libtracker-data: Drop old SPARQL parser

4 files changed, 0 insertions, 4491 deletions

diff --git a/src/libtracker-data/meson.build b/src/libtracker-data/meson.build
index 9eaef5bf1..18f1a481e 100644
--- a/src/libtracker-data/meson.build
+++ b/src/libtracker-data/meson.build
@@ -3,9 +3,6 @@
 # libtracker-sparql-query.
 libtracker_data_vala = static_library('tracker-sparql-query',
     'tracker-vala-namespace.vala',
-    'tracker-sparql-query.vala',
-    'tracker-sparql-expression.vala',
-    'tracker-sparql-pattern.vala',
     'tracker-sparql-scanner.vala',
     'tracker-turtle-reader.vala',
     '../libtracker-common/libtracker-common.vapi',
diff --git a/src/libtracker-data/tracker-sparql-expression.vala b/src/libtracker-data/tracker-sparql-expression.vala
deleted file mode 100644
index ed2a2c74a..000000000
--- a/src/libtracker-data/tracker-sparql-expression.vala
+++ /dev/null
@@ -1,1727 +0,0 @@
-/*
- * Copyright (C) 2008-2010, Nokia
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA  02110-1301, USA.
- */
-
-class Tracker.Sparql.Expression : Object {
-	weak Query query;
-
-	const int MAX_VARIABLES_FOR_IN = 20;
-	const string XSD_NS = "http://www.w3.org/2001/XMLSchema#";
-	const string FN_NS = "http://www.w3.org/2005/xpath-functions#";
-	const string FTS_NS = "http://www.tracker-project.org/ontologies/fts#";
-	const string TRACKER_NS = "http://www.tracker-project.org/ontologies/tracker#";
-
-	enum TimeFormatType {
-		SECONDS,
-		MINUTES,
-		HOURS
-	}
-
-	string? fts_sql;
-
-        Data.Manager manager;
-
-	public Expression (Query query) {
-		this.query = query;
-                this.manager = query.manager;
-	}
-
-	Context context {
-		get { return query.context; }
-	}
-
-	Pattern pattern {
-		get { return query.pattern; }
-	}
-
-	private inline bool next () throws Sparql.Error {
-		return query.next ();
-	}
-
-	private inline SparqlTokenType current () {
-		return query.current ();
-	}
-
-	private inline SparqlTokenType last () {
-		return query.last ();
-	}
-
-	private inline bool accept (SparqlTokenType type) throws Sparql.Error {
-		return query.accept (type);
-	}
-
-	private Sparql.Error get_error (string msg) {
-		return query.get_error (msg);
-	}
-
-	private bool expect (SparqlTokenType type) throws Sparql.Error {
-		return query.expect (type);
-	}
-
-	private string get_last_string (int strip = 0) {
-		return query.get_last_string (strip);
-	}
-
-	private string escape_sql_string_literal (string literal) {
-		return "'%s'".printf (string.joinv ("''", literal.split ("'")));
-	}
-
-	private bool maybe_numeric (PropertyType type) {
-		return (type == PropertyType.INTEGER || type == PropertyType.DOUBLE || type == PropertyType.DATE || type == PropertyType.DATETIME || type == PropertyType.UNKNOWN);
-	}
-
-	private void append_collate (StringBuilder sql) {
-		sql.append_printf (" COLLATE %s", COLLATION_NAME);
-	}
-
-	private void skip_bracketted_expression () throws Sparql.Error {
-		expect (SparqlTokenType.OPEN_PARENS);
-		while (true) {
-			switch (current ()) {
-			case SparqlTokenType.OPEN_PARENS:
-				// skip nested bracketted expression
-				skip_bracketted_expression ();
-				continue;
-			case SparqlTokenType.CLOSE_PARENS:
-			case SparqlTokenType.EOF:
-				break;
-			default:
-				next ();
-				continue;
-			}
-			break;
-		}
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	internal void skip_select_variables () throws Sparql.Error {
-		while (true) {
-			switch (current ()) {
-			case SparqlTokenType.OPEN_PARENS:
-				skip_bracketted_expression ();
-				continue;
-			case SparqlTokenType.FROM:
-			case SparqlTokenType.WHERE:
-			case SparqlTokenType.OPEN_BRACE:
-			case SparqlTokenType.GROUP:
-			case SparqlTokenType.ORDER:
-			case SparqlTokenType.LIMIT:
-			case SparqlTokenType.OFFSET:
-			case SparqlTokenType.EOF:
-				break;
-			default:
-				next ();
-				continue;
-			}
-			break;
-		}
-	}
-
-	internal PropertyType translate_select_expression (StringBuilder sql, bool subquery, int variable_index) throws Sparql.Error {
-		Variable variable = null;
-		bool expect_close_parens = false;
-		bool as_handled = false;
-
-		long begin = sql.len;
-		var type = PropertyType.UNKNOWN;
-		if (current () == SparqlTokenType.VAR) {
-			type = translate_expression (sql);
-			// we need variable name in case of compositional subqueries
-			variable = context.get_variable (get_last_string ().substring (1));
-
-			if (variable.binding == null) {
-				throw get_error ("use of undefined variable `%s'".printf (variable.name));
-			}
-		} else if (accept (SparqlTokenType.OPEN_PARENS)) {
-			if (current () == SparqlTokenType.SELECT) {
-				// no parenthesis around expression
-				// deprecated but supported for backward compatibility
-				sql.append ("(");
-				var select_context = pattern.translate_select (sql, true, true);
-				sql.append (")");
-
-				expect (SparqlTokenType.CLOSE_PARENS);
-				type = select_context.type;
-			} else {
-				type = translate_expression (sql);
-				if (accept (SparqlTokenType.CLOSE_PARENS)) {
-					// missing AS
-					// deprecated but supported for backward compatibility
-				} else {
-					// syntax from SPARQL 1.1 Draft
-					// (Expression AS Var)
-					expect_close_parens = true;
-				}
-			}
-		} else {
-			// no parenthesis around expression
-			// deprecated but supported for backward compatibility
-			type = translate_expression (sql);
-		}
-
-		if (!subquery) {
-			convert_expression_to_string (sql, type, begin);
-		}
-
-		if (accept (SparqlTokenType.AS)) {
-			// (...) AS ?foo
-			expect (SparqlTokenType.VAR);
-			variable = context.get_variable (get_last_string ().substring (1));
-			sql.append_printf (" AS %s", variable.sql_expression);
-			as_handled = true;
-
-			if (subquery) {
-				var binding = new VariableBinding ();
-				binding.data_type = type;
-				binding.variable = variable;
-				binding.sql_expression = variable.sql_expression;
-				pattern.add_variable_binding (new StringBuilder (), binding, VariableState.BOUND);
-			}
-		}
-
-		if (pattern.fts_subject != null) {
-			if (variable == null) {
-				// FTS matches still need aliases as the outer MATCH query
-				// will fetch futher values from the joined select
-				variable = context.get_variable ("var%d".printf (variable_index + 1));
-			}
-
-			if (fts_sql == null) {
-				pattern.fts_variables += variable.sql_expression;
-
-				if (as_handled == false) {
-					sql.append_printf (" AS %s", variable.sql_expression);
-				}
-			} else {
-				pattern.fts_variables += fts_sql;
-				pattern.queries_fts_data = true;
-			}
-		}
-
-		if (expect_close_parens) {
-			expect (SparqlTokenType.CLOSE_PARENS);
-		}
-
-		if (variable != null) {
-			int state = context.var_set.lookup (variable);
-			if (state == 0) {
-				state = VariableState.BOUND;
-			}
-			context.select_var_set.insert (variable, state);
-
-			((SelectContext) context).variable_names += variable.name;
-		} else {
-			((SelectContext) context).variable_names += "var%d".printf (variable_index + 1);
-		}
-
-		fts_sql = null;
-
-		return type;
-	}
-
-	private void translate_expression_as_order_condition (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		if (translate_expression (sql) == PropertyType.RESOURCE) {
-			// ID => Uri
-			sql.insert (begin, "(SELECT Uri FROM Resource WHERE ID = ");
-			sql.append (")");
-		}
-	}
-
-	internal void translate_order_condition (StringBuilder sql) throws Sparql.Error {
-		if (accept (SparqlTokenType.ASC)) {
-			translate_expression_as_order_condition (sql);
-			sql.append (" ASC");
-		} else if (accept (SparqlTokenType.DESC)) {
-			translate_expression_as_order_condition (sql);
-			sql.append (" DESC");
-		} else {
-			translate_expression_as_order_condition (sql);
-		}
-	}
-
-	private void translate_bound_call (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.BOUND);
-		expect (SparqlTokenType.OPEN_PARENS);
-		sql.append ("(");
-		translate_expression (sql);
-		sql.append (" IS NOT NULL)");
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	private PropertyType translate_if_call (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.IF);
-		expect (SparqlTokenType.OPEN_PARENS);
-
-		// condition
-		sql.append ("(CASE ");
-		translate_expression (sql);
-
-		// if condition is true
-		sql.append (" WHEN 1 THEN ");
-		expect (SparqlTokenType.COMMA);
-		var type = translate_expression (sql);
-
-		// if condition is false
-		sql.append (" WHEN 0 THEN ");
-		expect (SparqlTokenType.COMMA);
-		translate_expression (sql);
-
-		sql.append (" ELSE NULL END)");
-
-		expect (SparqlTokenType.CLOSE_PARENS);
-
-		return type;
-	}
-
-	private void translate_regex (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.REGEX);
-		expect (SparqlTokenType.OPEN_PARENS);
-		sql.append ("SparqlRegex(");
-		translate_expression_as_string (sql);
-		sql.append (", ");
-		expect (SparqlTokenType.COMMA);
-		// SQLite's sqlite3_set_auxdata doesn't work correctly with bound
-		// strings for the regex in function_sparql_regex.
-		// translate_expression (sql);
-		sql.append (escape_sql_string_literal (parse_string_literal ()));
-		sql.append (", ");
-		if (accept (SparqlTokenType.COMMA)) {
-			// Same as above
-			// translate_expression (sql);
-			sql.append (escape_sql_string_literal (parse_string_literal ()));
-		} else {
-			sql.append ("''");
-		}
-		sql.append (")");
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	private void translate_exists (StringBuilder sql) throws Sparql.Error {
-		sql.append ("(");
-		pattern.translate_exists (sql);
-		sql.append (")");
-	}
-
-	internal static void append_expression_as_string (StringBuilder sql, string expression, PropertyType type) {
-		long begin = sql.len;
-		sql.append (expression);
-		convert_expression_to_string (sql, type, begin);
-	}
-
-	private static void convert_expression_to_string (StringBuilder sql, PropertyType type, long begin) {
-		switch (type) {
-		case PropertyType.STRING:
-		case PropertyType.INTEGER:
-			// nothing to convert
-			// do not use CAST to convert integers to strings as this breaks use
-			// of index when sorting by variable introduced in select expression
-			break;
-		case PropertyType.RESOURCE:
-			// ID => Uri
-			sql.insert (begin, "(SELECT Uri FROM Resource WHERE ID = ");
-			sql.append (")");
-			break;
-		case PropertyType.BOOLEAN:
-			// 0/1 => false/true
-			sql.insert (begin, "CASE ");
-			sql.append (" WHEN 1 THEN 'true' WHEN 0 THEN 'false' ELSE NULL END");
-			break;
-		case PropertyType.DATE:
-			// ISO 8601 format
-			sql.insert (begin, "strftime (\"%Y-%m-%d\", ");
-			sql.append (", \"unixepoch\")");
-			break;
-		case PropertyType.DATETIME:
-			// ISO 8601 format
-			sql.insert (begin, "SparqlFormatTime (");
-			sql.append (")");
-			break;
-		default:
-			// let sqlite convert the expression to string
-			sql.insert (begin, "CAST (");
-			sql.append (" AS TEXT)");
-			break;
-		}
-	}
-
-	private void translate_expression_as_string (StringBuilder sql) throws Sparql.Error {
-		switch (current ()) {
-		case SparqlTokenType.IRI_REF:
-		case SparqlTokenType.PN_PREFIX:
-		case SparqlTokenType.COLON:
-			// handle IRI literals separately as it wouldn't work for unknown IRIs otherwise
-			var binding = new LiteralBinding ();
-			bool is_var;
-			binding.literal = pattern.parse_var_or_term (null, out is_var);
-			if (accept (SparqlTokenType.OPEN_PARENS)) {
-				// function call
-				long begin = sql.len;
-				var type = translate_function (sql, binding.literal);
-				expect (SparqlTokenType.CLOSE_PARENS);
-				convert_expression_to_string (sql, type, begin);
-			} else {
-				sql.append ("?");
-				query.bindings.append (binding);
-			}
-			break;
-		default:
-			long begin = sql.len;
-			var type = translate_expression (sql);
-			convert_expression_to_string (sql, type, begin);
-			break;
-		}
-	}
-
-	private void translate_str (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.STR);
-		expect (SparqlTokenType.OPEN_PARENS);
-
-		translate_expression_as_string (sql);
-
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	private void translate_isuri (StringBuilder sql) throws Sparql.Error {
-		if (!accept (SparqlTokenType.ISURI)) {
-			expect (SparqlTokenType.ISIRI);
-		}
-
-		expect (SparqlTokenType.OPEN_PARENS);
-
-		sql.append ("?");
-		var new_binding = new LiteralBinding ();
-		new_binding.data_type = PropertyType.INTEGER;
-
-		if (current() == SparqlTokenType.IRI_REF) {
-			new_binding.literal = "1";
-			next ();
-		} else if (translate_expression (new StringBuilder ()) == PropertyType.RESOURCE) {
-			new_binding.literal = "1";
-		} else {
-			new_binding.literal = "0";
-		}
-
-		query.bindings.append (new_binding);
-
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	private void translate_datatype (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.DATATYPE);
-		expect (SparqlTokenType.OPEN_PARENS);
-
-		if (accept (SparqlTokenType.VAR)) {
-			string variable_name = get_last_string().substring(1);
-			var variable = context.get_variable (variable_name);
-
-			if (variable.binding == null) {
-				throw get_error ("`%s' is not a valid variable".printf (variable.name));
-			}
-
-			if (variable.binding.data_type == PropertyType.RESOURCE || variable.binding.type == null) {
-				throw get_error ("Invalid FILTER");
-			}
-
-			sql.append ("(SELECT ID FROM Resource WHERE Uri = ?)");
-
-			var new_binding = new LiteralBinding ();
-			new_binding.literal = variable.binding.type.uri;
-			query.bindings.append (new_binding);
-
-		} else {
-			throw get_error ("Invalid FILTER");
-		}
-
-		expect (SparqlTokenType.CLOSE_PARENS);
-	}
-
-	private void translate_date (StringBuilder sql, string format) throws Sparql.Error {
-		sql.append_printf ("strftime (\"%s\", ", format);
-
-		if (accept (SparqlTokenType.VAR)) {
-			string variable_name = get_last_string ().substring (1);
-			var variable = context.get_variable (variable_name);
-			sql.append (variable.get_extra_sql_expression ("localDate"));
-			sql.append (" * 24 * 3600");
-		} else {
-			translate_primary_expression (sql);
-		}
-
-		sql.append (", \"unixepoch\")");
-	}
-
-	private void translate_time (StringBuilder sql, TimeFormatType type) throws Sparql.Error {
-		sql.append ("(");
-		if (accept (SparqlTokenType.VAR)) {
-			string variable_name = get_last_string ().substring (1);
-			var variable = context.get_variable (variable_name);
-			sql.append (variable.get_extra_sql_expression ("localTime"));
-		} else {
-			translate_primary_expression (sql);
-		}
-
-		switch (type) {
-		case TimeFormatType.SECONDS:
-			sql.append ("% 60");
-			break;
-		case TimeFormatType.MINUTES:
-			sql.append (" / 60 % 60");
-			break;
-		case TimeFormatType.HOURS:
-			sql.append (" / 3600 % 24");
-			break;
-		}
-		sql.append (")");
-	}
-
-	private PropertyType translate_function (StringBuilder sql, string uri) throws Sparql.Error {
-		if (uri == XSD_NS + "string") {
-			// conversion to string
-			translate_expression_as_string (sql);
-
-			return PropertyType.STRING;
-		} else if (uri == XSD_NS + "integer") {
-			// conversion to integer
-			sql.append ("CAST (");
-			translate_expression_as_string (sql);
-			sql.append (" AS INTEGER)");
-
-			return PropertyType.INTEGER;
-		} else if (uri == XSD_NS + "double") {
-			// conversion to double
-			sql.append ("CAST (");
-			translate_expression_as_string (sql);
-			sql.append (" AS REAL)");
-
-			return PropertyType.DOUBLE;
-		} else if (uri == TRACKER_NS + "case-fold") {
-			// conversion to string
-			sql.append ("SparqlCaseFold (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "ascii-lower-case") {
-			// conversion to string
-			sql.append ("lower (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "title-order") {
-			translate_expression_as_string (sql);
-			sql.append_printf (" COLLATE %s", TITLE_COLLATION_NAME);
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "lower-case") {
-			// conversion to string
-			sql.append ("SparqlLowerCase (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "upper-case") {
-			sql.append ("SparqlUpperCase (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "normalize") {
-			// conversion to string
-			sql.append ("SparqlNormalize (");
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "unaccent") {
-			// conversion to string
-			sql.append ("SparqlUnaccent (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "contains") {
-			// fn:contains('A','B') => 'A' GLOB '*B*'
-			sql.append ("(");
-			translate_expression_as_string (sql);
-			sql.append (" GLOB ");
-			expect (SparqlTokenType.COMMA);
-
-			sql.append ("?");
-			var binding = new LiteralBinding ();
-			binding.literal = "*%s*".printf (parse_string_literal ());
