On Thursday, 15 January 2015 at 13:01:50 UTC, Nordlöw wrote:
I want a variant of commonPrefix(a, b) at
http://dlang.org/phobos/std_algorithm.html#commonPrefix
that only counts returns the length of commonPrefix(a, b)
Is commonPrefix lazy enough to make
commonPrefix(a, b).count
as fast as
zip(a, b).count!(ab => ab[0] == ab[1])
?
I just discovered that zip has StoppingPolicy so why does
auto commonPrefixLength(R...)(R ranges) if (ranges.length == 2)
{
import std.range: zip;
return zip!((a, b) => a[0] != b[1])(ranges);
}
unittest
{
assert(commonPrefixLength([1, 2, 3, 10],
[1, 2, 4, 10]) == 2);
}
error as
algorithm_ex.d(1709,40): Error: template std.range.zip cannot
deduce function from argument types !((a, b) => a[0] !=
b[1])(int[], int[]), candidates are:
std/range/package.d(3247,6):
std.range.zip(Ranges...)(Ranges ranges) if (Ranges.length &&
allSatisfy!(isInputRange, Ranges))
std/range/package.d(3265,6):
std.range.zip(Ranges...)(StoppingPolicy sp, Ranges ranges) if
(Ranges.length && allSatisfy!(isInputRange, Ranges))
algorithm_ex.d(1714,30): Error: template instance
algorithm_ex.commonPrefixLength!(int[], int[]) error instantiating
