[tracker/subqueries] SPARQL: Fix type handling in select expressions

[Jürg Billeter <juergbi src gnome org>]

commit 1431e1615c4bb6f95d131ca47e2c091cf93013e6
Author: Jürg Billeter <j bitron ch>
Date:   Mon Dec 7 16:54:05 2009 +0100

    SPARQL: Fix type handling in select expressions
    
    Improves performance of COUNT.

 src/libtracker-data/tracker-sparql-query.vala |   56 +++++++++----------------
 1 files changed, 20 insertions(+), 36 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql-query.vala b/src/libtracker-data/tracker-sparql-query.vala
index 82f6fd4..db3138f 100644
--- a/src/libtracker-data/tracker-sparql-query.vala
+++ b/src/libtracker-data/tracker-sparql-query.vala
@@ -612,44 +612,31 @@ public class Tracker.SparqlQuery : Object {
 	}
 
 	void translate_select_expression (StringBuilder sql, bool subquery) throws SparqlError {
-		// FIXME: support AS ?var for all aggregation functions / expressions
+		long begin = sql.len;
+		var type = PropertyType.UNKNOWN;
+
 		if (accept (SparqlTokenType.COUNT)) {
 			sql.append ("COUNT(");
-			translate_expression_as_string (sql);
+			translate_expression (sql);
 			sql.append (")");
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.VAR);
-				string variable_name = get_last_string ().substring (1);
-				sql.append_printf (" AS %s", get_variable (variable_name).sql_expression);
-			}
+			type = PropertyType.INTEGER;
 		} else if (accept (SparqlTokenType.SUM)) {
 			sql.append ("SUM(");
-			translate_expression_as_string (sql);
+			type = translate_expression (sql);
 			sql.append (")");
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.PN_PREFIX);
-			}
 		} else if (accept (SparqlTokenType.AVG)) {
 			sql.append ("AVG(");
-			translate_expression_as_string (sql);
+			type = translate_expression (sql);
 			sql.append (")");
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.PN_PREFIX);
-			}
+			convert_expression_to_string (sql, type, begin);
 		} else if (accept (SparqlTokenType.MIN)) {
 			sql.append ("MIN(");
-			translate_expression_as_string (sql);
+			type = translate_expression (sql);
 			sql.append (")");
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.PN_PREFIX);
-			}
 		} else if (accept (SparqlTokenType.MAX)) {
 			sql.append ("MAX(");
-			translate_expression_as_string (sql);
+			type = translate_expression (sql);
 			sql.append (")");
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.PN_PREFIX);
-			}
 		} else if (accept (SparqlTokenType.GROUP_CONCAT)) {
 			sql.append ("GROUP_CONCAT(");
 			expect (SparqlTokenType.OPEN_PARENS);
@@ -659,20 +646,17 @@ public class Tracker.SparqlQuery : Object {
 			sql.append (escape_sql_string_literal (parse_string_literal ()));
 			sql.append (")");
 			expect (SparqlTokenType.CLOSE_PARENS);
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.PN_PREFIX);
-			}
+			type = PropertyType.STRING;
 		} else {
-			if (subquery) {
-				translate_expression (sql);
-			} else {
-				translate_expression_as_string (sql);
-			}
-			if (accept (SparqlTokenType.AS)) {
-				expect (SparqlTokenType.VAR);
-				string variable_name = get_last_string ().substring (1);
-				sql.append_printf (" AS %s", get_variable (variable_name).sql_expression);
-			}
+			type = translate_expression (sql);
+		}
+		if (!subquery) {
+			convert_expression_to_string (sql, type, begin);
+		}
+		if (accept (SparqlTokenType.AS)) {
+			expect (SparqlTokenType.VAR);
+			string variable_name = get_last_string ().substring (1);
+			sql.append_printf (" AS %s", get_variable (variable_name).sql_expression);
 		}
 	}