On Wednesday, 3 February 2016 at 16:39:26 UTC, Andrei
Alexandrescu wrote:
On 02/01/2016 03:46 AM, Dragos Carp wrote:
On Friday, 29 January 2016 at 20:40:18 UTC, Andrei
Alexandrescu wrote:
That'd be interesting if (a) lazy and (b) general a la
https://dlang.org/library/std/range/recurrence.html. -- Andrei
To be clear, by general you mean to allow functions with more
than 2
arguments?
My ambitions were lower :o). I was thinking of supporting any
operation, not only summation.
Good that I asked. Contrary to "reduce", "recurrence" works also
with functions with more than 2 arguments, so I saw it as a hint
in this direction.
For example if you have:
foo(int i, int j, int k) { return i + j + k; }
then:
scan!foo([1, 2, 3, 4]).array returns [1, 2, 6, 12]
Is "scan" (thanks Timon) telling enough? The python
"accumulate"
conflicts with the C++ meaning.
That's a sliding window of compile-time-known size, which is
interesting on its own. There are several ways to handle the
limits, each useful in certain situations. I don't get where 12
comes from in your example.
I calculated Yn = fct(Yn-2, Yn-1, Xn) thus Y3 = 2 + 6 + 4 == 12
I will prepare a PR for the binary function implementation.
