Fibonacci numbers in Tcl

Example for versions ActiveTcl 8.5, Tcl 8.5.7

This example uses recursive definition of Fibonacci numbers. Function fib is defined in namespace tcl::mathfunc, so that it can be used as math function in expr expressions. 

proc tcl::mathfunc::fib {n} {
    if {$n<=1} {
        return 1
    } else {
        return [expr fib([expr {$n - 1}]) + fib([expr {$n - 2}])]
    }
}

set s ""
for {set i 0} {$i < 16} {incr i} {
    append s [expr fib($i)] ", "
}
puts "$s..."