Editing Generator (computer programming) (section)

===Tcl===

In [[Tcl]] 8.6, the generator mechanism is founded on named [[coroutine]]s.

<syntaxhighlight lang="tcl">
proc generator {body} {
    coroutine gen[incr ::disambiguator] apply {{script} {
        # Produce the result of [generator], the name of the generator
        yield [info coroutine]
        # Do the generation
        eval $script
        # Finish the loop of the caller using a 'break' exception
        return -code break
    }} $body
}

# Use a simple 'for' loop to do the actual generation
set count [generator {
    for {set i 10} {$i <= 20} {incr i} {
        yield $i
    }
}]

# Pull values from the generator until it is exhausted
while 1 {
    puts [$count]
}
</syntaxhighlight>