Built in function library

We are considering to add commonly used functions as built-in.
What functions would you like to see?
For example, MD5hash, random number generator and so on.

Please fix the “third function call” error at last. For example, we have a function:

:local myFunc do {:log info "Hello world !"}

If we call it with the shell twice in a row, it will be executed three times!

[$myFunc]
[$myFunc]

Hello world !
Hello world !
Hello world !


If we make a call without a wrapper , this error does not occur:

$myFunc
$myFunc

Hello world !
Hello world !

If the function is called to perform :put, there will be gaps:

http://forum.mikrotik.com/t/frequent-empty-variables-in-scripts-turned-out-to-be-bug/168049/1

Interestingly, subsequent calls after the second are processed normally:

[$myFunc]
[$myFunc]
[$myFunc]

Hello world !
Hello world !
Hello world !
Hello world !