When called on an immutable seq, suffix! doesn't throw the correct error

[LeoMehraban]

I'd expect the code

IN: scratchpad { } "a" suffix!

to throw an immutable error. Instead, it throws a sequence out of bounds error:

T{ bounds-error { index 0 } { seq { } } }

I've tested this for arrays and strings, so it's probably all immutable sequences that are effected

[mrjbq7]

Well, it's not an immutable sequence:

IN: scratchpad { } immutable? .
f

[mrjbq7]

Perhaps you're thinking we need like a not-growable? mixin?

[LeoMehraban]

Wait, arrays are mutable? I thought the whole difference between arrays and vectors are that vectors are mutable and arrays aren't

[LeoMehraban]

Either way, an out of bounds error isn't very helpful in this context

[mrjbq7]

Immutable means the contents can’t be changed.

Message ID: @.***>

[mrjbq7]

What error seems more appropriate?

It’s saying that it can’t set a value at index 0.

[mrjbq7]

Vectors are growable and arrays are not.