pga/parser.mly

%{
  open Lexing
  open Types
%}

(* tokens *)
%token SEMICOL EXCLAM PLUS MINUS OMEGA LPAREN RPAREN HASH
%token <int> NUMBER
%token <char> UPPER LOWER
%token EOF

(* start symbol *)
%type <Types.program> program
%start program

%%

program:
  | instrs=separated_list(SEMICOL, instruction) EOF
  { instrs }

instruction:
  | c=LOWER                { Basic c }
  | EXCLAM                 { Terminate }
  | PLUS c=LOWER           { Ptest c }
  | MINUS c=LOWER          { Ntest c }
  | HASH n=NUMBER          { Jump n }
  | i=instruction n=NUMBER { Repeat (i, n) }
  | i=instruction OMEGA    { Loop i }
  | c=UPPER                { Program c }
  | LPAREN i=separated_list(SEMICOL, instruction) RPAREN { Concat i }