[REBOL] Re: On mutability and sameness
From: kenneth:nwinet at: 16-Jun-2001 22:34
Reading my mind again Joel,
> > a: [1:30]
> > b: [1:30]
> > same? a b ;==false
>
> ...this outcome is easy to predict. Notice that A and B
> are both blocks, with EQUAL? content, but since they were
> constructed separately, they are not the SAME? block.
>
> > same? do a do b ;==true
>
> Remember that when DO is given a block, it evaluates all
> expressions in the block, and returns the value of the last
> expression as its result. Given that fact:
>
> >> do a == 1:30
> >> do b == 1:30
> >> same? do a do b == true
>
> The result value from DO A is the TIME! value of 1:30, and
> likewise for DO B . Since TIME! is not a reference type,
> any occurrence of 1:30 is the same as any other occurrence
> of 1:30. Therefore, any expression that produces a TIME!
> value of 1:30 yields a result that is SAME? to the result of
> any other expression yielding 1:30, even something like:
>
> >> 0:30 * 3 == 1:30
> >> same? do a 0:30 * 3 == true
> >> same? 2:00 - 0:30 0:30 * 3 == true
I just finished doing a bunch of tests like this (I honored to be in such
esteem company! ;-))
ken.
