87 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			87 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Factor
		
	
	
| ! Copyright (C) 2009 Slava Pestov.
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| ! See http://factorcode.org/license.txt for BSD license.
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| USING: kernel accessors sequences byte-arrays bit-arrays math hints sets ;
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| IN: bit-sets
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| 
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| TUPLE: bit-set { table bit-array read-only } ;
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| 
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| : <bit-set> ( capacity -- bit-set )
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|     <bit-array> bit-set boa ;
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| 
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| INSTANCE: bit-set set
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| 
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| M: bit-set in?
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|     over integer? [ table>> ?nth ] [ 2drop f ] if ; inline
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| 
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| M: bit-set adjoin
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|     ! This is allowed to crash when the elt couldn't go in the set
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|     [ t ] 2dip table>> set-nth ;
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| 
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| M: bit-set delete
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|     ! This isn't allowed to crash if the elt wasn't in the set
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|     over integer? [
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|         table>> 2dup bounds-check? [
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|             [ f ] 2dip set-nth
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|         ] [ 2drop ] if
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|     ] [ 2drop ] if ;
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| 
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| ! If you do binary set operations with a bitset, it's expected
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| ! that the other thing can also be represented as a bitset
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| ! of the same length.
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| <PRIVATE
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| 
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| ERROR: check-bit-set-failed ;
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| 
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| : check-bit-set ( bit-set -- bit-set )
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|     dup bit-set? [ check-bit-set-failed ] unless ; inline
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| 
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| : bit-set-map ( seq1 seq2 quot -- seq )
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|     [ 2drop length>> ]
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|     [
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|         [
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|             [ [ length ] bi@ assert= ]
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|             [ [ underlying>> ] bi@ ] 2bi
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|         ] dip 2map
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|     ] 3bi bit-array boa ; inline
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| 
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| : (bit-set-op) ( set1 set2 -- table1 table2 )
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|     [ set-like ] keep [ table>> ] bi@ ; inline
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| 
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| : bit-set-op ( set1 set2 quot: ( a b -- c ) -- bit-set )
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|     [ (bit-set-op) ] dip bit-set-map bit-set boa ; inline
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| 
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| PRIVATE>
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| 
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| M: bit-set union
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|     [ bitor ] bit-set-op ;
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| 
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| M: bit-set intersect
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|     [ bitand ] bit-set-op ;
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| 
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| M: bit-set diff
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|     [ bitnot bitand ] bit-set-op ;
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| 
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| M: bit-set subset?
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|     [ intersect ] keep = ;
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| 
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| M: bit-set members
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|     [ table>> length iota ] keep [ in? ] curry filter ;
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| 
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| <PRIVATE
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| 
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| : bit-set-like ( set bit-set -- bit-set' )
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|     ! This crashes if there are keys that can't be put in the bit set
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|     over bit-set? [ 2dup [ table>> length ] bi@ = ] [ f ] if
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|     [ drop ] [
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|         [ members ] dip table>> length <bit-set>
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|         [ [ adjoin ] curry each ] keep
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|     ] if ;
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| 
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| PRIVATE>
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| 
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| M: bit-set set-like
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|     bit-set-like check-bit-set ; inline
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| 
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| M: bit-set clone
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|     table>> clone bit-set boa ;
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