18 lines
476 B
Factor
18 lines
476 B
Factor
! Copyright (C) 2008 Doug Coleman.
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! See http://factorcode.org/license.txt for BSD license.
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USING: checksums classes.singleton kernel math math.ranges
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math.vectors sequences ;
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IN: checksums.adler-32
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SINGLETON: adler-32
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CONSTANT: adler-32-modulus 65521
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M: adler-32 checksum-bytes ( bytes checksum -- value )
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drop
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[ sum 1 + ]
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[ [ dup length [1,b] <reversed> v. ] [ length ] bi + ] bi
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[ adler-32-modulus mod ] bi@ 16 shift bitor ;
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INSTANCE: adler-32 checksum
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