/*	Syntax for the OEJ6510-assembler by Oyvind Jergan 1997
 *
 *	- {a, b, c} indicates set
 *	- U indicates union of sets
 *	- [a b c ...] indicates sequence of symbols a b c ...
 *	- All symbols can be separated by white caracters
 *	- Only words starting with capital letters are domains
 */

Program		=	[Line Line ... Line]

Line            =	EOF
		|       EOL
		|	[; Comment EOL]
		|	[/ * Comment * / Line]
		|	[# Assdir Line]
		|	[Variable Line]
		|	[Variable: Line]
		|	[Variable = Exp Line]
		|	[* = Exp Line]
		|	[Instr Instr-mode Line]
		|	[Data Line]

Comment		=	String
Variable	=	String

Assdir		=	[set Setting]
		|	[option Option]

Setting		=	s_loadaddress		; default is the clc of the first byte in file 

Option		=	o_use_pet_ascii		; use pet_ascii instead of ascii   
		|	o_casesens		; case-sensitive variable-match
		|	o_show_var_def		; show variables as they are defined		|	o_show_var_ref		; list variables with number of references
		|	o_show_var_ref		; list variables with number of references
		|	o_show_instr_ref	; list instructions with number of references
		|	o_show_instr_all	; list all legal instructions (with number of r.)
		|	o_show_output		; show the output from assembler
		|	o_show_errorline        ; show the line where an error occurs
		|	o_show_1_e_on_line      ; show only one error at each line
						; for all options: 1 = true, 0 = false (default false)

Instr-mode	=	EOL			; implied
		|	a			; accumulator
		|	[# Exp]			; immidiate
		|	Exp			; zeropage | absolute | relative
		|	[Exp , x]		; zeropage,x | absolute,x
		|	[Exp , y]		; zeropage,y | absolute,y
		|	[( Exp )]   		; indirect
		|	[( Exp , x )] 		; indirect,x
		|	[( Exp ) , y] 		; indirect,y

Data            |	[.bytes Exp]            ; assemble Exp number of .byte 0
		|	[.byte Exp ... Exp]	; 0 < Exp < 256
		|	[.word Exp ... Exp]	; 0 < Exp < 65536
		|	[.text " Ascii ... Ascii "]

Exp		=	Decnr
		|	Hexnr
		|	Binnr
		|	[" Ascii "]
		|	[+ Exp]
		|	[- Exp]
		|	[Exp + Exp]
		|	[Exp - Exp]
		|	[Exp * Exp]
		|	[Exp / Exp] 
		|	[ < Exp]		; lowbyte
		|	[ > Exp]		; highbyte	
		|	*			; current location pointer
		|	[( Exp )]

Decnr		=	[Ds ... Ds]
Hexnr		=	[$ Hs ... Hs]
Binnr		=	[% Bs ... Bs]
String		=	[Al Ds ... Ds]

Ds member of DS	=	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
Hs member of HS	=	DS U { a, b, c, d, e, f, A, B, C, D, E, F}
Bs member of BS	=	{0, 1}
Al member of AL =	{a, b, ..., z} U {A, B, ..., Z} U {_}
Ascii member of		{ascii caracters}

EOL		=	Cr			; $0a

EOF		=	EndOfFile		; last byte of source read 
White		=	Space
		|	Tab
		|	Linefeed		; $0d