(by the author of the Standard ML implementation, MLKit)

Couple of observations:

1. I had to patch the makefile to get it to work; add ‘-e’ to the ‘echo’ command-line that generates version.sml.

2. Seems to be missing a lot of convenience features; e.g. no ⍨, no using floats as shapes

3. Based on the compiler output, it looks like it tries to statically infer rank. So this trivial example messes it up:

$ ./aplt <(echo '⎕←((+/2<?10 10 10 10 10)⍴2)⍴1⋄0')
[Reading file: /proc/self/fd/11]
Op_e(reshape): cannot unify [int]1 and <int>'r0 when trying to unify [int]1 and <int>'r0 in first argument to reshape

(Also, I was able to get it to runtime GC error, but for some reason I can’t reproduce that now.)

4. Looking at tests, d-ops seem to be supported, but strange result from this adverb:

$ ./aplt <(echo 'A←{⍺⍺+⍵}⋄⎕←- A 5 6 7⋄0')
[Reading file: /proc/self/fd/11]
Compile Error: /proc/self/fd/11:1.5.
  Compile Error: /proc/self/fd/11:1.5.
  expects numerical argument arrays

The forced static rank inference is likely to make this implementation unusable for non-trivial code. Prefer a JIT-type approach with guarded rank inference. (Can do the same thing for name classes, incidentally. I tried to trick it thattaways—point ‘4’ above being the fruit of those efforts—but it seems guards or other branching structures are not yet supported.)