XPath: Replaced backtracking with lookahead in absolute path parsing

git-svn-id: http://pugixml.googlecode.com/svn/trunk@485 99668b35-9821-0410-8761-19e4c4f06640

1 files changed, 9 insertions, 23 deletions

diff --git a/src/pugixpath.cpp b/src/pugixpath.cpp
index 6262ff3..78127dc 100644
--- a/src/pugixpath.cpp
+++ b/src/pugixpath.cpp
@@ -881,12 +881,6 @@ namespace pugi
 			return m_cur;

 		}

 		

-		void reset(const char_t* state)

-		{

-			m_cur = state;

-			next();

-		}

-

 		void next()

 		{

 			contents_clear();

@@ -3079,25 +3073,17 @@ namespace pugi
 	    {

 			if (m_lexer.current() == lex_slash)

 			{

-				// Save state for next lexeme - that is, whatever follows '/'

-				const char_t* state = 0; // gcc3 "variable might be used uninitialized in this function" bug workaround

-				state = m_lexer.state();

-				

 				m_lexer.next();

 				

-				xpath_ast_node* n = 0; // gcc3 "variable might be used uninitialized in this function" bug workaround

-				n = new (m_alloc.node()) xpath_ast_node(ast_step_root, xpath_type_node_set);

-				

-				try

-				{

-					n = parse_relative_location_path(n);

-				}

-				catch (const xpath_exception&)

-				{

-					m_lexer.reset(state);

-				}

-				

-				return n;

+				xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_step_root, xpath_type_node_set);

+

+				// relative location path can start from axis_attribute, dot, double_dot, multiply and string lexemes; any other lexeme means standalone root path

+				lexeme_t l = m_lexer.current();

+

+				if (l == lex_string || l == lex_axis_attribute || l == lex_dot || l == lex_double_dot || l == lex_multiply)

+					return parse_relative_location_path(n);

+				else

+					return n;

 			}

 			else if (m_lexer.current() == lex_double_slash)

 			{