What to use instead of array.join if RHS is not a range?

[bearophile]

Andrej Mitrovic:

> Is there some other function which can join with an
> element as a separator?

This is not efficient, but it's useful to call it inside the 
post-condition of a more efficient version to test the results of 
the faster version:


import std.stdio, std.array;

// 
http://hackage.haskell.org/packages/archive/base/latest/doc/html/src/Data-List.html#intersperse
T[] intersperse(T)(T[] items, T sep) pure nothrow {
     static T[] prependToAll(T[] items, T sep) pure nothrow {
         return items.empty ?
                [] :
                sep ~ (items.front ~ prependToAll(items[1 .. $], 
sep));
     }

     return items.empty ?
            [] :
            items.front ~ prependToAll(items[1 .. $], sep);
}

void main() {
    static struct S { int x; }
    auto arr = [S(2), S(4), S(6)];
    auto s = S(10);
    auto result = arr.intersperse(s);
    writeln(result);
}


Bye,
bearophile