On Monday, 2 April 2018 at 18:33:25 UTC, Steven Schveighoffer
wrote:
On 3/30/18 4:45 PM, Cym13 wrote:
On Friday, 30 March 2018 at 20:43:09 UTC, Cym13 wrote:
Hi, I've got the following code that takes a list of files as
argument and xor them together (demo example sufficient for
that discussion).
[...]
Forgot to mention but I'm also quite annoyed at the need for
that ".array" because "transposed" requires the RoR to be
assignable. That kills the laziness. I'm very much open to
suggestions regarding that point.
1. The .save deprecation may not affect you. It's probably
being used by map or fold but may not need to be. Once it's
removed, you may just see the warning go away, and everything
still works just fine. I'm not 100% sure on this, as I don't
know where it's being used.
That's good to hear, although I don't realy like warnings on
which I have no control.
2. The array is necessary, as map is lazy. what you want is a
range of the first byte of each file, then a range of the
second byte of each file, etc. mapping to a byte array can't
possibly do this, because what would happen is that map would
re-open the file, re-read it's contents, and then give you the
*second* byte. This is horribly inefficient.
While I agree that using an array is ugly, and that I want ranges
of first byte (which is why I'm using transposed in the first
place), transposed just doesn't let me work with the result of
map itself. I suppose it's because its signature stipulates
hasAssignableElements. I feel like I'm missing something there
but I can't see what.
But you can probably reduce the memory requirements by
streaming each file's bytes as you need it. Unfortunately, I
don't see a 'byByte' method on File, so you may have to look
elsewhere for that.
-Steve
