NAME head - create a list of specified size from the head of a list SYNOPSIS head(x, y) TYPES x list y int return list DESCRIPTION If 0 <= y <= size(x), head(x,y) returns a list of size y whose elements in succession have values x[[0]]. x[[1]], ..., x[[y - 1]]. If y > size(x), head(x,y) is a copy of x. If -size(x) < y < 0, head(x,y) returns a list of size (size(x) + y) whose elements in succession have values x[[0]]. x[[1]], ..., i.e. a copy of x from which the last -y members have been deleted. If y <= -size(x), head(x,y) returns a list with no members. For any integer y, x == join(head(x,y), tail(x,-y)). EXAMPLE ; A = list(2, 3, 5, 7, 11) ; head(A, 2) list (2 members, 2 nonzero): [[0]] = 2 [[1]] = 3 ; head(A, -2) list (3 members, 3 nonzero): [[0]] = 2 [[1]] = 3 [[2]] = 5 LIMITS none LINK LIBRARY none SEE ALSO tail, segment ## Copyright (C) 1999 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: 1995/07/10 02:09:30 ## File existed as early as: 1995 ## ## chongo /\oo/\ http://www.isthe.com/chongo/ ## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/