Suppose you have a length-n array x of Uint8's = [1,5,32,7,...] , and you
want to convert this
to a long string of hex digits (two per x[i]). The code
y = reduce(string, [hex(xi,2) for xi in x])
==> "01052007..."
will do the trick. (Or, you could use map_reduce or one of the fold
operations.)
But I would like this operation to run in linear time.
Would any of the reduce, map_reduce, or fold operations run in linear time?
With a strict abstract implementation, each intermediate result string
would need to
be created, and each such intermediate result string is immutable, so the
running
time would be Theta(n^2).
Or is the compiler smart about this case? (A small experiment suggests
not.)
Perhaps the right approach is:
x2 = [ hex(xi,2) for xi in x]
y = string(x2)
??
Cheers,
Ron
