justinNEE has asked for the wisdom of the Perl Monks concerning the following question:

Hello, I need a data structure that can hold 64 bits of info so I can do & and | and other fun stuff to it... but my build of perl/operating system/processor doesn't support this kind of thing... right? Whats the best way to do this?

Edit kudra, 2002-02-26 Changed title

  • Comment on Need data struct that can hold 64 bits of info (was: bitboards in perl)

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Re: bitboards in perl
by blakem (Monsignor) on Feb 24, 2002 at 06:04 UTC
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Re: bitboards in perl
by YuckFoo (Abbot) on Feb 24, 2002 at 16:23 UTC
    You can also use strings of any length. See perlman:perlop, refer to section 'Bitwise String Operators'. Not as effecient as vectors and probably slower, but 'easier'.

    YuckFoo

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Re: bitboards in perl
by justinNEE (Monk) on Feb 24, 2002 at 15:57 UTC
    perlfunc on vec() : "BITS therefore specifies the number of bits that are reserved for each element in the bit vector. This must be a power of two from 1 to 32 (or 64, if your platform supports that). " I guess I could just use two 32 bit elements and make my own bitwise operators...
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      ...reserved for each element in the bit vector.

      You were wanting 64 bits, so each is one bit wide. This is 32-bit perl:

      $ perl -e 'vec( $foo, 63, 1) = 1; print unpack( "b64",$foo),$/'
0000000000000000000000000000000000000000000000000000000000000001

      [download]
      or, if you prefer your high order bits printed on the left,
      $ perl -e 'vec( $foo, 63, 1) = 1; print scalar reverse(unpack "b64",$f
+oo),$/'
1000000000000000000000000000000000000000000000000000000000000000

      [download]
      The bitwise operators work on vec() strings

      After Compline,
      Zaxo

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