Method parse_primary_expression

UnitTests/TestApp/pugixml.cpp:9793–9892

PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall

	// PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
	xpath_ast_node* parse_primary_expression()
	{
		switch (_lexer.current())
		{
		case lex_var_ref:
		{
			xpath_lexer_string name = _lexer.contents();

			if (!_variables)
				throw_error("Unknown variable: variable set is not provided");

			xpath_variable* var = get_variable(_variables, name.begin, name.end);

			if (!var)
				throw_error("Unknown variable: variable set does not contain the given name");

			_lexer.next();

			return new (alloc_node()) xpath_ast_node(ast_variable, var->type(), var);
		}

		case lex_open_brace:
		{
			_lexer.next();

			xpath_ast_node* n = parse_expression();

			if (_lexer.current() != lex_close_brace)
				throw_error("Unmatched braces");

			_lexer.next();

			return n;
		}

		case lex_quoted_string:
		{
			const char_t* value = alloc_string(_lexer.contents());

			xpath_ast_node* n = new (alloc_node()) xpath_ast_node(ast_string_constant, xpath_type_string, value);
			_lexer.next();

			return n;
		}

		case lex_number:
		{
			double value = 0;

			if (!convert_string_to_number(_lexer.contents().begin, _lexer.contents().end, &value))
				throw_error_oom();

			xpath_ast_node* n = new (alloc_node()) xpath_ast_node(ast_number_constant, xpath_type_number, value);
			_lexer.next();

			return n;
		}