53 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Factor
		
	
	
		
			Executable File
		
	
			
		
		
	
	
			53 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Factor
		
	
	
		
			Executable File
		
	
| ! Copyright (C) 2008 Doug Coleman.
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| ! See http://factorcode.org/license.txt for BSD license.
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| USING: alien.c-types kernel math namespaces sequences
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| io.backend io.binary combinators system vocabs.loader
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| inspector ;
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| IN: random
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| 
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| SYMBOL: insecure-random-generator
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| SYMBOL: secure-random-generator
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| SYMBOL: random-generator
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| 
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| GENERIC: seed-random ( tuple seed -- )
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| GENERIC: random-32* ( tuple -- r )
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| GENERIC: random-bytes* ( n tuple -- byte-array )
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| 
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| M: object random-bytes* ( n tuple -- byte-array )
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|     swap [ drop random-32* ] with map >c-uint-array ;
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| 
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| M: object random-32* ( tuple -- r ) 4 random-bytes* le> ;
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| 
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| ERROR: no-random-number-generator ;
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| 
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| M: no-random-number-generator summary
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|     drop "Random number generator is not defined." ;
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| 
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| M: f random-bytes* ( n obj -- * ) no-random-number-generator ;
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| 
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| M: f random-32* ( obj -- * ) no-random-number-generator ;
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| 
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| : random-bytes ( n -- byte-array )
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|     [
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|         dup 4 rem zero? [ 1+ ] unless
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|         random-generator get random-bytes*
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|     ] keep head ;
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| 
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| : random ( seq -- elt )
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|     dup empty? [
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|         drop f
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|     ] [
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|         [
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|             length dup log2 7 + 8 /i
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|             random-bytes byte-array>bignum swap mod
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|         ] keep nth
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|     ] if ;
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| 
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| : random-bits ( n -- r ) 2^ random ;
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| 
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| : with-random ( tuple quot -- )
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|     random-generator swap with-variable ; inline
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| 
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| : with-secure-random ( quot -- )
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|     >r secure-random-generator get r> with-random ; inline
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