NAME
    swap - swap values of two variables

SYNOPSIS
    swap(x,y)

TYPES
    x, y        lvalues, any type

    return      null value

DESCRIPTION
   swap(x,y) assigns the value of x to a temporary location, temp say,
   assigns the value of x to y, and then assigns the value at temp to y.

   swap(x,y) should not be used if the current value of one of the
   variables is a component of the value of the other; for example, after:

         A = list(1,2,3); swap(A, A[[1]]);

   A will have the value 2, but a three-member list remains in memory
   with no method within calc of recalling the list or freeing the
   memory used.

EXAMPLE
   ; x = 3/4; y = "abc"; print x, y, swap(x,y), x, y
   0.75 abc  abc 0.75

   ; A = list(1,2,3); mat B[3] = {4,5,6}; swap(A[[1]], B[1]); print A[[1]], B[1]
   5 2

LIMITS
    none

LINK LIBRARY
    none

SEE ALSO
    assign

## Copyright (C) 1999,2021  Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL.  You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
##
## Under source code control:   1995/12/18 12:34:58
## File existed as early as:    1995
##
## chongo <was here> /\oo/\     http://www.isthe.com/chongo/
## Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
