Wait a second, wasn't wisp something else as well? searches for a few seconds
Ah here it is: https://hg.sr.ht/~arnebab/wisp (a fewer parens lisp notation)
and I'm sure I've seen a time travelling debuggable js-transpiled thing long ago
ps: oh and this https://github.com/paulitex/Wisp
pps: ok i'm digressing https://lips.js.org/