

                                                                     expand

    FUNCTION
EXPAND BOOLS ITEMS &optional (DEFAULT NIL)                       [Function]

    Package
    series

    DESCRIPTION

EXPAND is a quasi-inverse of CHOOSE.  The output contains the elements of
the input series ITEMS spread out into the positions specified by the
non-null elements in BOOLS---that is, ITEMS[j] is in the position occupied
by the jth non-null element in BOOLS.  The other positions in the output
are occupied by DEFAULT.  The output stops as soon as BOOLS runs out of
elements or a non-null element in BOOLS is encountered for which there is
no corresponding element in ITEMS.

(EXPAND #Z(NIL T NIL T T) #Z(A B C)) => #Z(NIL A NIL B C) 
(EXPAND #Z(NIL T NIL T T) #Z(A)) => #Z(NIL A NIL)


     SEE ALSO
     about-series
     about-generators
     choose

;Copyright 1989 by the Massachusetts Institute of Technology,
;Cambridge, Massachusetts.

;Permission to use, copy, modify, and distribute this software and its
;documentation for any purpose and without fee is hereby granted,
;provided that this copyright and permission notice appear in all
;copies and supporting documentation, and that the name of M.I.T. not
;be used in advertising or publicity pertaining to distribution of the
;software without specific, written prior permission. M.I.T. makes no
;representations about the suitability of this software for any
;purpose.  It is provided "as is" without express or implied warranty.

;    M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
;    ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
;    M.I.T. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
;    ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
;    WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
;    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
;    SOFTWARE.



