Richard Suchenwirth 2007-05-08 - The functionality of
take is to retrieve the value from a variable, which is then
unset. This is very simple, as you'll immediately see, but can be useful - I needed it for the global textvariable of a dialog. As the variable was named like the dialog window, which in turn had a name constructed with
clock clicks, the global variables causes pollution of ::. By using
take when returning the result, the variable is now immediately unset.
proc take _var {
upvar 1 $_var var
return [set var][unset var]
}
NEM take is also the name of a function in
Haskell (and possibly other
Functional Programming languages) that returns the first
n elements in a list:
proc take {n xs} { lrange $xs 0 [incr n -1] }
MJ - Or in 8.5:
proc take {n xs} { lrange $xs 0 $n-1 }