factor/library/math/math-combinators.factor

77 lines
2.6 KiB
Factor

! :folding=indent:collapseFolds=1:
! $Id$
!
! Copyright (C) 2003, 2004 Slava Pestov.
!
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions are met:
!
! 1. Redistributions of source code must retain the above copyright notice,
! this list of conditions and the following disclaimer.
!
! 2. Redistributions in binary form must reproduce the above copyright notice,
! this list of conditions and the following disclaimer in the documentation
! and/or other materials provided with the distribution.
!
! THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
! INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
! DEVELOPERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
! SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
! OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
! WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
! OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
! ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
IN: math
USE: kernel
: times ( n quot -- )
#! Evaluate a quotation n times.
#!
#! In order to compile, the code must produce as many values
#! as it consumes.
tuck >r dup 0 <= [ r> 3drop ] [ pred slip r> times ] ifte ;
inline
: (times) ( limit n quot -- )
pick pick <= [
3drop
] [
rot pick succ pick 3slip (times)
] ifte ; inline
: times* ( n quot -- )
#! Evaluate a quotation n times, pushing the index at each
#! iteration. The index ranges from 0 to n-1.
#!
#! In order to compile, the code must consume one more value
#! than it produces.
0 swap (times) ; inline
: 2times-succ ( #{ a b } #{ c d } -- z )
#! Lexicographically add #{ 0 1 } to a complex number.
#! If d + 1 == b, return #{ c+1 0 }. Otherwise, #{ c d+1 }.
2dup imaginary succ swap imaginary = [
nip real succ
] [
nip >rect succ rect>
] ifte ;
: 2times<= ( #{ a b } #{ c d } -- ? )
swap real swap real <= ;
: (2times) ( limit n quot -- )
pick pick 2times<= [
3drop
] [
rot pick dupd 2times-succ pick 3slip (2times)
] ifte ;
: 2times* ( #{ w h } quot -- )
#! Apply a quotation to each pair of complex numbers
#! #{ a b } such that a < w, b < h.
0 swap (2times) ;