26 lines
761 B
Factor
26 lines
761 B
Factor
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USING: accessors kernel locals math math.order sequences ;
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IN: tensors.tensor-slice
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TUPLE: step-slice < slice { step integer read-only } ;
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:: <step-slice> ( from to step seq -- step-slice )
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step zero? [ "can't be zero" throw ] when
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seq length :> len
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step 0 > [
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from [ 0 ] unless*
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to [ len ] unless*
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] [
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from [ len ] unless*
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to [ 0 ] unless*
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] if
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[ dup 0 < [ len + ] when 0 len clamp ] bi@
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! FIXME: make this work with steps
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seq dup slice? [ collapse-slice ] when
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step step-slice boa ;
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M: step-slice virtual@
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[ step>> * ] [ from>> + ] [ seq>> ] tri ;
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M: step-slice length
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[ to>> ] [ from>> - ] [ step>> ] tri
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dup 0 < [ [ neg 0 max ] dip neg ] when /mod
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zero? [ 1 + ] unless ;
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