/* e.g.

  overlay <- ScreenOverlay
  bounds <- rightScreenBounds
  overlay bounds bounds
  overlay show
*/
  
sclass GazelleV_LeftArrowScript > SimpleLeftToRightParser {
  interface Evaluable {
    public O get(VarContext ctx default new);
  }
  
  // We're using SynchronizedList as a list wrapper
  //sclass Script extends ArrayList<Evaluable> {
  sclass Script extends SynchronizedList<Evaluable> is Evaluable {
    *() { super(new L); }
    
    public O get(VarContext ctx) {
      O result = null;
      for (step : this)
        result = step.get(ctx);
      ret result;
    }
    
    toString { ret pnlToLines(this); }
  }
  
  srecord noeq Assignment(S var, Evaluable expression) is Evaluable {
    public O get(VarContext ctx) {
      O o = expression.get(ctx);
      ctx.set(var, o);
      ret o;
    }
    
    toString { ret var + " <- " + expression; }
  }
  
  srecord noeq NewObject(Class c) is Evaluable {
    public O get(VarContext ctx) {
      ret callConstructor(c);
    }
    
    toString { ret "new " + className(c); }
  }
  
  srecord noeq GetVar(S var) is Evaluable {
    public O get(VarContext ctx) {
      ret ctx.get(var);
    }
    
    toString { ret var; }
  }
  
  srecord noeq Const(O value) is Evaluable {
    public O get(VarContext ctx) {
      ret strOrClassName(value);
    }
    
    toString { ret value; }
  }
  
  srecord CallMethod(Evaluable target, S methodName, L<Evaluable> args) is Evaluable {
    public O get(VarContext ctx) {
      ret call(target.get(ctx), methodName, mapToArray(args, arg -> arg.get(ctx)));
    }
    
    toString { ret target + "." + formatFunctionCall(methodName, args); }
  }
}