ΜOpal

Eine simple Programmiersprache zu der in der Lehrveranstaltung PSS ein Compiler geschrieben wird. MOpal steht für "Mikro-Opal", was wiederum "kleines Opal" bedeuten soll.

Beispielprogramm:

DEF fac(X:nat):nat ==
  IF eq(X,0) THEN
    1
  ELSE
    mul(X, fac(sub(X, 1)))
  FI

DEF MAIN:nat ==
  fac(8)

EBNF:

Prog -> Def Def* "#"
Def  -> "DEF" Lhs "==" Expr
Lhs  -> "MAIN" ":" Type
      | "id" "(" [ "id" ":" Type ( "," "id" ":" Type )* ] ")" ":" Type
Type -> "nat"
      | "bool"
Expr -> "number"
      | "true"
      | "false"
      | "id" [ "(" [ Expr ( "," Expr )* ] ")" ]
      | "IF" Expr "THEN" Expr [ "ELSE" Expr ] "FI"