We have high-level functions defined in Seq, Map, Set, ... etc.

In 90%. it's quite simple translations, so (after looking on Iterable) can be a good starting point for contribution.

In that regard, the crate currently only supports:

#[with]
let ... = <call>?...?

as well as:

#[with]
let ... = match <call> { ... }
// rest *after* match (same scope)

which unsugar(s) to:

with_<call>(..., |__anon__| {
    let ... = match __anon__ { ... };
    // rest *after* match (same scope)
})

But it would be really nice i