Module StepByStep {
	Function PermutationStep {
		a=array([])
		c1=lambda (&f, a) ->{
			=car(a)
			f=true
		}
		m=len(a)
		c=c1
		while m>1
			c1=lambda c2=c, p, m=(,) (&f, a) ->{
				if len(m)=0 then m=a
				=cons(car(m),c2(&f, cdr(m)))
				if f then
					f=false
					p++
					m=cons(cdr(m), car(m))
					if p=len(m) then
						p=0
						m=(,)
						f=true
					end if
				end if
			}
			c=c1
			m--
		end while
		=lambda c, a (&f) -> {
			=c(&f, a)
		}
	}
	display(PermutationStep(1,2,3,4))
	display(PermutationStep(100,200,300))
	display(PermutationStep("A", "B", "C", "D"))
	display(PermutationStep("DOG", "CAT", "BAT"))
	
	sub display(S as lambda)
		k=false
		while not k : Print S(&k)#str$(): end while
	end sub
}
StepByStep