Method parse_path_expression

src/pugiXML/pugixml.cpp:9338–9385

PathExpr ::= LocationPath | FilterExpr | FilterExpr '/' RelativeLocationPath | FilterExpr '//' RelativeLocationPath

		//				| FilterExpr '/' RelativeLocationPath
		//				| FilterExpr '//' RelativeLocationPath
		xpath_ast_node* parse_path_expression()
		{
			// Clarification.
			// PathExpr begins with either LocationPath or FilterExpr.
			// FilterExpr begins with PrimaryExpr
			// PrimaryExpr begins with '$' in case of it being a variable reference,
			// '(' in case of it being an expression, string literal, number constant or
			// function call.

			if (_lexer.current() == lex_var_ref || _lexer.current() == lex_open_brace || 
				_lexer.current() == lex_quoted_string || _lexer.current() == lex_number ||
				_lexer.current() == lex_string)
			{
				if (_lexer.current() == lex_string)
				{
					// This is either a function call, or not - if not, we shall proceed with location path
					const char_t* state = _lexer.state();
					
					while (PUGI__IS_CHARTYPE(*state, ct_space)) ++state;
					
					if (*state != '(') return parse_location_path();

					// This looks like a function call; however this still can be a node-test. Check it.
					if (parse_node_test_type(_lexer.contents()) != nodetest_none) return parse_location_path();
				}
				
				xpath_ast_node* n = parse_filter_expression();

				if (_lexer.current() == lex_slash || _lexer.current() == lex_double_slash)
				{
					lexeme_t l = _lexer.current();
					_lexer.next();
					
					if (l == lex_double_slash)
					{
						if (n->rettype() != xpath_type_node_set) throw_error("Step has to be applied to node set");

						n = new (alloc_node()) xpath_ast_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
					}
	
					// select from location path
					return parse_relative_location_path(n);
				}

				return n;
			}
			else return parse_location_path();
		}

		// UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
		xpath_ast_node* parse_union_expression()