-			query.bindings.append (binding);
-
-			sql.append (")");
-
-			return PropertyType.BOOLEAN;
-		} else if (uri == FN_NS + "starts-with") {
-			// fn:starts-with('A','B') => 'A' BETWEEN 'B' AND 'B\u0010fffd'
-			// 0010fffd always sorts last
-
-			translate_expression_as_string (sql);
-			sql.append (" BETWEEN ");
-
-			expect (SparqlTokenType.COMMA);
-			string prefix = parse_string_literal ();
-
-			sql.append ("?");
-			var binding = new LiteralBinding ();
-			binding.literal = prefix;
-			query.bindings.append (binding);
-
-			sql.append (" AND ");
-
-			sql.append ("?");
-			binding = new LiteralBinding ();
-			binding.literal = prefix + COLLATION_LAST_CHAR.to_string ();
-			query.bindings.append (binding);
-
-			return PropertyType.BOOLEAN;
-		} else if (uri == FN_NS + "ends-with") {
-			// fn:ends-with('A','B') => 'A' GLOB '*B'
-			sql.append ("(");
-			translate_expression_as_string (sql);
-			sql.append (" GLOB ");
-			expect (SparqlTokenType.COMMA);
-
-			sql.append ("?");
-			var binding = new LiteralBinding ();
-			binding.literal = "*%s".printf (parse_string_literal ());
-			query.bindings.append (binding);
-
-			sql.append (")");
-
-			return PropertyType.BOOLEAN;
-		} else if (uri == FN_NS + "substring") {
-			sql.append ("substr(");
-			translate_expression_as_string (sql);
-
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-
-			if (accept (SparqlTokenType.COMMA)) {
-			      sql.append (", ");
-			      translate_expression_as_string (sql);
-			}
-
-			sql.append (")");
-
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "concat") {
-			translate_expression_as_string (sql);
-			sql.append ("||");
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-			while (accept (SparqlTokenType.COMMA)) {
-			      sql.append ("||");
-			      translate_expression_as_string (sql);
-			}
-
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "string-join") {
-			sql.append ("SparqlStringJoin(");
-			expect (SparqlTokenType.OPEN_PARENS);
-
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-			while (accept (SparqlTokenType.COMMA)) {
-			      sql.append (", ");
-			      translate_expression_as_string (sql);
-			}
-
-			expect (SparqlTokenType.CLOSE_PARENS);
-			sql.append (",");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (")");
-
-			return PropertyType.STRING;
-		} else if (uri == FN_NS + "year-from-dateTime") {
-			translate_date (sql, "%Y");
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "month-from-dateTime") {
-			translate_date (sql, "%m");
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "day-from-dateTime") {
-			translate_date (sql, "%d");
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "hours-from-dateTime") {
-			translate_time (sql, TimeFormatType.HOURS);
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "minutes-from-dateTime") {
-			translate_time (sql, TimeFormatType.MINUTES);
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "seconds-from-dateTime") {
-			translate_time (sql, TimeFormatType.SECONDS);
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "timezone-from-dateTime") {
-			expect (SparqlTokenType.VAR);
-			string variable_name = get_last_string ().substring (1);
-			var variable = context.get_variable (variable_name);
-
-			sql.append ("(");
-			sql.append (variable.get_extra_sql_expression ("localDate"));
-			sql.append (" * 24 * 3600 + ");
-			sql.append (variable.get_extra_sql_expression ("localTime"));
-			sql.append ("- ");
-			sql.append ("CAST (");
-			sql.append (variable.sql_expression);
-			sql.append (" AS INTEGER)");
-			sql.append (")");
-
-			return PropertyType.INTEGER;
-		} else if (uri == FN_NS + "replace") {
-			sql.append ("SparqlReplace(");
-			translate_expression_as_string (sql);
-			sql.append (", ");
-
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-			sql.append (", ");
-
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-
-			if (accept (SparqlTokenType.COMMA)) {
-				sql.append (", ");
-				sql.append (escape_sql_string_literal (parse_string_literal ()));
-			}
-			sql.append (")");
-			return PropertyType.STRING;
-		} else if (uri == FTS_NS + "rank") {
-			bool is_var;
-			string v = pattern.parse_var_or_term (null, out is_var);
-			sql.append_printf ("\"%s_u_rank\"", v);
-
-			return PropertyType.DOUBLE;
-		} else if (uri == FTS_NS + "offsets") {
-			bool is_var;
-			string v = pattern.parse_var_or_term (null, out is_var);
-			var variable = context.get_variable (v);
-
-			sql.append (variable.sql_expression);
-			fts_sql = "tracker_offsets(\"fts5\")";
-			return PropertyType.STRING;
-		} else if (uri == FTS_NS + "snippet") {
-			bool is_var;
-
-			string v = pattern.parse_var_or_term (null, out is_var);
-			var variable = context.get_variable (v);
-			var fts = new StringBuilder ();
-
-			fts.append_printf ("snippet(\"fts5\"");
-
-			// lookup column
-			fts.append (", -1");
-
-			// "start match" text
-			if (accept (SparqlTokenType.COMMA)) {
-				fts.append (", ");
-				translate_expression_as_string (fts);
-
-				// "end match" text
-				expect (SparqlTokenType.COMMA);
-				fts.append (", ");
-				translate_expression_as_string (fts);
-			} else {
-				fts.append(",'',''");
-			}
-
-			// "ellipsis" text
-			if (accept (SparqlTokenType.COMMA)) {
-				fts.append (", ");
-				translate_expression_as_string (fts);
-			} else {
-				fts.append (", '...'");
-			}
-
-			// Approximate number of words in context
-			if (accept (SparqlTokenType.COMMA)) {
-				fts.append (", ");
-				translate_expression_as_string (fts);
-			} else {
-				fts.append (", 5");
-			}
-
-			fts.append (")");
-
-			fts_sql = fts.str;
-			sql.append (variable.sql_expression);
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "id") {
-			var type = translate_expression (sql);
-			if (type != PropertyType.RESOURCE) {
-				throw get_error ("expected resource");
-			}
-
-			return PropertyType.INTEGER;
-		} else if (uri == TRACKER_NS + "uri") {
-			var type = translate_expression (sql);
-			if (type != PropertyType.INTEGER) {
-				throw get_error ("expected integer ID");
-			}
-
-			return PropertyType.RESOURCE;
-		} else if (uri == TRACKER_NS + "cartesian-distance") {
-			sql.append ("SparqlCartesianDistance(");
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (")");
-
-			return PropertyType.DOUBLE;
-		} else if (uri == TRACKER_NS + "haversine-distance") {
-			sql.append ("SparqlHaversineDistance(");
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (")");
-
-			return PropertyType.DOUBLE;
-		} else if (uri == TRACKER_NS + "coalesce") {
-			sql.append ("COALESCE(");
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression_as_string (sql);
-			while (accept (SparqlTokenType.COMMA)) {
-			      sql.append (", ");
-			      translate_expression_as_string (sql);
-			}
-			sql.append (")");
-
-			return PropertyType.STRING;
-		} else if (uri == TRACKER_NS + "uri-is-parent") {
-			sql.append ("SparqlUriIsParent(");
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-
-			translate_expression_as_string (sql);
-			sql.append (")");
-
-			return PropertyType.BOOLEAN;
-		} else if (uri == TRACKER_NS + "uri-is-descendant") {
-			sql.append ("SparqlUriIsDescendant(");
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-
-                        translate_expression_as_string (sql);
-                        while (accept (SparqlTokenType.COMMA)) {
-			      sql.append (", ");
-			      translate_expression_as_string (sql);
-			}
-			sql.append (")");
-
-			return PropertyType.BOOLEAN;
-		} else if (uri == TRACKER_NS + "string-from-filename") {
-			sql.append ("SparqlStringFromFilename(");
-			translate_expression_as_string (sql);
-			sql.append (")");
-
-			return PropertyType.STRING;
-		} else {
-			// support properties as functions
-                        var ontologies = manager.get_ontologies ();
-			var prop = ontologies.get_property_by_uri (uri);
-			if (prop == null) {
-				throw get_error ("Unknown function");
-			}
-
-			var expr = new StringBuilder ();
-			translate_expression (expr);
-
-			string value_separator = ",";
-			string? graph_separator = null;
-
-			if (accept (SparqlTokenType.COMMA)) {
-				value_separator = parse_string_literal ();
-
-				if (accept (SparqlTokenType.COMMA)) {
-					graph_separator = parse_string_literal ();
-				}
-			}
-
-			if (prop.multiple_values) {
-				// multi-valued property
-				sql.append ("(SELECT GROUP_CONCAT(");
-				long begin = sql.len;
-				sql.append_printf ("\"%s\"", prop.name);
-				convert_expression_to_string (sql, prop.data_type, begin);
-				if (graph_separator != null) {
-					sql.append_printf (" || %s || COALESCE((SELECT Uri FROM Resource WHERE ID = \"%s:graph\"), '')", escape_sql_string_literal (graph_separator), prop.name);
-				}
-				sql.append_printf (",%s)", escape_sql_string_literal (value_separator));
-				sql.append_printf (" FROM \"%s\" WHERE ID = %s)", prop.table_name, expr.str);
-
-				return PropertyType.STRING;
-			} else {
-				// single-valued property
-				if (graph_separator == null) {
-					sql.append_printf ("(SELECT \"%s\" FROM \"%s\" WHERE ID = %s)", prop.name, prop.table_name, expr.str);
-
-					if (prop.data_type == PropertyType.STRING) {
-						append_collate (sql);
-					}
-
-					return prop.data_type;
-				} else {
-					sql.append ("(SELECT ");
-					long begin = sql.len;
-					sql.append_printf ("\"%s\"", prop.name);
-					convert_expression_to_string (sql, prop.data_type, begin);
-					sql.append_printf (" || %s || COALESCE((SELECT Uri FROM Resource WHERE ID = \"%s:graph\"), '')", escape_sql_string_literal (graph_separator), prop.name);
-					sql.append_printf (" FROM \"%s\" WHERE ID = %s)", prop.table_name, expr.str);
-
-					return PropertyType.STRING;
-				}
-			}
-		}
-	}
-
-	private PropertyType parse_type_uri () throws Sparql.Error {
-		string type_iri;
-		PropertyType type;
-
-		if (accept (SparqlTokenType.IRI_REF)) {
-			type_iri = get_last_string (1);
-		} else if (accept (SparqlTokenType.PN_PREFIX)) {
-			string ns = get_last_string ();
-			expect (SparqlTokenType.COLON);
-			type_iri = query.resolve_prefixed_name (ns, get_last_string ().substring (1));
-		} else {
-			expect (SparqlTokenType.COLON);
-			type_iri = query.resolve_prefixed_name ("", get_last_string ().substring (1));
-		}
-
-		if (type_iri == XSD_NS + "boolean") {
-			type = PropertyType.BOOLEAN;
-		} else if (type_iri == XSD_NS + "integer" ||
-		           type_iri == XSD_NS + "nonPositiveInteger" ||
-		           type_iri == XSD_NS + "negativeInteger" ||
-		           type_iri == XSD_NS + "long" ||
-		           type_iri == XSD_NS + "int" ||
-		           type_iri == XSD_NS + "short" ||
-		           type_iri == XSD_NS + "byte" ||
-		           type_iri == XSD_NS + "nonNegativeInteger" ||
-		           type_iri == XSD_NS + "unsignedLong" ||
-		           type_iri == XSD_NS + "unsignedInt" ||
-		           type_iri == XSD_NS + "unsignedShort" ||
-		           type_iri == XSD_NS + "unsignedByte" ||
-		           type_iri == XSD_NS + "positiveInteger") {
-			type = PropertyType.INTEGER;
-		} else if (type_iri == XSD_NS + "double") {
-			type = PropertyType.DOUBLE;
-		} else if (type_iri == XSD_NS + "date") {
-			type = PropertyType.DATE;
-		} else if (type_iri == XSD_NS + "dateTime") {
-			type = PropertyType.DATETIME;
-		} else {
-			type = PropertyType.STRING;
-		}
-
-		return type;
-	}
-
-	internal string parse_string_literal (out PropertyType type = null) throws Sparql.Error {
-		type = PropertyType.STRING;
-
-		next ();
-		switch (last ()) {
-		case SparqlTokenType.STRING_LITERAL1:
-		case SparqlTokenType.STRING_LITERAL2:
-			var sb = new StringBuilder ();
-
-			string s = get_last_string (1);
-			string* p = s;
-			string* end = p + s.length;
-			while ((long) p < (long) end) {
-				string* q = Posix.strchr (p, '\\');
-				if (q == null) {
-					sb.append_len (p, (long) (end - p));
-					p = end;
-				} else {
-					sb.append_len (p, (long) (q - p));
-					p = q + 1;
-					switch (((char*) p)[0]) {
-					case '\'':
-					case '"':
-					case '\\':
-						sb.append_c (((char*) p)[0]);
-						break;
-					case 'b':
-						sb.append_c ('\b');
-						break;
-					case 'f':
-						sb.append_c ('\f');
-						break;
-					case 'n':
-						sb.append_c ('\n');
-						break;
-					case 'r':
-						sb.append_c ('\r');
-						break;
-					case 't':
-						sb.append_c ('\t');
-						break;
-					case 'u':
-						char* ptr = (char*) p + 1;
-						unichar c = (((unichar) ptr[0].xdigit_value () * 16 + ptr[1].xdigit_value ()) * 16 + ptr[2].xdigit_value ()) * 16 + ptr[3].xdigit_value ();
-						sb.append_unichar (c);
-						p += 4;
-						break;
-					}
-					p++;
-				}
-			}
-
-			if (accept (SparqlTokenType.DOUBLE_CIRCUMFLEX)) {
-				// typed literal
-				type = parse_type_uri ();
-			}
-
-			return sb.str;
-		case SparqlTokenType.STRING_LITERAL_LONG1:
-		case SparqlTokenType.STRING_LITERAL_LONG2:
-			string result = get_last_string (3);
-
-			if (accept (SparqlTokenType.DOUBLE_CIRCUMFLEX)) {
-				// typed literal
-				type = parse_type_uri ();
-			}
-
-			return result;
-		default:
-			throw get_error ("expected string literal");
-		}
-	}
-
-	private PropertyType translate_uri_expression (StringBuilder sql, string uri) throws Sparql.Error {
-		if (accept (SparqlTokenType.OPEN_PARENS)) {
-			// function
-			var result = translate_function (sql, uri);
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		} else {
-			// resource
-			sql.append ("COALESCE((SELECT ID FROM Resource WHERE Uri = ?), 0)");
-			var binding = new LiteralBinding ();
-			binding.literal = uri;
-			query.bindings.append (binding);
-			return PropertyType.RESOURCE;
-		}
-	}
-
-	private PropertyType translate_primary_expression (StringBuilder sql) throws Sparql.Error {
-		PropertyType type;
-
-		switch (current ()) {
-		case SparqlTokenType.OPEN_PARENS:
-			return translate_bracketted_expression (sql);
-		case SparqlTokenType.IRI_REF:
-			next ();
-			return translate_uri_expression (sql, get_last_string (1));
-		case SparqlTokenType.DECIMAL:
-		case SparqlTokenType.DOUBLE:
-			next ();
-
-			if (query.no_cache) {
-				sql.append (get_last_string ());
-			} else {
-				sql.append ("?");
-
-				var binding = new LiteralBinding ();
-				binding.literal = get_last_string ();
-				query.bindings.append (binding);
-			}
-
-			return PropertyType.DOUBLE;
-		case SparqlTokenType.TRUE:
-			next ();
-
-			if (query.no_cache) {
-				sql.append ("1");
-			} else {
-				sql.append ("?");
-
-				var binding = new LiteralBinding ();
-				binding.literal = "1";
-				binding.data_type = PropertyType.INTEGER;
-				query.bindings.append (binding);
-			}
-
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.FALSE:
-			next ();
-
-			if (query.no_cache) {
-				sql.append ("0");
-			} else {
-				sql.append ("?");
-
-				var binding = new LiteralBinding ();
-				binding.literal = "0";
-				binding.data_type = PropertyType.INTEGER;
-				query.bindings.append (binding);
-			}
-
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.STRING_LITERAL1:
-		case SparqlTokenType.STRING_LITERAL2:
-		case SparqlTokenType.STRING_LITERAL_LONG1:
-		case SparqlTokenType.STRING_LITERAL_LONG2:
-			var literal = parse_string_literal (out type);
-
-			switch (type) {
-			case PropertyType.INTEGER:
-			case PropertyType.BOOLEAN:
-			case PropertyType.DOUBLE:
-			case PropertyType.DATE:
-			case PropertyType.DATETIME:
-				if (query.no_cache) {
-					sql.append (escape_sql_string_literal (literal));
-				} else {
-					var binding = new LiteralBinding ();
-					binding.literal = literal;
-					binding.data_type = type;
-					query.bindings.append (binding);
-					sql.append ("?");
-				}
-				return type;
-			default:
-				if (query.no_cache) {
-					sql.append (escape_sql_string_literal (literal));
-				} else {
-					var binding = new LiteralBinding ();
-					binding.literal = literal;
-					query.bindings.append (binding);
-					sql.append ("?");
-				}
-				append_collate (sql);
-				return PropertyType.STRING;
-			}
-		case SparqlTokenType.INTEGER:
-			next ();
-
-			if (query.no_cache) {
-				sql.append (get_last_string ());
-			} else {
-				sql.append ("?");
-
-				var binding = new LiteralBinding ();
-				binding.literal = get_last_string ();
-				binding.data_type = PropertyType.INTEGER;
-				query.bindings.append (binding);
-			}
-
-			return PropertyType.INTEGER;
-		case SparqlTokenType.VAR:
-			next ();
-			string variable_name = get_last_string ().substring (1);
-			var variable = context.get_variable (variable_name);
-
-			if (context.need_binding_expression && variable.binding != null) {
-				sql.append (variable.binding.sql_expression);
