On 5/15/14, 9:03 AM, Timon Gehr wrote:
On 05/15/2014 05:24 PM, Andrei Alexandrescu wrote:
On 5/15/14, 3:31 AM, luka8088 wrote:
Yeah, I read all about weak/string purity and I do understand the
background. I was talking about strong purity, maybe I should pointed
that out.
So, to correct myself: As I understood strong purity implies
memoization. Am I correct?
Yes, as long as you don't rely on distinguishing objects by address.
Purity of allocation is frequently assumed by functional languages
Examples?
cons 1 2 is equal to cons 1 2
because without it it would be difficult to get much work done.
Why?
It's rather obvious. You've got to have the ability to create new values
in a pure functional programming language.
Then,
most functional languages make it difficult or impossible to distinguish
values by their address.
If it's not impossible because of lack of the concept it's not a pure
functional language.
Agreed.
In D that's easy. A D programmer needs to be
aware of that, and I think that's fine.
Andrei
It's not fine: The spec claims that this problem does not exist.
We must fix the spec. Please submit a pull request, thanks.
Andrei
