[REBOL] Re: Sameness - a pragmatic approach.
From: lmecir:mbox:vol:cz at: 12-Feb-2003 6:37
Hi Joel,
> I must be missing something. The question of why ALIASes "must" be
> immutable isn't answered by the fact that they currently are. That
> only begs the question again, "But *WHY* are they, and would it
> break something crucial if that were changed?"
>
> -jn-
I am sure, that in the current implementation it would break things. Let's
suppose, that you use both the word 'a and the word 'aaa. In the current
implementation you create two new words, each of which has got its own
storage
. A block like:
block: [a aaa]
then contains two such normal words. Next, suppose, that you want to do:
alias 'a "aaa"
, which is "forbidden". If it were allowed, you would be able to create a
new block
new-block: [a aaa]
The trouble is, that although both BLOCK and NEW-BLOCK look and feel the
same, they contain different 'aaa words: the former 'aaa has its own
storage
, while the second one hasn't, because it uses the storage of 'a.
The implementation can be changed, but at the expense of an interpreter
slow-down and a "retroactivity", which would change the behaviour of BLOCK.
Regards
-L
