4 ms·

Turnstyle – An esoteric, graphical functional language

141 points by JNRowe 2y ago

rosshays 2y ago
Worth maybe calling out that there is a few academic language implementations using this name (turnstile, turnstile+) https://docs.racket-lang.org/turnstile https://docs.racket-lang.org/turnstile. It's not a standalone language but worth pointing out
- lolinder 2y ago
  This is an esolang and that's an academic language. I'm pretty sure neither one cares to optimize for searchability.
dacapoday 2y ago
Is it similar to https://github.com/mxgmn/MarkovJunior https://github.com/mxgmn/MarkovJunior
- oneearedrabbit 2y ago
  While both MJ and Turnstyle are Turing-complete, Turnstyle shares more similarities with Piet (mentioned by the author), Wireworld, and, of course, Conway's Game of Life.
- smusamashah 2y ago
  I didn't understand the language but the examples look amazing. Are there any others like that? Edit: Another one is Cellpond https://cellpond.cool/ https://cellpond.cool/ https://github.com/TodePond/CellPond https://github.com/TodePond/CellPond
drdeca 2y ago
This seems cool, but I’m having difficulty understanding the specification. It would be nice if there were some examples of e.g. 2+3 , (lambda f. lambda x. (f (f x)))(lambda y. (y+2)) 3 ?
- lifthrasiir 2y ago
  `2 + 3` would be internally `((prim(3, 1) 2) 3)`, which can be composed of following fragments (where `^>v<` indicates the direction and the position of the current turnstile): AA prim(3, 1): >BBB C literal 2: AvB CC literal 3: AvB CCC A (prim(3,1) 2): >*****prim(3,1) * * 2 A ((prim(3,1) 2) 3): >*****(prim(3,1) 2) * * 3 So assuming that each distinct letter corresponds to a distinct color, one possible encoding would be: A A BB >>BBBBBCCCCCD B C AD B C D CBD DCA AAA BB The specification allows for a simple "identity" pattern which can be used to extend otherwise overlapping patterns here. The following, if I did everything right, would be more compact but much harder to decipher: CADABB >>BBCD CBDCAD AAABBD
lifthrasiir 2y ago
I'm a bit confused about what really is being interpreted here, because my reading of the specification indicates that the entire image is read as a single expression in the lambda calculus but the graphic interpreter looks like a procedural execution at the first glance. Is it just a visualization of beta-reduction in progress? EDIT: I think I got it and I think calling this as an "encoding" is a misnomer. The program starts with a single term `turnstyle(x, y, dir)` which gets lazily evaluated to the actual term. So not only the evaluation might be lazy, but the parsing is also lazy and this is a key point of this esolang which should be highlighted more in my opinion.

141 points by JNRowe 2y ago

Worth maybe calling out that there is a few academic language implementations using this name (turnstile, turnstile+) https://docs.racket-lang.org/turnstile https://docs.racket-lang.org/turnstile. It's not a standalone language but worth pointing out

lolinder 2y ago
This is an esolang and that's an academic language. I'm pretty sure neither one cares to optimize for searchability.

dacapoday 2y ago

Is it similar to https://github.com/mxgmn/MarkovJunior https://github.com/mxgmn/MarkovJunior

oneearedrabbit 2y ago
While both MJ and Turnstyle are Turing-complete, Turnstyle shares more similarities with Piet (mentioned by the author), Wireworld, and, of course, Conway's Game of Life.
smusamashah 2y ago
I didn't understand the language but the examples look amazing. Are there any others like that? Edit: Another one is Cellpond https://cellpond.cool/ https://cellpond.cool/ https://github.com/TodePond/CellPond https://github.com/TodePond/CellPond

drdeca 2y ago

This seems cool, but I’m having difficulty understanding the specification. It would be nice if there were some examples of e.g. 2+3 , (lambda f. lambda x. (f (f x)))(lambda y. (y+2)) 3 ?

lifthrasiir 2y ago
`2 + 3` would be internally `((prim(3, 1) 2) 3)`, which can be composed of following fragments (where `^>v<` indicates the direction and the position of the current turnstile): AA prim(3, 1): >BBB C literal 2: AvB CC literal 3: AvB CCC A (prim(3,1) 2): >*****prim(3,1) * * 2 A ((prim(3,1) 2) 3): >*****(prim(3,1) 2) * * 3 So assuming that each distinct letter corresponds to a distinct color, one possible encoding would be: A A BB >>BBBBBCCCCCD B C AD B C D CBD DCA AAA BB The specification allows for a simple "identity" pattern which can be used to extend otherwise overlapping patterns here. The following, if I did everything right, would be more compact but much harder to decipher: CADABB >>BBCD CBDCAD AAABBD

lifthrasiir 2y ago

I'm a bit confused about what really is being interpreted here, because my reading of the specification indicates that the entire image is read as a single expression in the lambda calculus but the graphic interpreter looks like a procedural execution at the first glance. Is it just a visualization of beta-reduction in progress? EDIT: I think I got it and I think calling this as an "encoding" is a misnomer. The program starts with a single term `turnstyle(x, y, dir)` which gets lazily evaluated to the actual term. So not only the evaluation might be lazy, but the parsing is also lazy and this is a key point of this esolang which should be highlighted more in my opinion.