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\ calculate factorial by creating a stack of all numbers between n and
\ 1, then multiply every element of that stack together.
\
\ this uses only tail-position call/if, so the call stack never grows
\ past the initial function call.
\
\ this is not meant to be efficient, just exercise parts of the system
\ and be something nice to look at with blinken
: count-to ( n -- n n-1 ... 1 )
dup
1 > if
dup 1 - count-to
then
;
: stack-mul ( n-x ... n x -- v )
dup
1 > if
rot rot * swap 1 - stack-mul
else
drop
then
;
5 count-to
5 stack-mul
drop
|
