = jj_gen;
        break label_1;
      }
      comma_opt();
      prefix_decl();
    }
  }

  final public void prefix_decl() throws ParseException {
        Token prefixToken;
        ResourceExpr uri;
    prefixToken = jj_consume_token(NCNAME);
    jj_consume_token(FOR);
    uri = quoted_uri();
                        String prefix = prefixToken.image;
                        _setNamespacePrefix(prefix, uri.getString());
  }

  final public Query select_query() throws ParseException {
        List projection;
        GraphPattern graphPattern = new GraphPattern();
    jj_consume_token(SELECT);
    projection = projection();
    switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
    case SOURCE:
    case FROM:
      switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
      case SOURCE:
        jj_consume_token(SOURCE);
        break;
      case FROM:
        jj_consume_token(FROM);
        break;
      default:
        jj_la1[3] = jj_gen;
        jj_consume_token(-1);
        throw new ParseException();
      }
      jj_consume_token(QUOTED_URI);
      label_2:
      while (true) {
        switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
        case COMMA:
        case QUOTED_URI:
          ;
          break;
        default:
          jj_la1[4] = jj_gen;
          break label_2;
        }
        comma_opt();
        jj_consume_token(QUOTED_URI);
      }
      break;
    default:
      jj_la1[5] = jj_gen;
      ;
    }
    jj_consume_token(WHERE);
    triple_pattern_clause(graphPattern);
    switch ((jj_ntk==-1)?jj_ntk():jj_ntk) {
    case SUCHTHAT:
      jj_consume_token(SUCHTHAT);
      constraint_clause(graphPattern);
      break;
    default:
      jj_la1[6] = jj_gen;
      ;