|
ActiveTcl User Guide |
|
lrange - Return one or more adjacent elements from a list
lrange list first last
List must be a valid Tcl list. This command will return a
new list consisting of elements first through last,
inclusive. The index values first and last are
interpreted the same as index values for the command string index, supporting simple
index arithmetic and indices relative to the end of the list. If
first is less than zero, it is treated as if it were zero.
If last is greater than or equal to the number of elements
in the list, then it is treated as if it were end. If
first is greater than last then an empty string is
returned. Note: “lrange list first first”
does not always produce the same result as “lindex
list first” (although it often does for simple fields
that are not enclosed in braces); it does, however, produce exactly
the same results as “list [lindex list
first]”
Selecting the first two elements:
% lrange {a b c d e} 0 1
a b
Selecting the last three elements:
% lrange {a b c d e} end-2 end
c d e
Selecting everything except the first and last element:
% lrange {a b c d e} 1 end-1
b c d
Selecting a single element with lrange is not the same as
doing so with lindex:
% set var {some {elements to} select}
some {elements to} select
% lindex $var 1
elements to
% lrange $var 1 1
{elements to}
list, lappend, lindex, linsert, llength, lsearch, lset, lreplace, lsort, string
element, list, range, sublist
Copyright © 1995-1997 Roger E. Critchlow Jr.
Copyright © 1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc. Copyright ©
2001 Kevin B. Kenny <kennykb(at)acm.org>. All rights
reserved.