div0:
> Objects are defined to have an identity, so by returning a new object
> from the function you are not getting the same result for the same inputs.
> Does D relax the definition of pure to say a function may return an
> equivalent object?
Interesting question, I have tried the following cod
bearophile Wrote:
> Probably there are ways to solve the situation, using unique or something
> else, but I think that way leads to C++-style madness (see the ridiculously
> complex lambdas of the last C++, they look like a joke to me. Those designers
> have missed the point that the essential
div0 Wrote:
> In your example you are returning values types, not objects as in the
> original question.
Arrays are not value types. Substitute int[] x with a pointer, same argument
applies.
-Steve
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Steven Schveighoffer wrote:
> On Thu, 18 Jun 2009 18:16:36 -0400, div0
> wrote:
>
>> Pure functions are not allowed to alter global state.
>> That's what you doing when you create a new object.
>>
>> http://en.wikipedia.org/wiki/Functional_programmin
Steven Schveighoffer:
>
int[] f()
{
int[] x = new int[5];
foreach(i, ref n; x) n = i;
return x;
}
int[] g()
{
int[] x = new int[6];
foreach(i, ref n; x) n = i;
return x;
}
f and g can be pure, because they do not have side effects. However,
consider:
void fill(int[] x
On Thu, 18 Jun 2009 18:16:36 -0400, div0
wrote:
Pure functions are not allowed to alter global state.
That's what you doing when you create a new object.
http://en.wikipedia.org/wiki/Functional_programming
I once thought as you do. You are wrong. Memory allocation is a
necessary funct
Reply to div0,
Pure functions are not allowed to alter global state. That's what you
doing when you create a new object.
http://en.wikipedia.org/wiki/Functional_programming
Based on that, cons makes lisp not functional.
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Jesse Phillips wrote:
> http://stackoverflow.com/questions/1008803/how-to-use-pure-in-d-2-0
>
> class TestPure
> {
> string[] msg;
> void addMsg( string s )
> {
>msg ~= s;
>}
> };
>
> pure TestPure run2()
> {
>TestPure t = new TestPur
http://stackoverflow.com/questions/1008803/how-to-use-pure-in-d-2-0
class TestPure
{
string[] msg;
void addMsg( string s )
{
msg ~= s;
}
};
pure TestPure run2()
{
TestPure t = new TestPure();
t.addMsg("Test");
t.addMsg("this.");
return t;
}
This doesn't work and the answer
