Different results of slice <string> <from> <to> with too large <to>

[programandala-net]

Why slice "0123" 2 4 and slice "0123" 2 5 give different results?:

$> slice "0123" 2 3
=> 23

$> slice "0123" 2 4
=> 23

$> slice "0123" 2 5
=>

In both cases the third parameter is beyond the last index. Therefore I expected the same result: the final part or the string ("23") or an empty string (which is what slice "0123" 2 5 returns), or null, or even an error.

Is it a bug or am I missing something?

[RickBarretto]

Yes, it's a bug! As you can see, the highest possible index in this case is 3.

Both, 4 and 5 are out-of bound indexes, so this should be illegal.
We have two options to fix that: 1) Raise an exception 2) Clip-it and just consider the possible index (lowest and highest).