silly-joy is an interpreter for the concatenative programming language Joy, implemented in Haskell using extensible-effects.
Here are some resources:
- Mathematical foundations of Joy by Manfred von Thun (archived here, the paper that sparked this project)
- On Wikipedia
- Official page
- Over at http://www.concatenative.org
Simplest way to try it out is by using Docker:
docker run -it rootmos/silly-joy --tui You'll be greeted by a terminal UI with the REPL as well as a window showing the current stack. Very convenient when learning stack-based languages!
> 1 2 + > :stack 3 > 12 * > print 36 > fact := [[pop 0 =] [pop pop 1] [ [dup 1 -] dip dup i *] ifte] dup i > 10 fact > :st 3628800 > ["foo" "bar" strcat] [strlen] b > dup print 6 > 1 swap - print -5 > even := 2 % 0 = > odd := even not > 3 odd 2 even and print true > prime := [dup even [3 <] dip or] [2 =] [prime_trial_division] ifte > prime_trial_division := 3 [[pop % null] [pop =] [[2 +] dip x] ifte] x > [2 3 4 5 6 7 8 9 10 11 12 13] [prime] map print [true true false true false true false false false true false true] > sum := 0 [+] fold > div-3-5 := [dup [3 % null] dip 5 % null or] filter > up-to := pred [[]] [cons] primrec > 10 up-to div-3-5 sum print 23 > next-fib := dup [+] dip swap > add-if-even := [even] [dup [rotate] dip + rotate] [] ifte > 0 1 1 [100 >] [pop pop] [next-fib add-if-even] [i] genrec print 188