-			} else {
-				sql.append (variable.sql_expression);
-			}
-
-			if (variable.binding == null) {
-				return PropertyType.UNKNOWN;
-			} else {
-				if (variable.binding.data_type == PropertyType.STRING) {
-					append_collate (sql);
-				}
-				return variable.binding.data_type;
-			}
-		case SparqlTokenType.STR:
-			translate_str (sql);
-			return PropertyType.STRING;
-		case SparqlTokenType.LANG:
-			next ();
-			sql.append ("''");
-			return PropertyType.STRING;
-		case SparqlTokenType.LANGMATCHES:
-			next ();
-			sql.append ("0");
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.DATATYPE:
-			translate_datatype (sql);
-			return PropertyType.RESOURCE;
-		case SparqlTokenType.BOUND:
-			translate_bound_call (sql);
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.COALESCE:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, TRACKER_NS + "coalesce");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.CONCAT:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "concat");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.CONTAINS:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "contains");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.ENCODE_FOR_URI:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			sql.append ("SparqlEncodeForUri (");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.STRING;
-		case SparqlTokenType.IF:
-			return translate_if_call (sql);
-		case SparqlTokenType.SAMETERM:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			sql.append ("(");
-			translate_expression (sql);
-			sql.append (" = ");
-			expect (SparqlTokenType.COMMA);
-			translate_expression (sql);
-			sql.append (")");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.ISIRI:
-		case SparqlTokenType.ISURI:
-			translate_isuri (sql);
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.ISBLANK:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			next ();
-			// TODO: support ISBLANK properly
-			sql.append ("0");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.ISLITERAL:
-			next ();
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.LCASE:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "lower-case");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.UCASE:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "upper-case");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.STRLEN:
-			next ();
-			sql.append ("LENGTH(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return PropertyType.INTEGER;
-		case SparqlTokenType.STRSTARTS:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "starts-with");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.STRENDS:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "ends-with");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.SUBSTR:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "substring");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.STRBEFORE:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			sql.append ("SparqlStringBefore (");
-			translate_expression_as_string (sql);
-			expect (SparqlTokenType.COMMA);
-			sql.append (",");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.STRING;
-		case SparqlTokenType.STRAFTER:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			sql.append ("SparqlStringAfter (");
-			translate_expression_as_string (sql);
-			expect (SparqlTokenType.COMMA);
-			sql.append (",");
-			translate_expression_as_string (sql);
-			sql.append (")");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.STRING;
-		case SparqlTokenType.REGEX:
-			translate_regex (sql);
-			query.no_cache = true;
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.EXISTS:
-		case SparqlTokenType.NOT:
-			translate_exists (sql);
-			return PropertyType.BOOLEAN;
-		case SparqlTokenType.COUNT:
-			next ();
-			sql.append ("COUNT(");
-			translate_aggregate_expression (sql);
-			sql.append (")");
-			return PropertyType.INTEGER;
-		case SparqlTokenType.SUM:
-			next ();
-			sql.append ("SUM(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.AVG:
-			next ();
-			sql.append ("AVG(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.MIN:
-			next ();
-			sql.append ("MIN(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.MAX:
-			next ();
-			sql.append ("MAX(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.ABS:
-			next ();
-			sql.append ("ABS(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.ROUND:
-			next ();
-			sql.append ("ROUND(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.CEIL:
-			next ();
-			sql.append ("SparqlCeil(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.FLOOR:
-			next ();
-			sql.append ("SparqlFloor(");
-			type = translate_aggregate_expression (sql);
-			sql.append (")");
-			return type;
-		case SparqlTokenType.RAND:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			expect (SparqlTokenType.CLOSE_PARENS);
-			sql.append ("SparqlRand()");
-			return PropertyType.DOUBLE;
-		case SparqlTokenType.NOW:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			expect (SparqlTokenType.CLOSE_PARENS);
-			sql.append ("strftime('%s', 'now')");
-			return PropertyType.DATETIME;
-		case SparqlTokenType.SECONDS:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "seconds-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.MINUTES:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "minutes-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.HOURS:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "hours-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.DAY:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "day-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.MONTH:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "month-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.YEAR:
-			next ();
-			expect (SparqlTokenType.OPEN_PARENS);
-			var result = translate_function (sql, FN_NS + "year-from-dateTime");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return result;
-		case SparqlTokenType.MD5:
-			next ();
-			sql.append ("SparqlChecksum(");
-			type = translate_aggregate_expression (sql);
-			sql.append (", \"md5\")");
-			return type;
-		case SparqlTokenType.SHA1:
-			next ();
-			sql.append ("SparqlChecksum(");
-			type = translate_aggregate_expression (sql);
-			sql.append (", \"sha1\")");
-			return type;
-		case SparqlTokenType.SHA256:
-			next ();
-			sql.append ("SparqlChecksum(");
-			type = translate_aggregate_expression (sql);
-			sql.append (", \"sha256\")");
-			return type;
-		case SparqlTokenType.SHA512:
-			next ();
-			sql.append ("SparqlChecksum(");
-			type = translate_aggregate_expression (sql);
-			sql.append (", \"sha512\")");
-			return type;
-		case SparqlTokenType.GROUP_CONCAT:
-			next ();
-			sql.append ("GROUP_CONCAT(");
-			expect (SparqlTokenType.OPEN_PARENS);
-			translate_expression_as_string (sql);
-			sql.append (", ");
-			expect (SparqlTokenType.COMMA);
-			sql.append (escape_sql_string_literal (parse_string_literal ()));
-			sql.append (")");
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return PropertyType.STRING;
-		case SparqlTokenType.PN_PREFIX:
-			next ();
-			string ns = get_last_string ();
-			expect (SparqlTokenType.COLON);
-			string uri = query.resolve_prefixed_name (ns, get_last_string ().substring (1));
-			return translate_uri_expression (sql, uri);
-		case SparqlTokenType.COLON:
-			next ();
-			string uri = query.resolve_prefixed_name ("", get_last_string ().substring (1));
-			return translate_uri_expression (sql, uri);
-		default:
-			throw get_error ("expected primary expression");
-		}
-	}
-
-	PropertyType translate_unary_expression (StringBuilder sql) throws Sparql.Error {
-		if (accept (SparqlTokenType.OP_NEG)) {
-			sql.append ("NOT (");
-			var optype = translate_primary_expression (sql);
-			sql.append (")");
-			if (optype != PropertyType.BOOLEAN) {
-				throw get_error ("expected boolean expression");
-			}
-			return PropertyType.BOOLEAN;
-		} else if (accept (SparqlTokenType.PLUS)) {
-			return translate_primary_expression (sql);
-		} else if (accept (SparqlTokenType.MINUS)) {
-			sql.append ("-(");
-			var optype = translate_primary_expression (sql);
-			sql.append (")");
-			return optype;
-		}
-		return translate_primary_expression (sql);
-	}
-
-	private PropertyType translate_multiplicative_expression (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		var optype = translate_unary_expression (sql);
-		while (true) {
-			if (accept (SparqlTokenType.STAR)) {
-				if (!maybe_numeric (optype)) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.insert (begin, "(");
-				sql.append (" * ");
-				if (!maybe_numeric (translate_unary_expression (sql))) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.append (")");
-			} else if (accept (SparqlTokenType.DIV)) {
-				if (!maybe_numeric (optype)) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.insert (begin, "(");
-				sql.append (" / ");
-				if (!maybe_numeric (translate_unary_expression (sql))) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.append (")");
-			} else {
-				break;
-			}
-		}
-		return optype;
-	}
-
-	private PropertyType translate_additive_expression (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		var optype = translate_multiplicative_expression (sql);
-		while (true) {
-			if (accept (SparqlTokenType.PLUS)) {
-				if (!maybe_numeric (optype)) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.insert (begin, "(");
-				sql.append (" + ");
-				if (!maybe_numeric (translate_multiplicative_expression (sql))) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.append (")");
-			} else if (accept (SparqlTokenType.MINUS)) {
-				if (!maybe_numeric (optype)) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.insert (begin, "(");
-				sql.append (" - ");
-				if (!maybe_numeric (translate_multiplicative_expression (sql))) {
-					throw get_error ("expected numeric operand");
-				}
-				sql.append (")");
-			} else {
-				break;
-			}
-		}
-		return optype;
-	}
-
-	private PropertyType translate_numeric_expression (StringBuilder sql) throws Sparql.Error {
-		return translate_additive_expression (sql);
-	}
-
-	private PropertyType process_relational_expression (StringBuilder sql, long begin, uint n_bindings, PropertyType op1type, string operator) throws Sparql.Error {
-		sql.insert (begin, "(");
-		sql.append (operator);
-		var op2type = translate_numeric_expression (sql);
-		sql.append (")");
-		if ((op1type == PropertyType.DATETIME && op2type == PropertyType.STRING)
-		    || (op1type == PropertyType.STRING && op2type == PropertyType.DATETIME)) {
-			// TODO: improve performance (linked list)
-			if (query.bindings.length () == n_bindings + 1) {
-				// trigger string => datetime conversion
-				query.bindings.last ().data.data_type = PropertyType.DATETIME;
-			}
-		} else if ((op1type == PropertyType.DATE && op2type == PropertyType.STRING)
-		           || (op1type == PropertyType.STRING && op2type == PropertyType.DATE)) {
-			// TODO: improve performance (linked list)
-			if (query.bindings.length () == n_bindings + 1) {
-				// trigger string => date conversion
-				query.bindings.last ().data.data_type = PropertyType.DATE;
-			}
-		}
-		return PropertyType.BOOLEAN;
-	}
-
-	private PropertyType translate_in (StringBuilder sql, bool not) throws Sparql.Error {
-
-		int in_variable_count = 0;
-
-		if (not) {
-			sql.append (" NOT");
-		}
-
-		expect (SparqlTokenType.OPEN_PARENS);
-		sql.append (" IN (");
-		if (!accept (SparqlTokenType.CLOSE_PARENS)) {
-			in_variable_count++;
-			translate_expression (sql);
-			while (accept (SparqlTokenType.COMMA)) {
-				sql.append (", ");
-
-				in_variable_count++;
-
-				if (in_variable_count > MAX_VARIABLES_FOR_IN && !query.no_cache) {
-					query.no_cache = true;
-				}
-
-				translate_expression (sql);
-			}
-			expect (SparqlTokenType.CLOSE_PARENS);
-		}
-		sql.append (")");
-
-		return PropertyType.BOOLEAN;
-	}
-
-	private PropertyType translate_relational_expression (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		// TODO: improve performance (linked list)
-		uint n_bindings = query.bindings.length ();
-		var optype = translate_numeric_expression (sql);
-		if (accept (SparqlTokenType.OP_GE)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " >= ");
-		} else if (accept (SparqlTokenType.OP_EQ)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " = ");
-		} else if (accept (SparqlTokenType.OP_NE)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " <> ");
-		} else if (accept (SparqlTokenType.OP_LT)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " < ");
-		} else if (accept (SparqlTokenType.OP_LE)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " <= ");
-		} else if (accept (SparqlTokenType.OP_GT)) {
-			return process_relational_expression (sql, begin, n_bindings, optype, " > ");
-		} else if (accept (SparqlTokenType.OP_IN)) {
-			return translate_in (sql, false);
-		} else if (accept (SparqlTokenType.NOT)) {
-			expect (SparqlTokenType.OP_IN);
-			return translate_in (sql, true);
-		}
-		return optype;
-	}
-
-	private PropertyType translate_value_logical (StringBuilder sql) throws Sparql.Error {
-		return translate_relational_expression (sql);
-	}
-
-	private PropertyType translate_conditional_and_expression (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		var optype = translate_value_logical (sql);
-		while (accept (SparqlTokenType.OP_AND)) {
-			if (optype != PropertyType.BOOLEAN) {
-				throw get_error ("expected boolean expression");
-			}
-			sql.insert (begin, "(");
-			sql.append (" AND ");
-			optype = translate_value_logical (sql);
-			sql.append (")");
-			if (optype != PropertyType.BOOLEAN) {
-				throw get_error ("expected boolean expression");
-			}
-		}
-		return optype;
-	}
-
-	private PropertyType translate_conditional_or_expression (StringBuilder sql) throws Sparql.Error {
-		long begin = sql.len;
-		var optype = translate_conditional_and_expression (sql);
-		while (accept (SparqlTokenType.OP_OR)) {
-			if (optype != PropertyType.BOOLEAN) {
-				throw get_error ("expected boolean expression");
-			}
-			sql.insert (begin, "(");
-			sql.append (" OR ");
-			optype = translate_conditional_and_expression (sql);
-			sql.append (")");
-			if (optype != PropertyType.BOOLEAN) {
-				throw get_error ("expected boolean expression");
-			}
-		}
-		return optype;
-	}
-
-	internal PropertyType translate_expression (StringBuilder sql) throws Sparql.Error {
-		return translate_conditional_or_expression (sql);
-	}
-
-	private PropertyType translate_bracketted_expression (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.OPEN_PARENS);
-
-		if (current () == SparqlTokenType.SELECT) {
-			// scalar subquery
-
-			sql.append ("(");
-			var select_context = pattern.translate_select (sql, true, true);
-			sql.append (")");
-
-			expect (SparqlTokenType.CLOSE_PARENS);
-			return select_context.type;
-		}
-
-		var optype = translate_expression (sql);
-		expect (SparqlTokenType.CLOSE_PARENS);
-		return optype;
-	}
-
-	private PropertyType translate_aggregate_expression (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.OPEN_PARENS);
-		if (accept (SparqlTokenType.DISTINCT)) {
-			sql.append ("DISTINCT ");
-		}
-
-		bool is_var = (current () == SparqlTokenType.VAR);
-		var optype = translate_expression (sql);
-
-		if (is_var) {
-			var variable = context.get_variable (get_last_string ().substring (1));
-			if (variable.binding == null) {
-				throw get_error ("use of undefined variable `%s'".printf (variable.name));
-			}
-		}
-
-		expect (SparqlTokenType.CLOSE_PARENS);
-		return optype;
-	}
-
-	internal PropertyType translate_constraint (StringBuilder sql) throws Sparql.Error {
-		switch (current ()) {
-		case SparqlTokenType.STR:
-		case SparqlTokenType.LANG:
-		case SparqlTokenType.LANGMATCHES:
-		case SparqlTokenType.DATATYPE:
-		case SparqlTokenType.BOUND:
-		case SparqlTokenType.IF:
-		case SparqlTokenType.SAMETERM:
-		case SparqlTokenType.ISIRI:
-		case SparqlTokenType.ISURI:
-		case SparqlTokenType.ISBLANK:
-		case SparqlTokenType.ISLITERAL:
-		case SparqlTokenType.REGEX:
-		case SparqlTokenType.EXISTS:
-		case SparqlTokenType.NOT:
-			return translate_primary_expression (sql);
-		default:
-			return translate_bracketted_expression (sql);
-		}
-	}
-}
diff --git a/src/libtracker-data/tracker-sparql-pattern.vala b/src/libtracker-data/tracker-sparql-pattern.vala
deleted file mode 100644
index 59810da63..000000000
--- a/src/libtracker-data/tracker-sparql-pattern.vala
+++ /dev/null
@@ -1,1659 +0,0 @@
-/*
- * Copyright (C) 2008-2010, Nokia
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA  02110-1301, USA.
