NAME

       lreplace - Replace elements in a list with new elements

SYNOPSIS

       lreplace list first last ?element element ...?
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DESCRIPTION

       lreplace returns a new list formed by replacing zero or more elements of list with the element arguments.
       first  and  last  are  index  values specifying the first and last elements of the range to replace.  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.  0 refers to the first
       element of the list, and end refers to the last element of the list.

       If either first or last is less than zero, it is considered to refer to before the first element  of  the
       list.  This  allows  lreplace  to prepend elements to list.  If either first or last indicates a position 2
       greater than the index of the last element of the list, it is treated as if it is an  index  one  greater 2
       than the last element. This allows lreplace to append elements to list.

       If last is less than first, then any specified elements will be inserted into the list before the element
       specified by first with no elements being deleted.

       The  element  arguments  specify zero or more new elements to be added to the list in place of those that
       were deleted.  Each element argument will become a separate element of the list.  If no element arguments
       are specified, then the elements between first and last are simply deleted.

EXAMPLES

       Replacing an element of a list with another:

              % lreplace {a b c d e} 1 1 foo
              a foo c d e

       Replacing two elements of a list with three:

              % lreplace {a b c d e} 1 2 three more elements
              a three more elements d e

       Deleting the last element from a list in a variable:

              % set var {a b c d e}
              a b c d e
              % set var [lreplace $var end end]
              a b c d

       A procedure to delete a given element from a list:

              proc lremove {listVariable value} {
                  upvar 1 $listVariable var
                  set idx [lsearch -exact $var $value]
                  set var [lreplace $var $idx $idx]
              }

       Appending elements to the list; note that end+2 will initially be treated as if it is 6  here,  but  both 2
       that and 12345 are greater than the index of the final item so they behave identically:                   2

              % set var {a b c d e}                                                                              2
              a b c d e                                                                                          2
              % set var [lreplace $var 12345 end+2 f g h i]                                                      2
              a b c d e f g h i                                                                                  2

SEE ALSO

       list(3tcl),   lappend(3tcl),   lindex(3tcl),  linsert(3tcl),  llength(3tcl),  lsearch(3tcl),  lset(3tcl),
       lrange(3tcl), lsort(3tcl), string(3tcl)

KEYWORDS

       element, list, replace

Tcl                                                    7.4                                        lreplace(3tcl)