[takeda]

I haven't used Tcl in years, but you are right about strings, actually the goal is that every data type is implicitly marshalled into string and vice versa.

As for the eval you need to keep discipline there is difference whether you use [] {} or "".

The magic about the language is that it has no statements, for example you are missing try/catch? You can implement it your own: http://code.activestate.com/recipes/68396-try-catch-finally/