1. Sequence allocation
Simple, if I define a sequence named "s1":
s1 = {1,2,3,4,"whatever..."}
then define another sequence, "s2"
s2 = {s1,"other stuff"}
Will s2 contain a copy of s1 as its first element, or a pointer to s1. I'm using
this kind of example in a test I'm doing. But I don't want to use this approach
if s1 actually gets *replicated* into the first element of s2, as a lot of space
will get wasted if there are a lot of s2 like sequences lurking around! :)
If anyone with a clue more than myself can tell me it'd be much appreciated
Cheers
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2. Re: Sequence allocation
On Fri, 21 Jul 2000 00:45:10 +1200, F Dowling <dobehe at EUDORAMAIL.COM> wrote:
>Simple, if I define a sequence named "s1":
>
>s1 = {1,2,3,4,"whatever..."}
>
>then define another sequence, "s2"
>
>s2 = {s1,"other stuff"}
>
> Will s2 contain a copy of s1 as its first element, or a pointer to s1.
> I'm using this kind of example in a test I'm doing. But I don't want
> to use this approach if s1 actually gets *replicated* into the first
> element of s2, as a lot of space will get wasted if there are a lot
> of s2 like sequences lurking around! :)
AFAIK, the answer is the latter; the pointer is copied. This changes it if
you change any of the elements of s1 or s2[1]; A copy must be made at that
time.
To go one level deeper though:
Since s1[5] is a sequence, only the _pointer_ to that sequence would
need to be copied (providing that isn't the element you change), so you
won't have lots of "whatever..."s floating around either.
Euphoria is a very, very clever language when it comes to things like this.
HTH,
Carl
3. Sequence allocation
Oops!
In my previous post
the line s2=s1&{4,5,6} should read s2={s1,4,5,6} and the following line
should be s2[4]=0
In the I cited, s1 is not being inserted into a sequence, its elements are,
and since they are integers, they will be copied. My origianl example would
still be workable if the elements of s1 were not integers.
By the way, I forgot to add in my previous post that this integers and
pointers representation of sequences is the reason that Euphoria is limited
to 31-bit integers in a 32-bit environment: one bit is used as a flag to
indicate a pointer.
-- Mike Nelson