- */
-
-namespace Tracker.Sparql {
-	// Represents a variable used as a predicate
-	class PredicateVariable : Object {
-		public string? subject;
-		public string? object;
-		public bool return_graph;
-
-		public Class? domain;
-
-		Data.Manager manager;
-
-		public PredicateVariable (Data.Manager manager) {
-			this.manager = manager;
-		}
-
-		public string get_sql_query (Query query) throws Sparql.Error {
-			try {
-				var sql = new StringBuilder ();
-				var ontologies = manager.get_ontologies ();
-				var iface = manager.get_db_interface ();
-
-				if (subject != null) {
-					// single subject
-					var subject_id = Tracker.Data.query_resource_id (manager, iface, subject);
-
-					DBCursor cursor = null;
-					if (subject_id > 0) {
-						var stmt = iface.create_statement (DBStatementCacheType.SELECT,
-						                                   "SELECT (SELECT Uri FROM Resource WHERE ID = \"rdf:type\") " +
-						                                   "FROM \"rdfs:Resource_rdf:type\" WHERE ID = ?");
-						stmt.bind_int (0, subject_id);
-						cursor = stmt.start_cursor ();
-					}
-
-					bool first = true;
-					if (cursor != null) {
-						while (cursor.next ()) {
-							var domain = ontologies.get_class_by_uri (cursor.get_string (0));
-
-							foreach (Property prop in ontologies.get_properties ()) {
-								if (prop.domain == domain) {
-									if (first) {
-										first = false;
-									} else {
-										sql.append (" UNION ALL ");
-									}
-									sql.append_printf ("SELECT ID, (SELECT ID FROM Resource WHERE Uri = '%s') AS \"predicate\", ", prop.uri);
-
-									Expression.append_expression_as_string (sql, "\"%s\"".printf (prop.name), prop.data_type);
-
-									sql.append (" AS \"object\"");
-									if (return_graph) {
-										sql.append_printf (", \"%s:graph\" AS \"graph\"", prop.name);
-									}
-									sql.append_printf (" FROM \"%s\"", prop.table_name);
-
-									sql.append (" WHERE ID = ?");
-
-									var binding = new LiteralBinding ();
-									binding.literal = subject_id.to_string ();
-									binding.data_type = PropertyType.INTEGER;
-									query.bindings.append (binding);
-								}
-							}
-						}
-					}
-
-					if (first) {
-						/* no match */
-						sql.append ("SELECT NULL AS ID, NULL AS \"predicate\", NULL AS \"object\", NULL AS \"graph\"");
-					}
-				} else if (object != null) {
-					// single object
-					var object_id = Data.query_resource_id (manager, iface, object);
-
-					var stmt = iface.create_statement (DBStatementCacheType.SELECT,
-					                                   "SELECT (SELECT Uri FROM Resource WHERE ID = \"rdf:type\") " +
-					                                   "FROM \"rdfs:Resource_rdf:type\" WHERE ID = ?");
-					stmt.bind_int (0, object_id);
-					var cursor = stmt.start_cursor ();
-
-					bool first = true;
-					if (cursor != null) {
-						while (cursor.next ()) {
-							var range = ontologies.get_class_by_uri (cursor.get_string (0));
-
-							foreach (Property prop in ontologies.get_properties ()) {
-								if (prop.range == range) {
-									if (first) {
-										first = false;
-									} else {
-										sql.append (" UNION ALL ");
-									}
-									sql.append_printf ("SELECT ID, (SELECT ID FROM Resource WHERE Uri = '%s') AS \"predicate\", ", prop.uri);
-
-									Expression.append_expression_as_string (sql, "\"%s\"".printf (prop.name), prop.data_type);
-
-									sql.append (" AS \"object\"");
-									if (return_graph) {
-										sql.append_printf (", \"%s:graph\" AS \"graph\"", prop.name);
-									}
-									sql.append_printf (" FROM \"%s\"", prop.table_name);
-								}
-							}
-						}
-					}
-
-					if (first) {
-						/* no match */
-						sql.append ("SELECT NULL AS ID, NULL AS \"predicate\", NULL AS \"object\", NULL AS \"graph\"");
-					}
-				} else if (domain != null) {
-					// any subject, predicates limited to a specific domain
-					bool first = true;
-					foreach (Property prop in ontologies.get_properties ()) {
-						if (prop.domain == domain) {
-							if (first) {
-								first = false;
-							} else {
-								sql.append (" UNION ALL ");
-							}
-							sql.append_printf ("SELECT ID, (SELECT ID FROM Resource WHERE Uri = '%s') AS \"predicate\", ", prop.uri);
-
-							Expression.append_expression_as_string (sql, "\"%s\"".printf (prop.name), prop.data_type);
-
-							sql.append (" AS \"object\"");
-							if (return_graph) {
-								sql.append_printf (", \"%s:graph\" AS \"graph\"", prop.name);
-							}
-							sql.append_printf (" FROM \"%s\"", prop.table_name);
-						}
-					}
-				} else {
-					// UNION over all properties would exceed SQLite limits
-					throw query.get_internal_error ("Unrestricted predicate variables not supported");
-				}
-				return sql.str;
-			} catch (GLib.Error e) {
-				throw new Sparql.Error.INTERNAL (e.message);
-			}
-		}
-	}
-}
-
-class Tracker.Sparql.Pattern : Object {
-	weak Query query;
-	weak Expression expression;
-
-	int counter;
-
-	int next_table_index;
-
-	internal string current_graph;
-	bool current_graph_is_var;
-	string current_subject;
-	bool current_subject_is_var;
-	string current_predicate;
-	bool current_predicate_is_var;
-	public Variable? fts_subject;
-	public string[] fts_variables;
-	internal StringBuilder? match_str;
-	public bool queries_fts_data = false;
-
-	Data.Manager manager;
-
-	public Pattern (Query query) {
-		this.query = query;
-		this.manager = query.manager;
-		this.expression = query.expression;
-	}
-
-	Context context {
-		get { return query.context; }
-		set { query.context = value; }
-	}
-
-	private inline bool next () throws Sparql.Error {
-		return query.next ();
-	}
-
-	private inline SparqlTokenType current () {
-		return query.current ();
-	}
-
-	private inline bool accept (SparqlTokenType type) throws Sparql.Error {
-		return query.accept (type);
-	}
-
-	private inline void optional (SparqlTokenType type) throws Sparql.Error {
-		query.optional (type);
-	}
-
-	private Sparql.Error get_error (string msg) {
-		return query.get_error (msg);
-	}
-
-	private bool expect (SparqlTokenType type) throws Sparql.Error {
-		return query.expect (type);
-	}
-
-	private SourceLocation get_location () {
-		return query.get_location ();
-	}
-
-	private void set_location (SourceLocation location) {
-		query.set_location (location);
-	}
-
-	private string get_last_string (int strip = 0) {
-		return query.get_last_string (strip);
-	}
-
-	class TripleContext : Context {
-		// SQL tables
-		public List<DataTable> tables;
-		public HashTable<string,DataTable> table_map;
-		// SPARQL literals
-		public List<LiteralBinding> bindings;
-		// SPARQL variables
-		public List<Variable> variables;
-		public HashTable<Variable,VariableBindingList> var_bindings;
-
-		public TripleContext (Query query, Context parent_context) {
-			base (query, parent_context);
-
-			tables = new List<DataTable> ();
-			table_map = new HashTable<string,DataTable>.full (str_hash, str_equal, g_free, g_object_unref);
-
-			variables = new List<Variable> ();
-			var_bindings = new HashTable<Variable,VariableBindingList>.full (Variable.hash, Variable.equal, g_object_unref, g_object_unref);
-
-			bindings = new List<LiteralBinding> ();
-		}
-	}
-
-	TripleContext? triple_context;
-
-	internal SelectContext translate_select (StringBuilder sql, bool subquery = false, bool scalar_subquery = false) throws Sparql.Error {
-		SelectContext result;
-
-		if (scalar_subquery) {
-			result = new SelectContext.subquery (query, context);
-		} else {
-			result = new SelectContext (query, context);
-		}
-		context = result;
-		var type = PropertyType.UNKNOWN;
-
-		var pattern_sql = new StringBuilder ();
-		var old_bindings = (owned) query.bindings;
-
-		sql.append ("SELECT ");
-
-		expect (SparqlTokenType.SELECT);
-
-		if (accept (SparqlTokenType.DISTINCT)) {
-			sql.append ("DISTINCT ");
-		} else if (accept (SparqlTokenType.REDUCED)) {
-		}
-
-		// skip select variables (processed later)
-		var select_variables_location = get_location ();
-		expression.skip_select_variables ();
-
-		if (accept (SparqlTokenType.FROM)) {
-			accept (SparqlTokenType.NAMED);
-			expect (SparqlTokenType.IRI_REF);
-		}
-
-		optional (SparqlTokenType.WHERE);
-
-		var pattern = translate_group_graph_pattern (pattern_sql);
-		foreach (var key in pattern.var_set.get_keys ()) {
-			context.var_set.insert (key, VariableState.BOUND);
-		}
-
-		// process select variables
-		var after_where = get_location ();
-		set_location (select_variables_location);
-
-		// report use of undefined variables
-		foreach (var variable in context.var_set.get_keys ()) {
-			if (variable.binding == null) {
-				throw get_error ("use of undefined variable `%s'".printf (variable.name));
-			}
-		}
-
-		var where_bindings = (owned) query.bindings;
-		query.bindings = (owned) old_bindings;
-
-		bool first = true;
-		if (accept (SparqlTokenType.STAR)) {
-			foreach (var variable in context.var_set.get_keys ()) {
-				if (!first) {
-					sql.append (", ");
-				} else {
-					first = false;
-				}
-				if (subquery) {
-					// don't convert to string in subqueries
-					sql.append (variable.sql_expression);
-				} else {
-					Expression.append_expression_as_string (sql, variable.sql_expression, variable.binding.data_type);
-					sql.append_printf (" AS \"%s\"", variable.name);
-				}
-				result.types += variable.binding.data_type;
-				result.variable_names += variable.name;
-			}
-		} else {
-			for (int i = 0; ; i++) {
-				first = false;
-
-				if (i > 0) {
-					sql.append (", ");
-				}
-
-				type = expression.translate_select_expression (sql, subquery, i);
-				result.types += type;
-
-				switch (current ()) {
-				case SparqlTokenType.FROM:
-				case SparqlTokenType.WHERE:
-				case SparqlTokenType.OPEN_BRACE:
-				case SparqlTokenType.GROUP:
-				case SparqlTokenType.ORDER:
-				case SparqlTokenType.LIMIT:
-				case SparqlTokenType.OFFSET:
-				case SparqlTokenType.EOF:
-					break;
-				default:
-					continue;
-				}
-				break;
-			}
-		}
-
-		if (queries_fts_data && fts_subject != null) {
-			// Ensure there's a rowid to match on in FTS queries
-			if (!first) {
-				sql.append (", ");
-			} else {
-				first = false;
-			}
-
-			sql.append ("%s AS rowid ".printf (fts_subject.sql_expression));
-		}
-
-		// literals in select expressions need to be bound before literals in the where clause
-		foreach (var binding in where_bindings) {
-			query.bindings.append (binding);
-		}
-
-		if (first) {
-			sql.append ("NULL");
-		}
-
-		// select from results of WHERE clause
-		sql.append (" FROM (");
-		sql.append (pattern_sql.str);
-		sql.append (")");
-
-		set_location (after_where);
-
-		if (accept (SparqlTokenType.GROUP)) {
-			expect (SparqlTokenType.BY);
-			sql.append (" GROUP BY ");
-			bool first_group = true;
-			do {
-				if (first_group) {
-					first_group = false;
-				} else {
-					sql.append (", ");
-				}
-				expression.translate_expression (sql);
-			} while (current () != SparqlTokenType.HAVING && current () != SparqlTokenType.ORDER && current () != SparqlTokenType.LIMIT && current () != SparqlTokenType.OFFSET && current () != SparqlTokenType.CLOSE_BRACE && current () != SparqlTokenType.CLOSE_PARENS && current () != SparqlTokenType.EOF);
-
-			if (accept (SparqlTokenType.HAVING)) {
-				sql.append (" HAVING ");
-				expression.translate_constraint (sql);
-			}
-		}
-
-		if (accept (SparqlTokenType.ORDER)) {
-			expect (SparqlTokenType.BY);
-			sql.append (" ORDER BY ");
-			bool first_order = true;
-			do {
-				if (first_order) {
-					first_order = false;
-				} else {
-					sql.append (", ");
-				}
-				expression.translate_order_condition (sql);
-			} while (current () != SparqlTokenType.LIMIT && current () != SparqlTokenType.OFFSET && current () != SparqlTokenType.CLOSE_BRACE && current () != SparqlTokenType.CLOSE_PARENS && current () != SparqlTokenType.EOF);
-		}
-
-		int limit = -1;
-		int offset = -1;
-
-		if (accept (SparqlTokenType.LIMIT)) {
-			expect (SparqlTokenType.INTEGER);
-			limit = int.parse (get_last_string ());
-			if (accept (SparqlTokenType.OFFSET)) {
-				expect (SparqlTokenType.INTEGER);
-				offset = int.parse (get_last_string ());
-			}
-		} else if (accept (SparqlTokenType.OFFSET)) {
-			expect (SparqlTokenType.INTEGER);
-			offset = int.parse (get_last_string ());
-			if (accept (SparqlTokenType.LIMIT)) {
-				expect (SparqlTokenType.INTEGER);
-				limit = int.parse (get_last_string ());
-			}
-		}
-
-		// LIMIT and OFFSET
-		if (limit >= 0) {
-			sql.append (" LIMIT ?");
-
-			var binding = new LiteralBinding ();
-			binding.literal = limit.to_string ();
-			binding.data_type = PropertyType.INTEGER;
-			query.bindings.append (binding);
-
-			if (offset >= 0) {
-				sql.append (" OFFSET ?");
-
-				binding = new LiteralBinding ();
-				binding.literal = offset.to_string ();
-				binding.data_type = PropertyType.INTEGER;
-				query.bindings.append (binding);
-			}
-		} else if (offset >= 0) {
-			sql.append (" LIMIT -1 OFFSET ?");
-
-			var binding = new LiteralBinding ();
-			binding.literal = offset.to_string ();
-			binding.data_type = PropertyType.INTEGER;
-			query.bindings.append (binding);
-		}
-
-		if (queries_fts_data && match_str != null && fts_subject != null) {
-			var str = new StringBuilder ("SELECT ");
-			first = true;
-
-			foreach (var fts_var in fts_variables) {
-				if (!first) {
-					str.append (", ");
-				} else {
-					first = false;
-				}
-
-				str.append (fts_var);
-			}
-
-			str.append (" FROM fts5 JOIN (");
-			sql.prepend (str.str);
-			sql.append_printf (") AS ranks ON fts5.rowid=rowid WHERE fts5 %s".printf (match_str.str));
-		}
-
-		context = context.parent_context;
-
-		result.type = type;
-		match_str = null;
-		fts_subject = null;
-
-		return result;
-	}
-
-	internal void translate_exists (StringBuilder sql) throws Sparql.Error {
-		bool not = accept (SparqlTokenType.NOT);
-		expect (SparqlTokenType.EXISTS);
-
-		SelectContext result;
-		result = new SelectContext.subquery (query, context);
-		context = result;
-
-		if (not) {
-			// NOT EXISTS
-			sql.append ("NOT EXISTS (");
-		} else {
-			// EXISTS
-			sql.append ("EXISTS (");
-		}
-
-		var pattern = translate_group_graph_pattern (sql);
-		foreach (var key in pattern.var_set.get_keys ()) {
-			context.var_set.insert (key, VariableState.BOUND);
-		}
-
-		// report use of undefined variables
-		foreach (var variable in context.var_set.get_keys ()) {
-			if (variable.binding == null) {
-				throw get_error ("use of undefined variable `%s'".printf (variable.name));
-			}
-		}
-
-		sql.append (")");
-
-		context = context.parent_context;
-	}
-
-	internal string parse_var_or_term (StringBuilder? sql, out bool is_var) throws Sparql.Error {
-		string result = "";
-		is_var = false;
-		if (current () == SparqlTokenType.VAR) {
-			is_var = true;
-			next ();
-			result = get_last_string ().substring (1);
-		} else if (current () == SparqlTokenType.IRI_REF) {
-			next ();
-			result = get_last_string (1);
-		} else if (current () == SparqlTokenType.PN_PREFIX) {
-			// prefixed name with namespace foo:bar
-			next ();
-			string ns = get_last_string ();
-			expect (SparqlTokenType.COLON);
-			result = query.resolve_prefixed_name (ns, get_last_string ().substring (1));
-		} else if (current () == SparqlTokenType.COLON) {
-			// prefixed name without namespace :bar
-			next ();
-			result = query.resolve_prefixed_name ("", get_last_string ().substring (1));
-		} else if (accept (SparqlTokenType.BLANK_NODE)) {
-			// _:foo
-			expect (SparqlTokenType.COLON);
-			result = query.generate_bnodeid (get_last_string ().substring (1));
-		} else if (current () == SparqlTokenType.STRING_LITERAL1) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL2) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL_LONG1) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL_LONG2) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.INTEGER) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.DECIMAL) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.DOUBLE) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.TRUE) {
-			next ();
-			result = "true";
-		} else if (current () == SparqlTokenType.FALSE) {
-			next ();
-			result = "false";
-		} else if (current () == SparqlTokenType.OPEN_BRACKET) {
-			next ();
-
-			result = query.generate_bnodeid (null);
-
-			string old_subject = current_subject;
-			bool old_subject_is_var = current_subject_is_var;
-
-			current_subject = result;
-			current_subject_is_var = true;
-			parse_property_list_not_empty (sql);
-			expect (SparqlTokenType.CLOSE_BRACKET);
-
-			current_subject = old_subject;
-			current_subject_is_var = old_subject_is_var;
-
-			is_var = true;
-		} else {
-			throw get_error ("expected variable or term");
-		}
-		return result;
-	}
-
-	private void parse_object_list (StringBuilder sql, bool in_simple_optional = false) throws Sparql.Error {
-		while (true) {
-			parse_object (sql, in_simple_optional);
-			if (accept (SparqlTokenType.COMMA)) {
-				continue;
-			}
-			break;
-		}
-	}
-
-	private void parse_property_list_not_empty (StringBuilder sql, bool in_simple_optional = false) throws Sparql.Error {
-		while (true) {
-			var old_predicate = current_predicate;
-			var old_predicate_is_var = current_predicate_is_var;
-
-			current_predicate = null;
-			current_predicate_is_var = false;
-			if (current () == SparqlTokenType.VAR) {
-				current_predicate_is_var = true;
