public static bool SystemPairCons(out object answer, object acode, object car, object cdr)
{
//TC typeCode = (TC) (int) acode; // for debugging porpoises
switch ((TC) acode) {
case TC.ACCESS:
answer = Access.Make (car, (Symbol) cdr);
break;
case TC.ASSIGNMENT:
answer = Assignment.Make (car, cdr);
break;
case TC.COMBINATION_1:
answer = Combination1.Make (car, cdr);
break;
case TC.COMMENT:
answer = Comment.Make (car, cdr);
break;
case TC.COMPLEX:
answer = new Complex (car, cdr);
break;
case TC.DEFINITION:
answer = Definition.Make ((Symbol)car, cdr);
break;
case TC.DELAY:
answer = new Delay (car, cdr);
break;
case TC.DISJUNCTION:
answer = Disjunction.Make (car, cdr);
break;
case TC.ENTITY:
answer = new Entity (car, cdr);
break;
case TC.LAMBDA:
// passed in backwards.
object [] names = (object []) cdr;
object [] formals = new object [names.Length - 1];
Array.Copy (names, 1, formals, 0, formals.Length);
SCode body = SCode.EnsureSCode (car);
answer = Lambda.Make (names[0], formals, car);
break;
case TC.PCOMB1:
answer = PrimitiveCombination1.Make ((Primitive1) car, cdr);
break;
case TC.PROCEDURE:
// Lambda had better be a `StandardLambda' because we are
// constructing an closureEnvironment that needs to be first-class.
Environment env = Environment.ToEnvironment (cdr);
Lambda ulam = (Lambda) car;
Lambda plam = (Lambda) ulam.PartialEval (PartialEnvironment.Make((ITopLevelEnvironment) env)).Residual;
StandardLambda slam = (StandardLambda) new StandardLambda (plam.Name,
plam.Formals,
plam.Body,
ulam.FreeVariables,
plam.StaticMapping
);
answer = new StandardClosure (slam, env);
break;
case TC.RATNUM:
answer = new Ratnum (car, cdr);
break;
case TC.SCODE_QUOTE:
answer = Quotation.Make (car);
break;
case TC.SEQUENCE_2:
answer = Sequence2.Make (car, cdr);
break;
case TC.UNINTERNED_SYMBOL:
// What gives? Uninterned strings are squirrely on the CLR.
// We put them in a class object to have more control.
answer = Symbol.MakeUninterned (new String ((char []) car));
break;
case TC.WEAK_CONS:
answer = new WeakCons (car, cdr);
break;
default:
throw new NotImplementedException ();
}
return false;
}
public override bool EvalStep(out object answer, ref Control expression, ref Environment environment)
{
#if DEBUG
Warm ("StandardLambda.EvalStep");
#endif
this.closeCount += 1;
answer = new StandardClosure (this, environment);
return false;
}