19 lines
492 B
Factor
19 lines
492 B
Factor
! Copyright (C) 2005, 2008 Slava Pestov, Daniel Ehrenberg.
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! See http://factorcode.org/license.txt for BSD license.
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USING: sequences kernel accessors ;
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IN: columns
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! A column of a matrix
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TUPLE: column seq col ;
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C: <column> column
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M: column virtual-seq seq>> ;
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M: column virtual@ [ col>> swap ] [ seq>> ] bi nth bounds-check ;
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M: column length seq>> length ;
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INSTANCE: column virtual-sequence
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: <flipped> ( seq -- seq' )
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dup empty? [ dup first length [ <column> ] with map ] unless ;
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