-				next ();
-				current_predicate = get_last_string ().substring (1);
-			} else if (current () == SparqlTokenType.IRI_REF) {
-				next ();
-				current_predicate = get_last_string (1);
-			} else if (current () == SparqlTokenType.PN_PREFIX) {
-				next ();
-				string ns = get_last_string ();
-				expect (SparqlTokenType.COLON);
-				current_predicate = query.resolve_prefixed_name (ns, get_last_string ().substring (1));
-			} else if (current () == SparqlTokenType.COLON) {
-				next ();
-				current_predicate = query.resolve_prefixed_name ("", get_last_string ().substring (1));
-			} else if (current () == SparqlTokenType.A) {
-				next ();
-				current_predicate = "http://www.w3.org/1999/02/22-rdf-syntax-ns#type";
-			} else {
-				throw get_error ("expected non-empty property list");
-			}
-			parse_object_list (sql, in_simple_optional);
-
-			current_predicate = old_predicate;
-			current_predicate_is_var = old_predicate_is_var;
-
-			if (accept (SparqlTokenType.SEMICOLON)) {
-				if (current () == SparqlTokenType.DOT) {
-					// semicolon before dot is allowed in both, SPARQL and Turtle
-					break;
-				}
-				continue;
-			}
-			break;
-		}
-	}
-
-	private void translate_filter (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.FILTER);
-		expression.translate_constraint (sql);
-	}
-
-	private void skip_filter () throws Sparql.Error {
-		expect (SparqlTokenType.FILTER);
-
-		switch (current ()) {
-		case SparqlTokenType.STR:
-		case SparqlTokenType.LANG:
-		case SparqlTokenType.LANGMATCHES:
-		case SparqlTokenType.DATATYPE:
-		case SparqlTokenType.BOUND:
-		case SparqlTokenType.SAMETERM:
-		case SparqlTokenType.ISIRI:
-		case SparqlTokenType.ISURI:
-		case SparqlTokenType.ISBLANK:
-		case SparqlTokenType.ISLITERAL:
-		case SparqlTokenType.REGEX:
-			next ();
-			break;
-		default:
-			break;
-		}
-
-		expect (SparqlTokenType.OPEN_PARENS);
-		int n_parens = 1;
-		while (n_parens > 0) {
-			if (accept (SparqlTokenType.OPEN_PARENS)) {
-				n_parens++;
-			} else if (accept (SparqlTokenType.CLOSE_PARENS)) {
-				n_parens--;
-			} else if (current () == SparqlTokenType.EOF) {
-				throw get_error ("unexpected end of query, expected )");
-			} else {
-				// ignore everything else
-				next ();
-			}
-		}
-	}
-
-	private void start_triples_block (StringBuilder sql) throws Sparql.Error {
-		context = triple_context = new TripleContext (query, context);
-
-		sql.append ("SELECT ");
-	}
-
-	private void end_triples_block (StringBuilder sql, ref bool first_where, bool in_group_graph_pattern) throws Sparql.Error {
-		// remove last comma and space
-		sql.truncate (sql.len - 2);
-
-		sql.append (" FROM ");
-		bool first = true;
-		foreach (DataTable table in triple_context.tables) {
-			if (!first) {
-				sql.append (", ");
-			} else {
-				first = false;
-			}
-			if (table.sql_db_tablename != null) {
-				sql.append_printf ("\"%s\"", table.sql_db_tablename);
-			} else {
-				sql.append_printf ("(%s)", table.predicate_variable.get_sql_query (query));
-			}
-			sql.append_printf (" AS \"%s\"", table.sql_query_tablename);
-		}
-
-		foreach (var variable in triple_context.variables) {
-			bool maybe_null = true;
-			bool in_simple_optional = false;
-			PropertyType last_type = PropertyType.UNKNOWN;
-			string last_name = null;
-			foreach (VariableBinding binding in triple_context.var_bindings.lookup (variable).list) {
-				string name;
-				if (binding.table != null) {
-					name = binding.sql_expression;
-				} else {
-					// simple optional with inverse functional property
-					// always first in loop as variable is required to be unbound
-					name = variable.sql_expression;
-				}
-				var type = binding.data_type;
-				if (last_name != null) {
-					if (!first_where) {
-						sql.append (" AND ");
-					} else {
-						sql.append (" WHERE ");
-						first_where = false;
-					}
-
-					if (last_type == PropertyType.STRING && type == PropertyType.RESOURCE) {
-						sql.append_printf ("(SELECT ID FROM Resource WHERE Uri = %s)", last_name);
-					} else {
-						sql.append (last_name);
-					}
-
-					sql.append (" = ");
-
-					if (last_type == PropertyType.RESOURCE && type == PropertyType.STRING) {
-						sql.append_printf ("(SELECT ID FROM Resource WHERE Uri = %s)", name);
-					} else {
-						sql.append (name);
-					}
-				}
-				last_name = name;
-				last_type = type;
-				if (!binding.maybe_null) {
-					maybe_null = false;
-				}
-				in_simple_optional = binding.in_simple_optional;
-			}
-
-			if (maybe_null && !in_simple_optional) {
-				// ensure that variable is bound in case it could return NULL in SQL
-				// assuming SPARQL variable is not optional
-				if (!first_where) {
-					sql.append (" AND ");
-				} else {
-					sql.append (" WHERE ");
-					first_where = false;
-				}
-				sql.append_printf ("%s IS NOT NULL", variable.sql_expression);
-			}
-		}
-		foreach (LiteralBinding binding in triple_context.bindings) {
-			if (!first_where) {
-				sql.append (" AND ");
-			} else {
-				sql.append (" WHERE ");
-				first_where = false;
-			}
-			sql.append (binding.sql_expression);
-			if (binding.is_fts_match) {
-				// parameters do not work with fts MATCH
-				string escaped_literal = string.joinv ("''", binding.literal.split ("'"));
-				sql.append_printf (" MATCH '%s'", escaped_literal);
-
-				if (match_str == null) {
-				        match_str = new StringBuilder ();
-					match_str.append_printf (" MATCH '%s'", escaped_literal);
-				}
-			} else {
-				sql.append (" = ");
-				if (binding.data_type == PropertyType.RESOURCE) {
-					sql.append ("(SELECT ID FROM Resource WHERE Uri = ?)");
-				} else {
-					sql.append ("?");
-				}
-				query.bindings.append (binding);
-			}
-		}
-
-		if (in_group_graph_pattern) {
-			sql.append (")");
-		}
-
-		foreach (var v in context.var_set.get_keys ()) {
-			context.parent_context.var_set.insert (v, VariableState.BOUND);
-		}
-
-		triple_context = null;
-		context = context.parent_context;
-	}
-
-	private void parse_triples (StringBuilder sql, long group_graph_pattern_start, ref bool in_triples_block, ref bool first_where, ref bool in_group_graph_pattern, bool found_simple_optional) throws Sparql.Error {
-		while (true) {
-			if (current () != SparqlTokenType.VAR &&
-			    current () != SparqlTokenType.IRI_REF &&
-			    current () != SparqlTokenType.PN_PREFIX &&
-			    current () != SparqlTokenType.COLON &&
-			    current () != SparqlTokenType.OPEN_BRACKET) {
-				break;
-			}
-			if (in_triples_block && !in_group_graph_pattern && found_simple_optional) {
-				// if there is a regular triple pattern after a simple optional
-				// we need to use a separate triple block to avoid possible conflicts
-				// due to not using a JOIN for the simple optional
-				end_triples_block (sql, ref first_where, in_group_graph_pattern);
-				in_triples_block = false;
-				in_group_graph_pattern = true;
-			}
-			if (!in_triples_block) {
-				if (in_group_graph_pattern) {
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					sql.append (") NATURAL INNER JOIN (");
-				}
-				in_triples_block = true;
-				first_where = true;
-				start_triples_block (sql);
-			}
-
-			current_subject = parse_var_or_term (sql, out current_subject_is_var);
-			parse_property_list_not_empty (sql);
-
-			if (!accept (SparqlTokenType.DOT)) {
-				break;
-			}
-		}
-	}
-
-	private bool is_subclass (Class class1, Class class2) {
-		if (class1 == class2) {
-			return true;
-		}
-		foreach (var superclass in class1.get_super_classes ()) {
-			if (is_subclass (superclass, class2)) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	private bool is_simple_optional () {
-		var optional_start = get_location ();
-		try {
-			// check that we have { ?v foo:bar ?o }
-			// where ?v is an already BOUND variable
-			//       foo:bar is a single-valued property
-			//               that is known to be in domain of ?v
-			//       ?o has not been used before
-			// or
-			// where ?v has not been used before
-			//       foo:bar is an inverse functional property
-			//       ?o is an already ?BOUND variable
-
-			expect (SparqlTokenType.OPEN_BRACE);
-
-			// check subject
-			if (!accept (SparqlTokenType.VAR)) {
-				return false;
-			}
-			var left_variable = context.get_variable (get_last_string ().substring (1));
-			var left_variable_state = context.var_set.lookup (left_variable);
-
-			// check predicate
-			string predicate;
-			if (accept (SparqlTokenType.IRI_REF)) {
-				predicate = get_last_string (1);
-			} else if (accept (SparqlTokenType.PN_PREFIX)) {
-				string ns = get_last_string ();
-				expect (SparqlTokenType.COLON);
-				predicate = query.resolve_prefixed_name (ns, get_last_string ().substring (1));
-			} else if (accept (SparqlTokenType.COLON)) {
-				predicate = query.resolve_prefixed_name ("", get_last_string ().substring (1));
-			} else {
-				return false;
-			}
-			var ontologies = manager.get_ontologies ();
-			var prop = ontologies.get_property_by_uri (predicate);
-			if (prop == null) {
-				return false;
-			}
-
-			// check object
-			if (!accept (SparqlTokenType.VAR)) {
-				return false;
-			}
-			var right_variable = context.get_variable (get_last_string ().substring (1));
-			var right_variable_state = context.var_set.lookup (right_variable);
-
-			optional (SparqlTokenType.DOT);
-
-			// check it is only one triple pattern
-			if (!accept (SparqlTokenType.CLOSE_BRACE)) {
-				return false;
-			}
-
-			if (left_variable_state == VariableState.BOUND && !prop.multiple_values && right_variable_state == 0) {
-				bool in_domain = false;
-				foreach (VariableBinding binding in triple_context.var_bindings.lookup (left_variable).list) {
-					if (binding.type != null && is_subclass (binding.type, prop.domain)) {
-						in_domain = true;
-						break;
-					}
-				}
-
-				if (in_domain) {
-					// first valid case described in above comment
-					return true;
-				}
-			} else if (left_variable_state == 0 && prop.is_inverse_functional_property && right_variable_state == VariableState.BOUND) {
-				// second valid case described in above comment
-				return true;
-			}
-
-			// no match
-			return false;
-		} catch (Sparql.Error e) {
-			return false;
-		} finally {
-			// in any case, go back to the start of the optional
-			set_location (optional_start);
-		}
-	}
-
-	internal Context translate_group_graph_pattern (StringBuilder sql) throws Sparql.Error {
-		expect (SparqlTokenType.OPEN_BRACE);
-
-		if (current () == SparqlTokenType.SELECT) {
-			var result = translate_select (sql, true);
-			context = result;
-
-			// only export selected variables
-			context.var_set = context.select_var_set;
-			context.select_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-
-			expect (SparqlTokenType.CLOSE_BRACE);
-
-			context = context.parent_context;
-			return result;
-		}
-
-		var result = new Context (query, context);
-		context = result;
-
-		SourceLocation[] filters = { };
-
-		bool in_triples_block = false;
-		bool in_group_graph_pattern = false;
-		bool first_where = true;
-		bool found_simple_optional = false;
-		long group_graph_pattern_start = sql.len;
-
-		// optional TriplesBlock
-		parse_triples (sql, group_graph_pattern_start, ref in_triples_block, ref first_where, ref in_group_graph_pattern, found_simple_optional);
-
-		while (true) {
-			// check whether we have GraphPatternNotTriples | Filter
-			if (accept (SparqlTokenType.OPTIONAL)) {
-				if (!in_group_graph_pattern && is_simple_optional ()) {
-					// perform join-less optional (like non-optional except for the IS NOT NULL check)
-					found_simple_optional = true;
-					expect (SparqlTokenType.OPEN_BRACE);
-
-					current_subject = parse_var_or_term (sql, out current_subject_is_var);
-					parse_property_list_not_empty (sql, true);
-
-					accept (SparqlTokenType.DOT);
-					expect (SparqlTokenType.CLOSE_BRACE);
-				} else {
-					if (!in_triples_block && !in_group_graph_pattern) {
-						// expand { OPTIONAL { ... } } into { { } OPTIONAL { ... } }
-						// empty graph pattern => return one result without bound variables
-						sql.append ("SELECT 1");
-					} else if (in_triples_block) {
-						end_triples_block (sql, ref first_where, in_group_graph_pattern);
-						in_triples_block = false;
-					}
-					if (!in_group_graph_pattern) {
-						in_group_graph_pattern = true;
-					}
-
-					var select = new StringBuilder ("SELECT ");
-
-					int left_index = ++next_table_index;
-					int right_index = ++next_table_index;
-
-					sql.append_printf (") AS t%d_g LEFT JOIN (", left_index);
-
-					context = translate_group_graph_pattern (sql);
-
-					sql.append_printf (") AS t%d_g", right_index);
-
-					bool first = true;
-					bool first_common = true;
-					foreach (var v in context.var_set.get_keys ()) {
-						if (first) {
-							first = false;
-						} else {
-							select.append (", ");
-						}
-
-						var old_state = context.parent_context.var_set.lookup (v);
-						if (old_state == 0) {
-							// first used in optional part
-							context.parent_context.var_set.insert (v, VariableState.OPTIONAL);
-							select.append_printf ("t%d_g.%s", right_index, v.sql_expression);
-
-							if (v.binding.data_type == PropertyType.DATETIME) {
-								select.append_printf (", t%d_g.%s", right_index, v.get_extra_sql_expression ("localDate"));
-								select.append_printf (", t%d_g.%s", right_index, v.get_extra_sql_expression ("localTime"));
-							}
-						} else {
-							if (first_common) {
-								sql.append (" ON ");
-								first_common = false;
-							} else {
-								sql.append (" AND ");
-							}
-
-							if (old_state == VariableState.BOUND) {
-								// variable definitely bound in non-optional part
-								sql.append_printf ("t%d_g.%s = t%d_g.%s", left_index, v.sql_expression, right_index, v.sql_expression);
-								select.append_printf ("t%d_g.%s", left_index, v.sql_expression);
-
-								if (v.binding.data_type == PropertyType.DATETIME) {
-									select.append_printf (", t%d_g.%s", left_index, v.get_extra_sql_expression ("localDate"));
-									select.append_printf (", t%d_g.%s", left_index, v.get_extra_sql_expression ("localTime"));
-								}
-							} else if (old_state == VariableState.OPTIONAL) {
-								// variable maybe bound in non-optional part
-								sql.append_printf ("(t%d_g.%s IS NULL OR t%d_g.%s = t%d_g.%s)", left_index, v.sql_expression, left_index, v.sql_expression, right_index, v.sql_expression);
-								select.append_printf ("COALESCE (t%d_g.%s, t%d_g.%s) AS %s", left_index, v.sql_expression, right_index, v.sql_expression, v.sql_expression);
-
-								if (v.binding.data_type == PropertyType.DATETIME) {
-									select.append_printf (", COALESCE (t%d_g.%s, t%d_g.%s) AS %s", left_index, v.get_extra_sql_expression ("localDate"), right_index, v.get_extra_sql_expression ("localDate"), v.get_extra_sql_expression ("localDate"));
-									select.append_printf (", COALESCE (t%d_g.%s, t%d_g.%s) AS %s", left_index, v.get_extra_sql_expression ("localTime"), right_index, v.get_extra_sql_expression ("localTime"), v.get_extra_sql_expression ("localTime"));
-								}
-							}
-						}
-					}
-					foreach (var v in context.parent_context.var_set.get_keys ()) {
-						if (context.var_set.lookup (v) == 0) {
-							// only used in non-optional part
-							if (first) {
-								first = false;
-							} else {
-								select.append (", ");
-							}
-
-							select.append_printf ("t%d_g.%s", left_index, v.sql_expression);
-
-							if (v.binding.data_type == PropertyType.DATETIME) {
-								select.append_printf (", t%d_g.%s", left_index, v.get_extra_sql_expression ("localDate"));
-								select.append_printf (", t%d_g.%s", left_index, v.get_extra_sql_expression ("localTime"));
-							}
-						}
-					}
-					if (first) {
-						// no variables used at all
-						select.append ("1");
-					}
-
-					context = context.parent_context;
-
-					select.append (" FROM (");
-					sql.insert (group_graph_pattern_start, select.str);
-
-					// surround with SELECT * FROM (...) to avoid ambiguous column names
-					// in SQL generated for FILTER (triggered by using table aliases for join sources)
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					sql.append (")");
-				}
-			} else if (accept (SparqlTokenType.GRAPH)) {
-				var old_graph = current_graph;
-				var old_graph_is_var = current_graph_is_var;
-				current_graph = parse_var_or_term (sql, out current_graph_is_var);
-
-				if (!in_triples_block && !in_group_graph_pattern) {
-					in_group_graph_pattern = true;
-
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					translate_group_or_union_graph_pattern (sql);
-					sql.append (")");
-				} else {
-					if (in_triples_block) {
-						end_triples_block (sql, ref first_where, in_group_graph_pattern);
-						in_triples_block = false;
-					}
-					if (!in_group_graph_pattern) {
-						in_group_graph_pattern = true;
-					}
-
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					sql.append (") NATURAL INNER JOIN (");
-					translate_group_or_union_graph_pattern (sql);
-					sql.append (")");
-				}
-
-				current_graph = old_graph;
-				current_graph_is_var = old_graph_is_var;
-			} else if (accept (SparqlTokenType.BIND)) {
-				var binding = new VariableBinding ();
-				var bind_sql = new StringBuilder ();
-
-				expect (SparqlTokenType.OPEN_PARENS);
-
-				// We only need the binding sql expression when
-				// we are not in a group graph pattern, both
-				// cases are handled differently below.
