Appendix A - ScriptX Reference

This appendix provides a formal specification of the ScriptX language. It is intended as an entry point and reference for advanced users. It presents an annotated EBNF (Extended Backus-Naur Form) grammar of ScriptX. The complete EBNF grammar is listed separately at the end of the appendix.

The ScriptX grammar is organized into the following sections:

Topic	Discussion	Listing
Tokens and Literals	230	250
Types of Expression	236	251
Expression Syntax	239	252
Assignment and Variable Access	241	253
Flow of Control	243	253
Definition of Classes	244	254
Definition of Objects	246	254
Definition of Functions and Methods	247	255
Modules	248	255
Exception Handling	249	255

Reserved words and tokens, such as operators, that appear directly as shown in the input stream, are set in Courier boldface in lines of syntax, in lightface in body type. Non-terminals, units of syntax that are defined elsewhere in the grammar, are set in Palatino italics. Descriptive comments are used occasionally to indicate non-printing characters. Since ScriptX is not case sensitive, uppercase characters have been omitted.

Courier boldface		reserved words, operators, printing characters

Courier lightface		reserved words, operators, printing characters in body type

Palatino italics		non-terminals, units of syntax

Table A-1 lists the notations that are used in this grammar.

Table A-1: Notations used in the ScriptX EBNF grammar

Notation	Meaning
::=	is defined as
|	or
[ expr ]	expr is optional
[ expr ]*	repeat expr zero or more times
[ expr ]+	repeat expr one or more times

This document is part of the ScriptX Language Guide, one of the volumes of the ScriptX Technical Reference Series. ScriptX is developed by the ScriptX Engineering Team at Apple Computer, successor to the Kaleida Engineering Team at Kaleida Labs, Inc.

Copyright 1996 Apple Computer, Inc. All Rights Reserved.