Initialize a field of a struct using another field of the same struct [duplicate]

Answer 1

How can I do it?

You can't. Unless I misunderstand your question, this is the same problem as this one. Structs generally cannot have references into themselves.

Answer 2

I think you're making things overly complicated. Splitting a string at specific chars can be done with:

let s: String = "Tiger in the snow".into();
for e in s.split(|c| c == 'e') {
    println!("{}", e);
}

Output:

Tig
r in th
 snow

There are several variations of the split function to suit various needs.