-				context.need_binding_expression = !in_group_graph_pattern;
-				expression.translate_expression (bind_sql);
-				context.need_binding_expression = false;
-				binding.sql_expression = bind_sql.str;
-
-				expect (SparqlTokenType.AS);
-				expect (SparqlTokenType.VAR);
-
-				var as_var = context.get_variable (get_last_string ().substring (1));
-
-				if (as_var.binding != null) {
-					throw query.get_internal_error ("Expected undefined variable in BIND alias");
-				}
-
-				binding.variable = as_var;
-
-				if (in_group_graph_pattern) {
-					// Surround the entire group graph pattern with
-					// SELECT $binding , * FROM (...)
-					var binding_sql = new StringBuilder ("SELECT ");
-					add_variable_binding (binding_sql, binding, VariableState.BOUND);
-					binding_sql.append (" * FROM (");
-					sql.insert (group_graph_pattern_start, binding_sql.str);
-					sql.append (")");
-				} else {
-					// This is the "simple" case, where we are
-					// still constructing the SELECT ... part,
-					// just add the binding sql in this case.
-					add_variable_binding (sql, binding, VariableState.BOUND);
-				}
-
-				expect (SparqlTokenType.CLOSE_PARENS);
-			} else if (current () == SparqlTokenType.OPEN_BRACE) {
-				if (!in_triples_block && !in_group_graph_pattern) {
-					in_group_graph_pattern = true;
-
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					translate_group_or_union_graph_pattern (sql);
-					sql.append (")");
-				} else {
-					if (in_triples_block) {
-						end_triples_block (sql, ref first_where, in_group_graph_pattern);
-						in_triples_block = false;
-					}
-					if (!in_group_graph_pattern) {
-						in_group_graph_pattern = true;
-					}
-
-					sql.insert (group_graph_pattern_start, "SELECT * FROM (");
-					sql.append (") NATURAL INNER JOIN (");
-					translate_group_or_union_graph_pattern (sql);
-					sql.append (")");
-				}
-			} else if (current () == SparqlTokenType.FILTER) {
-				filters += get_location ();
-				skip_filter ();
-			} else {
-				break;
-			}
-
-			optional (SparqlTokenType.DOT);
-
-			// optional TriplesBlock
-			parse_triples (sql, group_graph_pattern_start, ref in_triples_block, ref first_where, ref in_group_graph_pattern, found_simple_optional);
-		}
-
-		expect (SparqlTokenType.CLOSE_BRACE);
-
-		if (!in_triples_block && !in_group_graph_pattern) {
-			// empty graph pattern => return one result without bound variables
-			sql.append ("SELECT 1");
-		} else if (in_triples_block) {
-			end_triples_block (sql, ref first_where, in_group_graph_pattern);
-			in_triples_block = false;
-		}
-
-		if (in_group_graph_pattern) {
-			first_where = true;
-		}
-
-		// handle filters last, they apply to the pattern as a whole
-		if (filters.length > 0) {
-			var end = get_location ();
-
-			foreach (var filter_location in filters) {
-				if (!first_where) {
-					sql.append (" AND ");
-				} else {
-					sql.append (" WHERE ");
-					first_where = false;
-				}
-
-				set_location (filter_location);
-				translate_filter (sql);
-			}
-
-			set_location (end);
-		}
-
-		context = context.parent_context;
-		return result;
-	}
-
-	private void translate_group_or_union_graph_pattern (StringBuilder sql) throws Sparql.Error {
-		Variable[] all_vars = { };
-		HashTable<Variable,int> all_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-
-		Context[] contexts = { };
-		long[] offsets = { };
-
-		do {
-			offsets += sql.len;
-			contexts += translate_group_graph_pattern (sql);
-		} while (accept (SparqlTokenType.UNION));
-
-		if (contexts.length > 1) {
-			// union graph pattern
-
-			// create union of all variables
-			foreach (var sub_context in contexts) {
-				foreach (var v in sub_context.var_set.get_keys ()) {
-					if (all_var_set.lookup (v) == 0) {
-						all_vars += v;
-						all_var_set.insert (v, VariableState.BOUND);
-						context.var_set.insert (v, VariableState.BOUND);
-					}
-				}
-			}
-
-			long extra_offset = 0;
-			for (int i = 0; i < contexts.length; i++) {
-				var projection = new StringBuilder ();
-				if (i > 0) {
-					projection.append (") UNION ALL ");
-				}
-				projection.append ("SELECT ");
-				foreach (var v in all_vars) {
-					if (contexts[i].var_set.lookup (v) == 0) {
-						// variable not used in this subgraph
-						// use NULL
-						projection.append ("NULL AS ");
-					}
-					projection.append_printf ("%s, ", v.sql_expression);
-				}
-				// delete last comma and space
-				projection.truncate (projection.len - 2);
-				projection.append (" FROM (");
-
-				sql.insert (offsets[i] + extra_offset, projection.str);
-				extra_offset += projection.len;
-			}
-			sql.append (")");
-		} else {
-			foreach (var key in contexts[0].var_set.get_keys ()) {
-				context.var_set.insert (key, VariableState.BOUND);
-			}
-		}
-	}
-
-	private VariableBindingList? get_variable_binding_list (Variable variable) {
-		VariableBindingList binding_list = null;
-		if (triple_context != null) {
-			binding_list = triple_context.var_bindings.lookup (variable);
-		}
-		if (binding_list == null && variable.binding != null) {
-			// might be in scalar subquery: check variables of outer queries
-			var current_context = context;
-			while (current_context != null) {
-				// only allow access to variables of immediate parent context of the subquery
-				// allowing access to other variables leads to invalid SQL or wrong results
-				if (current_context.scalar_subquery && current_context.parent_context.var_set.lookup (variable) != 0) {
-					// capture outer variable
-					var binding = new VariableBinding ();
-					binding.data_type = variable.binding.data_type;
-					binding.variable = context.get_variable (variable.name);
-					binding.type = variable.binding.type;
-					binding.sql_expression = variable.sql_expression;
-					binding_list = new VariableBindingList ();
-					if (triple_context != null) {
-						triple_context.variables.append (variable);
-						triple_context.var_bindings.insert (variable, binding_list);
-					}
-
-					context.var_set.insert (variable, VariableState.BOUND);
-					binding_list.list.append (binding);
-					break;
-				}
-				current_context = current_context.parent_context;
-			}
-		}
-		return binding_list;
-	}
-
-	internal void add_variable_binding (StringBuilder sql, VariableBinding binding, VariableState variable_state) {
-		var binding_list = get_variable_binding_list (binding.variable);
-		if (binding_list == null) {
-			binding_list = new VariableBindingList ();
-			if (triple_context != null) {
-				triple_context.variables.append (binding.variable);
-				triple_context.var_bindings.insert (binding.variable, binding_list);
-			}
-
-			sql.append_printf ("%s AS %s, ",
-				binding.sql_expression,
-				binding.variable.sql_expression);
-
-			if (binding.data_type == PropertyType.DATETIME) {
-				sql.append_printf ("%s AS %s, ",
-					binding.get_extra_sql_expression ("localDate"),
-					binding.variable.get_extra_sql_expression ("localDate"));
-				sql.append_printf ("%s AS %s, ",
-					binding.get_extra_sql_expression ("localTime"),
-					binding.variable.get_extra_sql_expression ("localTime"));
-			}
-
-			context.var_set.insert (binding.variable, variable_state);
-		}
-		binding_list.list.append (binding);
-		if (binding.variable.binding == null) {
-			binding.variable.binding = binding;
-		}
-	}
-
-	private void parse_object (StringBuilder sql, bool in_simple_optional = false) throws Sparql.Error {
-		long begin_sql_len = sql.len;
-
-		bool object_is_var;
-		string object = parse_var_or_term (sql, out object_is_var);
-
-		string db_table = null;
-		bool rdftype = false;
-		bool share_table = true;
-		bool is_fts_match = false;
-
-		bool newtable;
-		DataTable table;
-		Property prop = null;
-
-		Class subject_type = null;
-
-		var ontologies = manager.get_ontologies ();
-
-		if (!current_predicate_is_var) {
-			prop = ontologies.get_property_by_uri (current_predicate);
-
-			if (current_predicate == "http://www.w3.org/1999/02/22-rdf-syntax-ns#type"
-			    && !object_is_var && current_graph == null) {
-				// rdf:type query
-				// avoid special casing if GRAPH is used as graph matching is not supported when using class tables
-				rdftype = true;
-				var cl = ontologies.get_class_by_uri (object);
-				if (cl == null) {
-					throw new Sparql.Error.UNKNOWN_CLASS ("Unknown class `%s'".printf (object));
-				}
-				db_table = cl.name;
-				subject_type = cl;
-			} else if (prop == null) {
-				if (current_predicate == "http://www.tracker-project.org/ontologies/fts#match") {
-					// fts:match
-					db_table = "fts5";
-					share_table = false;
-					is_fts_match = true;
-					fts_subject = context.get_variable (current_subject);
-				} else {
-					throw new Sparql.Error.UNKNOWN_PROPERTY ("Unknown property `%s'".printf (current_predicate));
-				}
-			} else {
-				if (current_predicate == "http://www.w3.org/2000/01/rdf-schema#domain"
-				    && current_subject_is_var
-				    && !object_is_var) {
-					// rdfs:domain
-					var domain = ontologies.get_class_by_uri (object);
-					if (domain == null) {
-						throw new Sparql.Error.UNKNOWN_CLASS ("Unknown class `%s'".printf (object));
-					}
-					var pv = context.predicate_variable_map.lookup (context.get_variable (current_subject));
-					if (pv == null) {
-						pv = new PredicateVariable (manager);
-						context.predicate_variable_map.insert (context.get_variable (current_subject), pv);
-					}
-					pv.domain = domain;
-				}
-
-				if (current_subject_is_var) {
-					// Domain specific index might be a possibility, let's check
-					Variable v = context.get_variable (current_subject);
-					VariableBindingList list = triple_context.var_bindings.lookup (v);
-
-					if (list != null && list.list != null) {
-						bool stop = false;
-						foreach (Class cl in prop.get_domain_indexes ()) {
-							foreach (VariableBinding b in list.list) {
-								if (b.type == cl) {
-									db_table = cl.name;
-									stop = true;
-									break;
-								}
-							}
-							if (stop) {
-								break;
-							}
-						}
-					}
-				}
-
-				if (db_table == null)
-					db_table = prop.table_name;
-
-				if (prop.multiple_values) {
-					// we can never share the table with multiple triples
-					// for multi value properties as a property may consist of multiple rows
-					share_table = false;
-				}
-				subject_type = prop.domain;
-
-				if (in_simple_optional && context.var_set.lookup (context.get_variable (current_subject)) == 0) {
-					// use subselect instead of join in simple optional where the subject is the unbound variable
-					// this can only happen with inverse functional properties
-					var binding = new VariableBinding ();
-					binding.data_type = PropertyType.RESOURCE;
-					binding.variable = context.get_variable (current_subject);
-
-					assert (triple_context.var_bindings.lookup (binding.variable) == null);
-					var binding_list = new VariableBindingList ();
-					triple_context.variables.append (binding.variable);
-					triple_context.var_bindings.insert (binding.variable, binding_list);
-
-					// need to use table and column name for object, can't refer to variable in nested select
-					var object_binding = triple_context.var_bindings.lookup (context.get_variable (object)).list.data;
-
-					sql.append_printf ("(SELECT ID FROM \"%s\" WHERE \"%s\" = %s) AS %s, ",
-						db_table,
-						prop.name,
-						object_binding.sql_expression,
-						binding.variable.sql_expression);
-
-					context.var_set.insert (binding.variable, VariableState.OPTIONAL);
-					binding_list.list.append (binding);
-
-					assert (binding.variable.binding == null);
-					binding.variable.binding = binding;
-
-					return;
-				}
-			}
-			table = get_table (current_subject, db_table, share_table, out newtable);
-		} else {
-			// variable in predicate
-			newtable = true;
-			table = new DataTable ();
-			table.predicate_variable = context.predicate_variable_map.lookup (context.get_variable (current_predicate));
-			if (table.predicate_variable == null) {
-				table.predicate_variable = new PredicateVariable (manager);
-				context.predicate_variable_map.insert (context.get_variable (current_predicate), table.predicate_variable);
-			}
-			if (!current_subject_is_var) {
-				// single subject
-				table.predicate_variable.subject = current_subject;
-			}
-			if (!object_is_var) {
-				// single object
-				table.predicate_variable.object = object;
-			}
-			if (current_graph != null) {
-				table.predicate_variable.return_graph = true;
-			}
-			table.sql_query_tablename = current_predicate + (++counter).to_string ();
-			triple_context.tables.append (table);
-
-			// add to variable list
-			var binding = new VariableBinding ();
-			binding.data_type = PropertyType.RESOURCE;
-			binding.variable = context.get_variable (current_predicate);
-			binding.table = table;
-			binding.sql_db_column_name = "predicate";
-
-			add_variable_binding (sql, binding, VariableState.BOUND);
-		}
-
-		if (newtable) {
-			if (current_subject_is_var) {
-				var binding = new VariableBinding ();
-				binding.data_type = PropertyType.RESOURCE;
-				binding.variable = context.get_variable (current_subject);
-				binding.table = table;
-				binding.type = subject_type;
-				if (is_fts_match) {
-					binding.sql_db_column_name = "rowid";
-				} else {
-					binding.sql_db_column_name = "ID";
-				}
-
-				add_variable_binding (sql, binding, VariableState.BOUND);
-			} else {
-				var binding = new LiteralBinding ();
-				binding.data_type = PropertyType.RESOURCE;
-				binding.literal = current_subject;
-				// binding.data_type = triple.subject.type;
-				binding.table = table;
-				binding.sql_db_column_name = "ID";
-				triple_context.bindings.append (binding);
-			}
-		}
-
-		if (!rdftype) {
-			if (object_is_var) {
-				var binding = new VariableBinding ();
-				binding.variable = context.get_variable (object);
-				binding.table = table;
-				if (prop != null) {
-
-					binding.type = prop.range;
-
-					binding.data_type = prop.data_type;
-					binding.sql_db_column_name = prop.name;
-					if (!prop.multiple_values) {
-						// for single value properties, row may have NULL
-						// in any column except the ID column
-						binding.maybe_null = true;
-						binding.in_simple_optional = in_simple_optional;
-					}
-				} else {
-					// variable as predicate
-					binding.data_type = PropertyType.STRING;
-					binding.sql_db_column_name = "object";
-					binding.maybe_null = true;
-				}
-
-				VariableState state;
-				if (in_simple_optional) {
-					state = VariableState.OPTIONAL;
-				} else {
-					state = VariableState.BOUND;
-				}
-
-				add_variable_binding (sql, binding, state);
-			} else if (is_fts_match) {
-				var binding = new LiteralBinding ();
-				binding.is_fts_match = true;
-				binding.literal = object;
-				// binding.data_type = triple.object.type;
-				binding.table = table;
-				binding.sql_db_column_name = "fts5";
-				triple_context.bindings.append (binding);
-
-				sql.append_printf ("\"%s\".\"rowid\" AS \"ID\", ",
-				                   binding.table.sql_query_tablename);
-				sql.append_printf ("\"%s\".\"rank\" AS \"%s_u_rank\", ",
-				                   binding.table.sql_query_tablename,
-				                   context.get_variable (current_subject).name);
-			} else {
-				var binding = new LiteralBinding ();
-				binding.literal = object;
-				// binding.data_type = triple.object.type;
-				binding.table = table;
-				if (prop != null) {
-					binding.data_type = prop.data_type;
-					binding.sql_db_column_name = prop.name;
-				} else {
-					// variable as predicate
-					binding.sql_db_column_name = "object";
-				}
-				triple_context.bindings.append (binding);
-			}
-
-			if (current_graph != null) {
-				if (current_graph_is_var) {
-					var binding = new VariableBinding ();
-					binding.variable = context.get_variable (current_graph);
-					binding.table = table;
-					binding.data_type = PropertyType.RESOURCE;
-
-					if (prop != null) {
-						binding.sql_db_column_name = prop.name + ":graph";
-					} else {
-						// variable as predicate
-						binding.sql_db_column_name = "graph";
-					}
-
-					binding.maybe_null = true;
-					binding.in_simple_optional = in_simple_optional;
-
-					VariableState state;
-					if (in_simple_optional) {
-						state = VariableState.OPTIONAL;
-					} else {
-						state = VariableState.BOUND;
-					}
-
-					add_variable_binding (sql, binding, state);
-				} else {
-					var binding = new LiteralBinding ();
-					binding.literal = current_graph;
-					binding.table = table;
-					binding.data_type = PropertyType.RESOURCE;
-
-					if (prop != null) {
-						binding.sql_db_column_name = prop.name + ":graph";
-					} else {
-						// variable as predicate
-						binding.sql_db_column_name = "graph";
-					}
-
-					triple_context.bindings.append (binding);
-				}
-			}
-		}
-
-		if (sql.len == begin_sql_len) {
-			// no SELECT expression was added, add dummy expression
-			// this is required in cases where no values need to be retrieved
-			sql.append ("1, ");
-		}
-	}
-
-	private DataTable get_table (string subject, string db_table, bool share_table, out bool newtable) {
-		string tablestring = "%s.%s".printf (subject, db_table);
-		DataTable table = null;
-		newtable = false;
-		if (share_table) {
-			table = triple_context.table_map.lookup (tablestring);
-		}
-		if (table == null) {
-			newtable = true;
-			table = new DataTable ();
-			table.sql_db_tablename = db_table;
-			table.sql_query_tablename = db_table + (++counter).to_string ();
-			triple_context.tables.append (table);
-			triple_context.table_map.insert (tablestring, table);
-		}
-		return table;
-	}
-}
diff --git a/src/libtracker-data/tracker-sparql-query.vala b/src/libtracker-data/tracker-sparql-query.vala
deleted file mode 100644
index 54ce57003..000000000
--- a/src/libtracker-data/tracker-sparql-query.vala
+++ /dev/null
@@ -1,1102 +0,0 @@
-/*
- * Copyright (C) 2008-2010, Nokia
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA  02110-1301, USA.
