On 01/22/2015 11:26 AM, ddos wrote:
> i want to create 100 uniform distributed numbers and print them
> my first attempt, just written by intuition:
> [0 .. 100].map!(v => uniform(0.0, 1.0).writeln);
>
> i found out i can't write [0 .. 100] to define a simple number range,
As currently being discussed in another thread, the a..b syntax does not
correspond to a first-class D language construct.
> but is there a function to do so?
Yes, std.range.iota:
auto numbers = iota(100).map!(_ => uniform(0.0, 1.0));
Note that, 'numbers' is lazy, the definition above does not call
uniform() yet.
To make an array out of it, call std.array.array at the end:
auto numbers = iota(100).map!(_ => uniform(0.0, 1.0)).array;
> second attempt, replacing the range with an simple array
> [0,1,2].map!(v => uniform(0.0,1.0).writeln);
> this does compile and run, but doesn't print anything, just an empty
> string, why is that?
What I said above: it is just a range waiting to be used.
> finally i got it working with this:
> auto t = [0,1,2].map!(v => uniform(0.0,1.0));
> writeln(t);
>
> seems pretty easy eh?
writeln() consumes any range to print it on the standard output. There
is no array to speak of though: writeln() consumes a copy of 't' and
your 't' is still a lazy range waiting to be consumed.
Ali
