private static GmState StepUnwind(GmInstruction.Unwind _, GmState state)
{
var head = state.Stack.Peek();
var headNode = state.Heap[head];
return(headNode switch
{
GmNode.Number num => UnwindNum(num, state),
GmNode.Application ap => UnwindAp(ap, state),
GmNode.Global global => UnwindGlobal(global, state),
GmNode.Indirection ind => UnwindInd(ind, state),
_ => throw new ArgumentOutOfRangeException(nameof(headNode))
});
private static GmState Step(GmState state)
{
var(instruction, newState) = state.DequeueInstruction();
return(instruction switch
{
GmInstruction.PushGlobal pushGlobal => StepPushGlobal(pushGlobal, newState),
GmInstruction.PushInt pushInt => StepPushInt(pushInt, newState),
GmInstruction.MkAp mkAp => StepMkAp(mkAp, newState),
GmInstruction.Push push => StepPush(push, newState),
GmInstruction.Update update => StepUpdate(update, newState),
GmInstruction.Pop pop => StepPop(pop, newState),
GmInstruction.Slide slide => StepSlide(slide, newState),
GmInstruction.Alloc alloc => StepAlloc(alloc, newState),
GmInstruction.Unwind unwind => StepUnwind(unwind, newState),
GmInstruction.Eval eval => StepEval(eval, newState),
GmInstruction.Prim prim => StepPrim(prim, newState),
GmInstruction.Cond cond => StepCond(cond, newState),
_ => throw new ArgumentOutOfRangeException(nameof(instruction))
});