Re: subview/sublist/substring

[alex-s168]

All collections (CString, SmartString, Umbra, Vector, List) should support one of these operations:

# Creates a new collection by copying all the data in the range from the old collection
let .sublist(self: t, begin: USize, len: USize): t

# dest needs to have `.push(t,x):t` (like `Vector<x>`)
let .copy-range-to(self: t, begin: USize, len: USize, dest: d): d

I see that there is a [:] operator. Maybe that could be used for this.

This should also be added to the standard library:

let .copy-range-to(self: t, begin: USize, len: USize, dest: d): d= (
   let i = 0;
   while i < len {
      let x = self[i + begin];
      dest = dest.push(x);
      i = i + 1;
   };
   dest
);