/*
 *  Gigatron Control Language v1 definition
 *  EBNF in W3C notation
 *  Recommended railroad diagram generator: http://www.bottlecaps.de/rr/ui
 */
Gcl1File    ::= Space* 'gcl1' ((Space|Block) Word?)* Newline
Block       ::= '[' Word? ((Space|Block) Word?)* ']'
Word        ::= Keyword | Prefix? (Name | Number) Operator?
Keyword     ::= 'call' | 'deek' | 'def' | 'do' | 'else' |
                'if' ('<' | '=' | '>' | '<=' | '<>' | '>=') '0' 'loop'?  |
                'loop' | 'peek' | 'pop' | 'push' | 'ret'
Prefix      ::= [<>\%]
Name        ::= Letter (Letter | '_' | Decimal)*
Operator    ::= [-+&|^=.,:;!?^] | '++' | '--' | '<<'
Number      ::= [-+]? (Decimal+ | '$' Hexadecimal+)
Comment     ::= '{' (Space | [#x21-#x7A] | #x7C | #x7E)* '}'
Letter      ::= [a-zA-Z]
Decimal     ::= [0-9]
Hexadecimal ::= [0-9a-fA-F]
Space       ::= #x20 | Newline | Comment
Newline     ::= #x09? #x0A