On 18/12/2010 08:52, spir wrote:
On Fri, 17 Dec 2010 02:42:14 -0500
bearophile<[email protected]> wrote:
http://www.reddit.com/r/programming/comments/enajl/purity_in_d_language/
Bye,
bearophile
I take the opportunity to question the def of weakly pure.
-1- How can this even compile?
pure append (ref int[] a, int i) {a ~= i;}
The _only_ task of this func is to change state.
It is best not to think of D's pure as saying the function is pure in
the traditional sense (side-effect free), but rather to say the
side-effects are confined to the function's parameters only (and the
state/data that is transitively reachable from them).
The key benefit of this is that it allows the *caller* of such pure
function to determine which subset of state/data *may* change by a call
to such function.
--
Bruno Medeiros - Software Engineer
