Array-based process expansion insufficiently documented

https://gitlab.redox-os.org/redox-os/ion/blob/master/manual/src/expansions/02-process.md#process-expansions states:

an array-based process expansion will split the output into an array delimited by whitespaces.

...
let array = @(cmd args...)

NOTES:

...

• @(cmd) is equivalent to @split($(cmd))

But in a test directory containing files aa, bb, and cc, doing

let res=@(ls)
echo @res[0]

gives

while doing

echo @split($(ls))[0]

gives

aa