include "lib.cd";

package asm;

Asm = <c> OpList.  //EOF.

Opcode: MathOp | MemOp | ControlOp.
      
MathOp: Plus | Minus | Times | Divide
             | Less | Greater | Equal
             | And | Or.
MemOp: Push | Pop | Def | Undef | Load.
ControlOp: Label | Jmp | IfZ.

Less = "less".
Greater = "greater".
Equal = "equal".
And = "and".
Or = "or".

Plus = "plus".
Minus = "minus".
Times = "times".
Divide = "divide".


Push =  "push" *s <i> int.
Pop =   "pop".
Def =   "def".
Undef = "undef".
Load =  "load" *s <i> int.

Label = "label" *s <id> ident.
Jmp =   "jump" *s <id> ident.
IfZ =   "ifzero" *s <id> ident.
IfNZ =  "ifnzero" *s <id> ident.

OpList: OpCons | OpEmpty.
OpCons = *s*s*s*s*s*s*s <first> Opcode *l <rest> OpList.
OpEmpty = .

ExecStack = .

Entry = <label> String <pc> OpList.