- */
-
-namespace Tracker.Sparql {
-	enum VariableState {
-		NONE,
-		BOUND,
-		OPTIONAL
-	}
-
-	enum UpdateType {
-		DELETE,
-		INSERT,
-		UPDATE
-	}
-
-	// Represents a SQL table
-	class DataTable : Object {
-		public string sql_db_tablename; // as in db schema
-		public string sql_query_tablename; // temp. name, generated
-		public PredicateVariable predicate_variable;
-	}
-
-	abstract class DataBinding : Object {
-		public PropertyType data_type;
-		public DataTable table;
-		public string sql_db_column_name;
-		public string sql_expression {
-			get {
-				if (this._sql_expression == null && table != null) {
-					this._sql_expression = "\"%s\".\"%s\"".printf (table.sql_query_tablename, sql_db_column_name);
-				}
-				return this._sql_expression;
-			}
-			set {
-				this._sql_expression = value;
-			}
-		}
-		string? _sql_expression;
-		public string get_extra_sql_expression (string suffix) {
-			return "\"%s\".\"%s:%s\"".printf (table.sql_query_tablename, sql_db_column_name, suffix);
-		}
-	}
-
-	// Represents a mapping of a SPARQL literal to a SQL table and column
-	class LiteralBinding : DataBinding {
-		public bool is_fts_match;
-		public string literal;
-	}
-
-	// Represents a mapping of a SPARQL variable to a SQL table and column
-	class VariableBinding : DataBinding {
-		public weak Variable variable;
-		// Specified whether SQL column may contain NULL entries
-		public bool maybe_null;
-		public bool in_simple_optional;
-		public Class? type;
-	}
-
-	class VariableBindingList : Object {
-		public List<VariableBinding> list;
-	}
-
-	class Variable : Object {
-		public string name { get; private set; }
-		public int index { get; private set; }
-		public string sql_expression { get; private set; }
-		public VariableBinding binding;
-		string sql_identifier;
-
-		public Variable (string name, int index) {
-			this.name = name;
-			this.index = index;
-			this.sql_identifier = "%d_u".printf (index);
-			this.sql_expression = "\"%s\"".printf (sql_identifier);
-		}
-
-		public string get_extra_sql_expression (string suffix) {
-			return "\"%s:%s\"".printf (sql_identifier, suffix);
-		}
-
-		public static bool equal (Variable a, Variable b) {
-			return a.index == b.index;
-		}
-
-		public static uint hash (Variable variable) {
-			return (uint) variable.index;
-		}
-	}
-
-	class Context {
-		public weak Query query;
-
-		public Context? parent_context;
-		// All SPARQL variables within a subgraph pattern (used by UNION)
-		// value is VariableState
-		public HashTable<Variable,int> var_set;
-
-		public HashTable<string,Variable> var_map;
-		// All selected SPARQL variables (used by compositional subqueries)
-		public HashTable<Variable,int> select_var_set;
-
-		// Variables used as predicates
-		public HashTable<Variable,PredicateVariable> predicate_variable_map;
-
-		public bool scalar_subquery;
-		public bool need_binding_expression;
-
-		public Context (Query query, Context? parent_context = null) {
-			this.query = query;
-			this.parent_context = parent_context;
-			this.var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-
-			if (parent_context == null) {
-				select_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-				var_map = new HashTable<string,Variable>.full (str_hash, str_equal, g_free, g_object_unref);
-				predicate_variable_map = new HashTable<Variable,PredicateVariable>.full (Variable.hash, Variable.equal, g_object_unref, g_object_unref);
-			} else {
-				select_var_set = parent_context.select_var_set;
-				var_map = parent_context.var_map;
-				predicate_variable_map = parent_context.predicate_variable_map;
-			}
-		}
-
-		public Context.subquery (Query query, Context parent_context) {
-			this.query = query;
-			this.parent_context = parent_context;
-			this.var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-
-			select_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null);
-			var_map = parent_context.var_map;
-			predicate_variable_map = new HashTable<Variable,PredicateVariable>.full (Variable.hash, Variable.equal, g_object_unref, g_object_unref);
-			scalar_subquery = true;
-		}
-
-		internal unowned Variable get_variable (string name) {
-			unowned Variable result = this.var_map.lookup (name);
-			if (result == null) {
-				var variable = new Variable (name, ++query.last_var_index);
-				this.var_map.insert (name, variable);
-
-				result = variable;
-			}
-			return result;
-		}
-	}
-
-	class SelectContext : Context {
-		public PropertyType type;
-		public PropertyType[] types = {};
-		public string[] variable_names = {};
-
-		public SelectContext (Query query, Context? parent_context = null) {
-			base (query, parent_context);
-		}
-
-		public SelectContext.subquery (Query query, Context parent_context) {
-			base.subquery (query, parent_context);
-		}
-	}
-
-	class Solution {
-		public HashTable<string,int?> hash;
-		public GenericArray<string> values;
-		public int solution_index;
-
-		public Solution () {
-			this.hash = new HashTable<string,int?> (str_hash, str_equal);
-			this.values = new GenericArray<string> ();
-		}
-
-		public string? lookup (string variable_name) {
-			int? variable_index = hash.get (variable_name);
-			if (variable_index == null) {
-				return null;
-			}
-			return values[solution_index * hash.size () + variable_index];
-		}
-	}
-}
-
-public class Tracker.Sparql.Query : Object {
-	SparqlScanner scanner;
-
-	// token buffer
-	TokenInfo[] tokens;
-	// index of current token in buffer
-	int index;
-	// number of tokens in buffer
-	int size;
-
-	const int BUFFER_SIZE = 32;
-
-	struct TokenInfo {
-		public SparqlTokenType type;
-		public SourceLocation begin;
-		public SourceLocation end;
-	}
-
-	const string FN_NS = "http://www.w3.org/2005/xpath-functions#";
-
-	string query_string;
-	bool update_extensions;
-
-	internal Expression expression;
-	internal Pattern pattern;
-
-	string current_graph;
-	string current_subject;
-	bool current_subject_is_var;
-	string current_predicate;
-	bool current_predicate_is_var;
-
-	// SILENT => ignore (non-syntax) errors
-	bool silent;
-
-	HashTable<string,string> prefix_map;
-
-	// All SPARQL literals
-	internal List<LiteralBinding> bindings;
-
-	internal Context context;
-
-	int bnodeid = 0;
-	// base UUID used for blank nodes
-	uchar[] base_uuid;
-	HashTable<string,string> blank_nodes;
-
-	public Data.Manager manager;
-
-	// Keep track of used SQL identifiers for SPARQL variables
-	public int last_var_index;
-
-	public bool no_cache { get; set; }
-
-	public Query (Data.Manager manager, string query) {
-		no_cache = false; /* Start with false, expression sets it */
-		tokens = new TokenInfo[BUFFER_SIZE];
-		prefix_map = new HashTable<string,string>.full (str_hash, str_equal, g_free, g_free);
-
-		base_uuid = new uchar[16];
-		uuid_generate (base_uuid);
-
-		this.query_string = query;
-		this.manager = manager;
-
-		expression = new Expression (this);
-		pattern = new Pattern (this);
-	}
-
-	public Query.update (Data.Manager manager, string query) {
-		this (manager, query);
-		this.update_extensions = true;
-	}
-
-	string get_uuid_for_name (uchar[] base_uuid, string name) {
-		var checksum = new Checksum (ChecksumType.SHA1);
-		// base UUID, unique per file
-		checksum.update (base_uuid, 16);
-
-		// node ID
-		checksum.update ((uchar[]) name, -1);
-
-		string sha1 = checksum.get_string ();
-
-		// generate name based uuid
-		return "urn:uuid:%.8s-%.4s-%.4s-%.4s-%.12s".printf (
-			sha1, sha1.substring (8), sha1.substring (12), sha1.substring (16), sha1.substring (20));
-	}
-
-	internal string generate_bnodeid (string? user_bnodeid) {
-		// user_bnodeid is NULL for anonymous nodes
-		if (user_bnodeid == null) {
-			return ":%d".printf (++bnodeid);
-		} else {
-			string uri = null;
-
-			if (blank_nodes != null) {
-				uri = blank_nodes.lookup (user_bnodeid);
-				if (uri != null) {
-					return uri;
-				}
-			}
-
-			uri = get_uuid_for_name (base_uuid, user_bnodeid);
-
-			if (blank_nodes != null) {
-				var iface = manager.get_db_interface ();
-				while (Data.query_resource_id (manager, iface, uri) > 0) {
-					// uri collision, generate new UUID
-					uchar[] new_base_uuid = new uchar[16];
-					uuid_generate (new_base_uuid);
-					uri = get_uuid_for_name (new_base_uuid, user_bnodeid);
-				}
-
-				blank_nodes.insert (user_bnodeid, uri);
-			}
-
-			return uri;
-		}
-	}
-
-	internal bool next () throws Sparql.Error {
-		index = (index + 1) % BUFFER_SIZE;
-		size--;
-		if (size <= 0) {
-			SourceLocation begin, end;
-			SparqlTokenType type = scanner.read_token (out begin, out end);
-			tokens[index].type = type;
-			tokens[index].begin = begin;
-			tokens[index].end = end;
-			size = 1;
-		}
-		return (tokens[index].type != SparqlTokenType.EOF);
-	}
-
-	internal SparqlTokenType current () {
-		return tokens[index].type;
-	}
-
-	internal SparqlTokenType last () {
-		int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE;
-		return tokens[last_index].type;
-	}
-
-	internal bool accept (SparqlTokenType type) throws Sparql.Error {
-		if (current () == type) {
-			next ();
-			return true;
-		}
-		return false;
-	}
-
-	internal void optional (SparqlTokenType type) throws Sparql.Error {
-		if (current () == type)
-			next ();
-	}
-
-	internal Sparql.Error get_error (string msg) {
-		return new Sparql.Error.PARSE ("%d.%d: syntax error, %s".printf (tokens[index].begin.line, tokens[index].begin.column, msg));
-	}
-
-	internal Sparql.Error get_internal_error (string msg) {
-		return new Sparql.Error.INTERNAL ("%d.%d: %s".printf (tokens[index].begin.line, tokens[index].begin.column, msg));
-	}
-
-	internal bool expect (SparqlTokenType type) throws Sparql.Error {
-		if (accept (type)) {
-			return true;
-		}
-
-		throw get_error ("expected %s".printf (type.to_string ()));
-	}
-
-	internal SourceLocation get_location () {
-		return tokens[index].begin;
-	}
-
-	internal void set_location (SourceLocation location) {
-		scanner.seek (location);
-		size = 0;
-		index = 0;
-		try {
-			next ();
-		} catch (Sparql.Error e) {
-			// this should never happen as this is the second time we scan this token
-			critical ("internal error: next in set_location failed");
-		}
-	}
-
-	internal string get_last_string (int strip = 0) {
-		int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE;
-		return ((string) (tokens[last_index].begin.pos + strip)).substring (0, (int) (tokens[last_index].end.pos - tokens[last_index].begin.pos - 2 * strip));
-	}
-
-	private void parse_prologue () throws Sparql.Error {
-		if (accept (SparqlTokenType.BASE)) {
-			expect (SparqlTokenType.IRI_REF);
-		}
-		while (accept (SparqlTokenType.PREFIX)) {
-			string ns = "";
-			if (accept (SparqlTokenType.PN_PREFIX)) {
-				ns = get_last_string ();
-			}
-			expect (SparqlTokenType.COLON);
-			expect (SparqlTokenType.IRI_REF);
-			string uri = get_last_string (1);
-			prefix_map.insert (ns, uri);
-		}
-	}
-
-	private void prepare_execute () throws DBInterfaceError, Sparql.Error, DateError {
-		assert (!update_extensions);
-
-		scanner = new SparqlScanner ((char*) query_string, (long) query_string.length);
-		next ();
-
-		// declare fn prefix for XPath functions
-		prefix_map.insert ("fn", FN_NS);
-		var ontologies = manager.get_ontologies ();
-
-		foreach (Namespace ns in ontologies.get_namespaces ()) {
-			if (ns.prefix == null) {
-				critical ("Namespace does not specify a prefix: %s", ns.uri);
-				continue;
-			}
-			prefix_map.insert (ns.prefix, ns.uri);
-		}
-
-		parse_prologue ();
-	}
-
-
-	public DBCursor? execute_cursor () throws DBInterfaceError, Sparql.Error, DateError {
-
-		prepare_execute ();
-
-		switch (current ()) {
-		case SparqlTokenType.SELECT:
-			return execute_select_cursor ();
-		case SparqlTokenType.CONSTRUCT:
-			throw get_internal_error ("CONSTRUCT is not supported");
-		case SparqlTokenType.DESCRIBE:
-			throw get_internal_error ("DESCRIBE is not supported");
-		case SparqlTokenType.ASK:
-			return execute_ask_cursor ();
-		case SparqlTokenType.INSERT:
-		case SparqlTokenType.DELETE:
-		case SparqlTokenType.DROP:
-			throw get_error ("INSERT and DELETE are not supported in query mode");
-		default:
-			throw get_error ("expected SELECT or ASK");
-		}
-	}
-
-	public Variant? execute_update (bool blank) throws GLib.Error {
-		Variant result = null;
-		assert (update_extensions);
-
-		scanner = new SparqlScanner ((char*) query_string, (long) query_string.length);
-		next ();
-
-		// declare fn prefix for XPath functions
-		prefix_map.insert ("fn", FN_NS);
-		var ontologies = manager.get_ontologies ();
-
-		foreach (Namespace ns in ontologies.get_namespaces ()) {
-			if (ns.prefix == null) {
-				critical ("Namespace does not specify a prefix: %s", ns.uri);
-				continue;
-			}
-			prefix_map.insert (ns.prefix, ns.uri);
-		}
-
-		parse_prologue ();
-
-		// SPARQL update supports multiple operations in a single query
-		VariantBuilder? ublank_nodes = null;
-
-		if (blank) {
-			ublank_nodes = new VariantBuilder ((VariantType) "aaa{ss}");
-		}
-
-		while (current () != SparqlTokenType.EOF) {
-			switch (current ()) {
-			case SparqlTokenType.WITH:
-			case SparqlTokenType.INSERT:
-			case SparqlTokenType.DELETE:
-				if (blank) {
-					ublank_nodes.open ((VariantType) "aa{ss}");
-					execute_insert_delete (ublank_nodes);
-					ublank_nodes.close ();
-				} else {
-					execute_insert_delete (null);
-				}
-				break;
-			case SparqlTokenType.DROP:
-				throw get_internal_error ("DROP GRAPH is not supported");
-			case SparqlTokenType.SELECT:
-			case SparqlTokenType.CONSTRUCT:
-			case SparqlTokenType.DESCRIBE:
-			case SparqlTokenType.ASK:
-				throw get_error ("SELECT, CONSTRUCT, DESCRIBE, and ASK are not supported in update mode");
-			default:
-				throw get_error ("expected INSERT or DELETE");
-			}
-
-			// semicolon is used to separate multiple operations in the current SPARQL Update draft
-			// keep it optional for now to reatin backward compatibility
-			optional (SparqlTokenType.SEMICOLON);
-		}
-
-		if (blank) {
-			result = ublank_nodes.end ();
-		}
-
-		return result;
-	}
-
-	private DBStatement prepare_for_exec (DBInterface iface, string sql) throws DBInterfaceError, Sparql.Error, DateError {
-		var stmt = iface.create_statement (no_cache ? DBStatementCacheType.NONE : DBStatementCacheType.SELECT, "%s", sql);
-
-		// set literals specified in query
-		int i = 0;
-		foreach (LiteralBinding binding in bindings) {
-			if (binding.data_type == PropertyType.BOOLEAN) {
-				if (binding.literal == "true" || binding.literal == "1") {
-					stmt.bind_int (i, 1);
-				} else if (binding.literal == "false" || binding.literal == "0") {
-					stmt.bind_int (i, 0);
-				} else {
-					throw new Sparql.Error.TYPE ("`%s' is not a valid boolean".printf (binding.literal));
-				}
-			} else if (binding.data_type == PropertyType.DATE) {
-				stmt.bind_int (i, (int) string_to_date (binding.literal + "T00:00:00Z", null));
-			} else if (binding.data_type == PropertyType.DATETIME) {
-				stmt.bind_double (i, string_to_date (binding.literal, null));
-			} else if (binding.data_type == PropertyType.INTEGER) {
-				stmt.bind_int (i, int.parse (binding.literal));
-			} else {
-				stmt.bind_text (i, binding.literal);
-			}
-			i++;
-		}
-
-		return stmt;
-	}
-
-	private DBCursor? exec_sql_cursor (DBInterface iface, string sql, PropertyType[]? types, string[]? variable_names) throws DBInterfaceError, Sparql.Error, DateError {
-		var stmt = prepare_for_exec (iface, sql);
-
-		return stmt.start_sparql_cursor (types, variable_names);
-	}
-
-	private string get_select_query (out SelectContext context) throws DBInterfaceError, Sparql.Error, DateError {
-		// SELECT query
-
-		// build SQL
-		var sql = new StringBuilder ();
-		context = pattern.translate_select (sql);
-
-		expect (SparqlTokenType.EOF);
-
-		return sql.str;
-	}
-
-	private DBCursor? execute_select_cursor () throws DBInterfaceError, Sparql.Error, DateError {
-		SelectContext context;
-		string sql = get_select_query (out context);
-		var iface = manager.get_db_interface ();
-
