I'm just getting back into Smalltalk after 10 years, so pardon if I'm 
bringing up something that may seem obvious to you.

This code:

a := 'squeak'.
'squeak' at: 6 put: $l.

causes the value of a to change to 'squeal'.  I understand how this is
happening (there is only one instance of a string literal in squeak, as
with symbols; I don't think this is true of all Smalltalks, but I could be
wrong), but I don't understand why it was designed this way. It just seems
kind of odd to me.

Perhaps it's usually not a problem? I do notice that:

a := 'squeak'.
b := 'squeal'.
a at: 6 put: $l.
a == b

returns false.

Nontheless, it kind of spooked me to learn that if an instance variable
received its value from a string literal (e.g. via an accessor or in
initialization) that the value of that variable could change if someone
typed something like 'string' at: 1 put: $x.

Any comments?

Thanks!

Jen