[oinksoft]

I don't know if this is helpful for you, but I map <c-p> to run the open buffer in Vim in the buffer's filetype's interpreter (or compile and run, etc.). For GNU APL, this is:

  nnoremap <buffer> <C-P> :write !cat - <(echo ")OFF") \| apl --script<CR>

It took some time to figure that out, but combined with https://github.com/ngn/vim-apl, it is not too bad of an editing experience.