24 lines
668 B
Factor
24 lines
668 B
Factor
! Copyright (C) 2009 Daniel Ehrenberg
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! See http://factorcode.org/license.txt for BSD license.
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USING: sequences kernel math accessors sequences.private ;
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IN: math.bits
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TUPLE: bits { number read-only } { length read-only } ;
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C: <bits> bits
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: check-negative-bits ( n -- n )
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dup 0 < [ non-negative-integer-expected ] when ; inline
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: make-bits ( number -- bits )
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check-negative-bits
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[ T{ bits f 0 0 } ] [ dup abs log2 1 + <bits> ] if-zero ; inline
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M: bits length length>> ; inline
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M: bits nth-unsafe number>> swap bit? ; inline
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INSTANCE: bits immutable-sequence
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: bits>number ( seq -- number )
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<reversed> 0 [ [ 1 shift ] dip [ 1 + ] when ] reduce ;
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