Re: Executing code without generating stack machine code

himanshu.garg@gmail.com wrote:
> Hello,
>
> I have seen hoc ( Kernighan & Pike ), PL0 ( Niklaus Wirth )
that
> are calculator programs.
>
> I was wondering if I could execute code from its tree
> representation without generating any intermediate code. At the least
> my language supports if/then/else, loops, procedures, goto's and
> expressions. This would allow me to avoid the extra stack machine
> processor code, required to run the intermediate code.


Simple interpreting of trees is not hard, but you might find it more
fun to try something like a threaded code interpreter, which can be
added to an AST quite easily by replacing the object type with a
pointer to the procedure which implements that object type. (I'm sure
C++ programmers will have a pretty way to do it, but it all boils down
to procedure pointers)


I wrote an example some years ago, which might help:
http://www.gtoal.com/software/ThreadedCode


regards


Graham

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