! :folding=indent:collapseFolds=0:

! $Id$
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! Copyright (C) 2003, 2004 Slava Pestov.
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IN: math
USE: kernel

: integer? dup fixnum? swap bignum? or ;
: rational? dup integer? swap ratio? or ;
: real? dup number? swap complex? not and ;

: max ( x y -- z )
    2dup > [ drop ] [ nip ] ifte ;

: min ( x y -- z )
    2dup < [ drop ] [ nip ] ifte ;

: between? ( x min max -- ? )
    #! Push if min <= x <= max. Handles case where min > max
    #! by swapping them.
    2dup > [ swap ] when  >r dupd max r> min = ;

: sq dup * ; inline

: pred 1 - ; inline
: succ 1 + ; inline

: neg 0 swap - ; inline
: recip 1 swap / ; inline

: rem ( x y -- x%y )
    #! Like modulus, but always gives a positive result.
    [ mod ] keep  over 0 < [ + ] [ drop ] ifte ;

: sgn ( n -- -1/0/1 )
    #! Push the sign of a real number.
    dup 0 = [ drop 0 ] [ 1 < -1 1 ? ] ifte ;