• Saaa (11/11) Sep 17 2009 I understand a bitarray being faster than a boolean array as the first u...
• BCS (4/9) Sep 17 2009 Because you can't slice a bit array the same way you can slice a int or ...
• Saaa (1/11) Sep 18 2009
• BCS (7/22) Sep 18 2009 Could you /please/ include the "reply to" line in the text of your posts...
• Saaa (3/3) Sep 18 2009 BCS,
• BCS (2/4) Sep 19 2009 thanks

"Saaa" <empty needmail.com> writes:

I understand a bitarray being faster than a boolean array as the first uses 
bitwise (hardware) operators.
Is this a correct understanding of the situation?
Why then is a boolean array not implemented in that way?
I expect there to be a good reason which I just don't know.

I'd like to be able to bit shift and test a large (1024) array of bits as 
fast as possible (runs thousands of times per iteration).
Should I go with the bitarray (I don't see the shift and test functions) or 
create my own bitarray somehow using intrinsics?
I'd rather use existing implementations, but if the speed is a factor off or 
something.. 

BCS <none anon.com> writes:

Hello Saaa,

 I understand a bitarray being faster than a boolean array as the first
 uses
 bitwise (hardware) operators.
 Is this a correct understanding of the situation?
 Why then is a boolean array not implemented in that way?

Because you can't slice a bit array the same way you can slice a int or byte 
array. D used to have a bit type and bit arrays where primitives but it made 
for all kinds of problems when you wanted to do slices.

"Saaa" <empty needmail.com> writes:

Ah, slicing, of course, thanks!


 Hello Saaa,

 I understand a bitarray being faster than a boolean array as the first
 uses
 bitwise (hardware) operators.
 Is this a correct understanding of the situation?
 Why then is a boolean array not implemented in that way?

 Because you can't slice a bit array the same way you can slice a int or 
 byte array. D used to have a bit type and bit arrays where primitives but 
 it made for all kinds of problems when you wanted to do slices.

 

BCS <none anon.com> writes:

Could you /please/ include the "reply to" line in the text of your posts. 
Most clients seem to add it by default and it makes it much easier for people 
to find replies to there posts. (I have a filter set up to mark post with 
my username so, in my case I'd guess that without that line, I'm about 3-5 
times more likely to not see a reply.)

BTW the following line is the "reply to" line:

Hello Saaa,

 Ah, slicing, of course, thanks!
 
 Hello Saaa,
 
 I understand a bitarray being faster than a boolean array as the
 first
 uses
 bitwise (hardware) operators.
 Is this a correct understanding of the situation?
 Why then is a boolean array not implemented in that way?

 Because you can't slice a bit array the same way you can slice a int
 or byte array. D used to have a bit type and bit arrays where
 primitives but it made for all kinds of problems when you wanted to
 do slices.
 

"Saaa" <empty needmail.com> writes:

BCS,

Thanks for pointing that out.
I'll keep to that convention in my next posts. 

BCS <none anon.com> writes:

Hello Saaa,

 BCS,

 I'll keep to that convention in my next posts.

thanks