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lreplace(n)                  Tcl Built-In Commands                 lreplace(n)

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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 greater |
       than the index of the last element of the list, it is treated as if it  |
       is an index one greater 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 that and 12345 are greater than    |
       the index of the final item so they behave identically:                 |

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

SEE ALSO
       list(n), lappend(n), lindex(n), linsert(n), llength(n), lsearch(n),
       lset(n), lrange(n), lsort(n), string(n)

KEYWORDS
       element, list, replace

Tcl                                   7.4                          lreplace(n)