--- In concatenative@yahoogroups.com, "icpdesign"
<taoufik.dachraoui@w...> wrote:

> DEFINE
> dig == [] swap 1 - [cons] times # pop nth element and push on top
> dip;
> peek == [] swap 1 - [cons] times # read nth element and push
> swap dup [swap] dip swap dip; # on top
>
> # input at iteration 1: [] [P] [S1 S2 ... Sn]
> # input at iteration i : [Ri-1 ... R1] [P] [Si ... Sn]
> nmap == [null]
> [pop pop]
> [uncons # [Ri-1 ... R1] [P] Si [Si+1 ... Sn]
> 2 dig # [Ri-1 ... R1] [P] [Si+1 ... Sn] Si
> 3 peek infra # [Ri-1 ... R1] [P] [Si+1 ... Sn] Si

[P]

> infra
> 4 dig # [P] [Si+1 ... Sn] Ri [Ri-1 ... R1]
> cons # [P] [Si+1 ... Sn] [Ri Ri-1 ... R1]
> 3 dig # [Si+1 ... Sn] [Ri Ri-1 ... R1] [P]
> 3 dig # [Ri Ri-1 ... R1] [P] [Si+1 ... Sn]
> nmap]
> ifte;
> # input at iteration 1: [] [P] [S1 S2 ... Sn]
> # input at iteration i : [Ri-1 ... R1] [P] [Si ... Sn]
> omap == [null]
> [pop pop]
> [uncons # [Ri-1 ... R1] [P] Si [Si+1 ... Sn]
> 3 dig # [Ri-1 ... R1] Si [Si+1 ... Sn] [P]
> 4 dig # Si [Si+1 ... Sn] [P] [Ri-1 ... R1]
> [] cons cons cons cons # [Si [Si+1 ... Sn] [P] [Ri-1
> ... R1]]
> [stack] dip # [T] [Si [Si+1 ... Sn] [P] [Ri-1 ...

R1]]

> uncons uncons
> uncons uncons # [T] Si [Si+1 ... Sn] [P] [Ri-1 ...
> R1] []
> pop # [T] Si [Si+1 ... Sn] [P] [Ri-1 ... R1]
> 4 dig 5 dig # [Si+1 ... Sn] [P] [Ri-1 ... R1] Si

[T]

> cons # [Si+1 ... Sn] [P] [Ri-1 ... R1] [Si T]
> 3 peek # [Si+1 ... Sn] [P] [Ri-1 ... R1] [Si T] [P]
> infra # [Si+1 ... Sn] [P] [Ri-1 ... R1] [Ri ...]
> uncons pop # [Si+1 ... Sn] [P] [Ri-1 ... R1] Ri
> 2 dig # [Si+1 ... Sn] [P] Ri [Ri-1 ... R1]
> cons # [Si+1 ... Sn] [P] [Ri Ri-1 ... R1]
> 2 dig 3 dig # [Ri Ri-1 ... R1] [P] [Si+1 ... Sn]
> omap]
> ifte;
>
> newmap == [] 2 dig 3 dig nmap reverse;
> oldmap == [] 2 dig 3 dig omap reverse;
> END.
>
> I did not find a primitive reverse in Joy; so i have to
> find a defintion for reverse (when i have more time).
>
> newmap and oldmap use the following Joy primitives: pop cons
> uncons swap dup dip times infra null ifte.
>

Just a correction:

newmap uses: pop null uncons cons dup infra ifte dig peek

oldmap (map) uses: pop null uncons cons dup
infra ifte dig peek stack

> As we can see from the definitions newmap is simpler than oldmap;
> can we do better, in the sense of using the minimum number of
> primitives
>
> I would like to define the maximum (all) number of Joy primitives
> using
> dig peek cons pop i and few other combinators; the less the better.
>
> Kind regards
> Taoufik Dachraoui

defining newmap and oldmap (map) in Joy

icpdesign — 2005-09-28 20:05:43

icpdesign — 2005-09-29 08:02:21