Comparing Node.js with Tcl(pietersz.co.uk)

    proc g {} {
        echo $a
    }

    proc f {} {
        set a 10
        g
    }

    f

    can't read "a": no such variable
        while executing
    "echo $a"
        (procedure "g" line 2)
        invoked from within
    "g"
        (procedure "f" line 3)
        invoked from within
    "f"
        (file "main.tcl" line 35)

    (defun g ()
      (message "%s" a))

    (defun f ()
      (let ((a 10))
        (g)))

    (f)