-		return exec_sql_cursor (iface, sql, context.types, context.variable_names);
-	}
-
-	private string get_ask_query () throws DBInterfaceError, Sparql.Error, DateError {
-		// ASK query
-
-		var pattern_sql = new StringBuilder ();
-
-		// build SQL
-		var sql = new StringBuilder ();
-		sql.append ("SELECT CASE EXISTS ( ");
-
-		expect (SparqlTokenType.ASK);
-
-		optional (SparqlTokenType.WHERE);
-
-		context = pattern.translate_group_graph_pattern (pattern_sql);
-
-		// select from results of WHERE clause
-		sql.append (pattern_sql.str);
-		sql.append (" ) WHEN 1 THEN 'true' WHEN 0 THEN 'false' ELSE NULL END");
-
-		if (accept (SparqlTokenType.GROUP) || accept (SparqlTokenType.ORDER) ||
-		    accept (SparqlTokenType.OFFSET) || accept (SparqlTokenType.LIMIT)) {
-			throw get_error ("invalid use of %s in ASK".printf (last().to_string()));
-		}
-
-		expect (SparqlTokenType.EOF);
-
-		context = context.parent_context;
-
-		return sql.str;
-	}
-
-	private DBCursor? execute_ask_cursor () throws DBInterfaceError, Sparql.Error, DateError {
-		var iface = manager.get_db_interface ();
-		return exec_sql_cursor (iface, get_ask_query (), new PropertyType[] { PropertyType.BOOLEAN }, new string[] { "result" });
-	}
-
-	private void parse_from_or_into_param () throws Sparql.Error {
-		if (accept (SparqlTokenType.IRI_REF)) {
-			current_graph = get_last_string (1);
-		} else if (accept (SparqlTokenType.PN_PREFIX)) {
-			string ns = get_last_string ();
-			expect (SparqlTokenType.COLON);
-			current_graph = resolve_prefixed_name (ns, get_last_string ().substring (1));
-		} else {
-			expect (SparqlTokenType.COLON);
-			current_graph = resolve_prefixed_name ("", get_last_string ().substring (1));
-		}
-	}
-
-	private void execute_insert_delete (VariantBuilder? update_blank_nodes) throws GLib.Error {
-		bool blank = true;
-
-		// DELETE and/or INSERT
-
-		if (accept (SparqlTokenType.WITH)) {
-			parse_from_or_into_param ();
-		} else {
-			current_graph = null;
-		}
-
-		SourceLocation? delete_location = null;
-		SourceLocation? insert_location = null;
-		bool insert_is_update = false;
-		bool delete_where = false;
-		bool data = false;
-
-		var data_update = manager.get_data ();
-
-		// Sparql 1.1 defines deletes/inserts as a single
-		// operation with the syntax:
-		//   [DELETE {...}] [INSERT {...}] WHERE {...}
-
-		if (accept (SparqlTokenType.DELETE)) {
-			blank = false;
-
-			// SILENT => ignore (non-syntax) errors
-			silent = accept (SparqlTokenType.SILENT);
-
-			if (current_graph == null && accept (SparqlTokenType.FROM)) {
-				parse_from_or_into_param ();
-			}
-
-			if (current_graph == null && accept (SparqlTokenType.DATA)) {
-				// INSERT/DELETE DATA are simpler variants
-				// that don't support variables
-				data = true;
-			} else if (accept (SparqlTokenType.WHERE)) {
-				// DELETE WHERE is a short form where the pattern
-				// is also used as the template for deletion
-				delete_where = true;
-			}
-
-			delete_location = get_location ();
-
-			if (!data && !delete_where) {
-				skip_braces ();
-			}
-		}
-
-		if (!data && !delete_where && accept (SparqlTokenType.INSERT)) {
-			if (accept (SparqlTokenType.OR)) {
-				expect (SparqlTokenType.REPLACE);
-				insert_is_update = true;
-			}
-
-			if (!insert_is_update) {
-				// SILENT => ignore (non-syntax) errors
-				silent = accept (SparqlTokenType.SILENT);
-			}
-
-			if (current_graph == null && accept (SparqlTokenType.INTO)) {
-				parse_from_or_into_param ();
-			}
-
-			if (current_graph == null && accept (SparqlTokenType.DATA)) {
-				// INSERT/DELETE DATA are simpler variants
-				// that don't support variables
-				data = true;
-			}
-
-			if (current () != SparqlTokenType.OPEN_BRACE) {
-				throw get_error ("Expected '{' beginning a quad data/pattern block");
-			}
-
-			insert_location = get_location ();
-
-			if (!data) {
-				skip_braces ();
-			}
-		}
-
-		var pattern_sql = new StringBuilder ();
-
-		var sql = new StringBuilder ();
-
-		if (!data) {
-			if (delete_where || accept (SparqlTokenType.WHERE)) {
-				pattern.current_graph = current_graph;
-				context = pattern.translate_group_graph_pattern (pattern_sql);
-				pattern.current_graph = null;
-			} else {
-				context = new Context (this);
-
-				pattern_sql.append ("SELECT 1");
-			}
-		} else {
-			// WHERE pattern not supported for INSERT/DELETE DATA,
-			// nor unbound values in the quad data.
-			if (quad_data_unbound_var_count () > 0) {
-				throw get_error ("INSERT/DELETE DATA do not allow unbound values");
-			}
-
-			context = new Context (this);
-
-			pattern_sql.append ("SELECT 1");
-		}
-
-		var after_where = get_location ();
-
-		var solution = new Solution ();
-
-		// build SQL
-		sql.append ("SELECT ");
-		int var_idx = 0;
-		foreach (var variable in context.var_set.get_keys ()) {
-			if (var_idx > 0) {
-				sql.append (", ");
-			}
-
-			if (variable.binding == null) {
-				throw get_error ("use of undefined variable `%s'".printf (variable.name));
-			}
-			Expression.append_expression_as_string (sql, variable.sql_expression, variable.binding.data_type);
-
-			solution.hash.insert (variable.name, var_idx++);
-		}
-
-		if (var_idx == 0) {
-			sql.append ("1");
-		}
-
-		// select from results of WHERE clause
-		sql.append (" FROM (");
-		sql.append (pattern_sql.str);
-		sql.append (")");
-
-		var iface = manager.get_writable_db_interface ();
-		var cursor = exec_sql_cursor (iface, sql.str, null, null);
-
-		int n_solutions = 0;
-		while (cursor.next ()) {
-			// get values of all variables to be bound
-			for (var_idx = 0; var_idx < solution.hash.size (); var_idx++) {
-				solution.values.add (cursor.get_string (var_idx));
-			}
-			n_solutions++;
-		}
-
-		cursor = null;
-
-		// Iterate over all solutions twice
-		// First handle deletes
-		if (delete_location != null) {
-			for (int i = 0; i < n_solutions; i++) {
-				solution.solution_index = i;
-				set_location (delete_location);
-				parse_construct_triples_block (solution, UpdateType.DELETE);
-				data_update.update_buffer_might_flush ();
-			}
-
-			// Force flush on delete/insert operations,
-			// so the elements are already removed at
-			// the time of insertion.
-			if (insert_location != null)
-				data_update.update_buffer_flush ();
-		}
-
-		// Then handle inserts/updates
-		if (insert_location != null) {
-			for (int i = 0; i < n_solutions; i++) {
-				uuid_generate (base_uuid);
-				blank_nodes = new HashTable<string,string>.full (str_hash, str_equal, g_free, g_free);
-				solution.solution_index = i;
-
-				set_location (insert_location);
-				parse_construct_triples_block (solution,
-							       insert_is_update ?
-							       UpdateType.UPDATE :
-							       UpdateType.INSERT);
-
-				if (blank && update_blank_nodes != null) {
-					update_blank_nodes.add_value (blank_nodes);
-				}
-
-				data_update.update_buffer_might_flush ();
-			}
-		}
-
-		solution = null;
-
-		if (!data) {
-			// reset location to the end of the update
-			set_location (after_where);
-		}
-
-		// ensure possible WHERE clause in next part gets the correct results
-		data_update.update_buffer_flush ();
-		bindings = null;
-
-		context = context.parent_context;
-	}
-
-	internal string resolve_prefixed_name (string prefix, string local_name) throws Sparql.Error {
-		string ns = prefix_map.lookup (prefix);
-		if (ns == null) {
-			throw get_error ("use of undefined prefix `%s'".printf (prefix));
-		}
-		return ns + local_name;
-	}
-
-	private int quad_data_unbound_var_count () throws Sparql.Error {
-		SourceLocation current_pos = get_location ();
-		int n_braces = 1;
-		int n_unbound = 0;
-
-		expect (SparqlTokenType.OPEN_BRACE);
-		while (n_braces > 0) {
-			if (accept (SparqlTokenType.OPEN_BRACE)) {
-				n_braces++;
-			} else if (accept (SparqlTokenType.CLOSE_BRACE)) {
-				n_braces--;
-			} else if (current () == SparqlTokenType.EOF) {
-				throw get_error ("unexpected end of query, expected }");
-			} else {
-				if (current () == SparqlTokenType.VAR)
-					n_unbound++;
-				// ignore everything else
-				next ();
-			}
-		}
-
-		set_location (current_pos);
-		return n_unbound;
-	}
-
-	private void skip_braces () throws Sparql.Error {
-		expect (SparqlTokenType.OPEN_BRACE);
-		int n_braces = 1;
-		while (n_braces > 0) {
-			if (accept (SparqlTokenType.OPEN_BRACE)) {
-				n_braces++;
-			} else if (accept (SparqlTokenType.CLOSE_BRACE)) {
-				n_braces--;
-			} else if (current () == SparqlTokenType.EOF) {
-				throw get_error ("unexpected end of query, expected }");
-			} else {
-				// ignore everything else
-				next ();
-			}
-		}
-	}
-
-	private void parse_construct_triples_block (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError {
-		expect (SparqlTokenType.OPEN_BRACE);
-
-		while (current () != SparqlTokenType.CLOSE_BRACE) {
-			bool is_null = false;
-
-			if (accept (SparqlTokenType.GRAPH)) {
-				var old_graph = current_graph;
-				current_graph = parse_construct_var_or_term (var_value_map, type, out is_null);
-
-				if (is_null) {
-					throw get_error ("'null' not supported for graph");
-				}
-
-				expect (SparqlTokenType.OPEN_BRACE);
-
-				while (current () != SparqlTokenType.CLOSE_BRACE) {
-					current_subject = parse_construct_var_or_term (var_value_map, type, out is_null);
-
-					if (is_null) {
-						throw get_error ("'null' not supported for subject");
-					}
-
-					parse_construct_property_list_not_empty (var_value_map, type);
-					if (!accept (SparqlTokenType.DOT)) {
-						// no triples following
-						break;
-					}
-				}
-
-				expect (SparqlTokenType.CLOSE_BRACE);
-
-				current_graph = old_graph;
-
-				optional (SparqlTokenType.DOT);
-			} else {
-				current_subject = parse_construct_var_or_term (var_value_map, type, out is_null);
-
-				if (is_null) {
-					throw get_error ("'null' not supported for subject");
-				}
-
-				parse_construct_property_list_not_empty (var_value_map, type);
-				if (!accept (SparqlTokenType.DOT) && current () != SparqlTokenType.GRAPH) {
-					// neither GRAPH nor triples following
-					break;
-				}
-			}
-		}
-
-		expect (SparqlTokenType.CLOSE_BRACE);
-	}
-
-	bool anon_blank_node_open = false;
-
-	private string? parse_construct_var_or_term (Solution var_value_map, UpdateType type, out bool is_null) throws Sparql.Error, DateError {
-		string result = "";
-		is_null = false;
-		if (current () == SparqlTokenType.VAR) {
-			next ();
-			result = var_value_map.lookup (get_last_string ().substring (1));
-		} else if (current () == SparqlTokenType.IRI_REF) {
-			next ();
-			result = get_last_string (1);
-		} else if (current () == SparqlTokenType.PN_PREFIX) {
-			// prefixed name with namespace foo:bar
-			next ();
-			string ns = get_last_string ();
-			expect (SparqlTokenType.COLON);
-			result = resolve_prefixed_name (ns, get_last_string ().substring (1));
-		} else if (current () == SparqlTokenType.COLON) {
-			// prefixed name without namespace :bar
-			next ();
-			result = resolve_prefixed_name ("", get_last_string ().substring (1));
-		} else if (accept (SparqlTokenType.BLANK_NODE)) {
-			// _:foo
-			expect (SparqlTokenType.COLON);
-			result = generate_bnodeid (get_last_string ().substring (1));
-		} else if (current () == SparqlTokenType.MINUS) {
-			next ();
-			if (current () == SparqlTokenType.INTEGER ||
-			    current () == SparqlTokenType.DECIMAL ||
-			    current () == SparqlTokenType.DOUBLE) {
-				next ();
-				result = "-" + get_last_string ();
-			} else {
-				throw get_error ("expected variable or term");
-			}
-		} else if (current () == SparqlTokenType.INTEGER) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.NULL) {
-			next ();
-			result = "null";
-			is_null = true;
-		} else if (current () == SparqlTokenType.DECIMAL) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.DOUBLE) {
-			next ();
-			result = get_last_string ();
-		} else if (current () == SparqlTokenType.TRUE) {
-			next ();
-			result = "true";
-		} else if (current () == SparqlTokenType.FALSE) {
-			next ();
-			result = "false";
-		} else if (current () == SparqlTokenType.STRING_LITERAL1) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL2) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL_LONG1) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.STRING_LITERAL_LONG2) {
-			result = expression.parse_string_literal ();
-		} else if (current () == SparqlTokenType.OPEN_BRACKET) {
-
-			if (anon_blank_node_open) {
-				throw get_error ("no support for nested anonymous blank nodes");
-			}
-
-			anon_blank_node_open = true;
-			next ();
-
-			result = generate_bnodeid (null);
-
-			string old_subject = current_subject;
-			bool old_subject_is_var = current_subject_is_var;
-
-			current_subject = result;
-			parse_construct_property_list_not_empty (var_value_map, type);
-			expect (SparqlTokenType.CLOSE_BRACKET);
-			anon_blank_node_open = false;
-
-			current_subject = old_subject;
-			current_subject_is_var = old_subject_is_var;
-		} else {
-			throw get_error ("expected variable or term");
-		}
-		return result;
-	}
-
-	private void parse_construct_property_list_not_empty (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError {
-		while (true) {
-			var old_predicate = current_predicate;
-
-			current_predicate = null;
-			if (current () == SparqlTokenType.VAR) {
-				current_predicate_is_var = true;
-				next ();
-				current_predicate = var_value_map.lookup (get_last_string ().substring (1));
-			} else if (current () == SparqlTokenType.IRI_REF) {
-				next ();
-				current_predicate = get_last_string (1);
-			} else if (current () == SparqlTokenType.PN_PREFIX) {
-				next ();
-				string ns = get_last_string ();
-				expect (SparqlTokenType.COLON);
-				current_predicate = resolve_prefixed_name (ns, get_last_string ().substring (1));
-			} else if (current () == SparqlTokenType.COLON) {
-				next ();
-				current_predicate = resolve_prefixed_name ("", get_last_string ().substring (1));
-			} else if (current () == SparqlTokenType.A) {
-				next ();
-				current_predicate = "http://www.w3.org/1999/02/22-rdf-syntax-ns#type";
-			} else {
-				throw get_error ("expected non-empty property list");
-			}
-			parse_construct_object_list (var_value_map, type);
-
-			current_predicate = old_predicate;
-
-			if (accept (SparqlTokenType.SEMICOLON)) {
-				continue;
-			}
-			break;
-		}
-	}
-
-	private void parse_construct_object_list (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError {
-		while (true) {
-			parse_construct_object (var_value_map, type);
-			if (accept (SparqlTokenType.COMMA)) {
-				continue;
-			}
-			break;
-		}
-	}
-
-	private void parse_construct_object (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError {
-		bool is_null = false;
-		string object = parse_construct_var_or_term (var_value_map, type, out is_null);
-		var data = manager.get_data ();
-		if (current_subject == null || current_predicate == null || object == null) {
-			// the SPARQL specification says that triples containing unbound variables
-			// should be excluded from the output RDF graph of CONSTRUCT
-			return;
-		}
-		try {
-			if (type == UpdateType.UPDATE) {
-				// update triple in database
-				data.update_statement (current_graph, current_subject, current_predicate, is_null ? null : object);
-			} else if (type == UpdateType.DELETE) {
-				// delete triple from database
-				if (is_null) {
-					throw get_error ("'null' not supported in this mode");
-				}
-				data.delete_statement (current_graph, current_subject, current_predicate, object);
-			} else if (type == UpdateType.INSERT) {
-				// insert triple into database
-				if (is_null) {
-					throw get_error ("'null' not supported in this mode");
-				}
-				data.insert_statement (current_graph, current_subject, current_predicate, object);
-			}
-		} catch (Sparql.Error e) {
-			if (!silent) {
-				throw e;
-			}
-		} catch (DateError e) {
-			if (!silent) {
-				throw new Sparql.Error.TYPE (e.message);
-			}
-		}
-	}
-
-	[CCode (cname = "uuid_generate")]
-	public extern static void uuid_generate ([CCode (array_length = false)] uchar[] uuid);
-}
-