Re: [Amforth] New forth interaction script

[Matthias T. <mt...@we...>]

> 
> Actually, my motivation was a lot simpler.  I wasn't sure if the regular
> expression I use to match an error being indicated by the amforth
> interpreter really covered all cases.  That expression (without the
> delimiting double quotes included below) is:
>   
>    " \?\? -\d+ \d+ \r\n> $"
> 
> Is it correct?

Yes it is.

>  I spent some time looking at the main interpreter trying
> to verify it but I don't read assembly and forth fluently enough yet to
> be sure without investing more time than I had available.

It a bit difficult indeed. The messages get printed by the
words in the prompts.asm file, coordinated in quit.asm.
The first " ?? " comes from PROMPTERROR which prints the
two numbers too. After that quit calls the PROMPTRDY which
generates the line feed and the "> ".

The two numbers are printed using . (DOT) which makes
it possible to get both positive and negative numbers.
The not-so-obvious code in quit makes sure, that the
first number is always negative and the second number
is always positive. (THROW Code resp the value of >IN).

That means that a THROW with a positive code number
does not print anything, THROWs with a negative number
trigger the error prompt as described above. The second
consequence is that the size of the input buffer into
which >IN points should never exceed 32KB.

> If the above regular expression will catch all errors explicitly
> indicated by the interpreter, then I think it would be reasonable to
> change the default behavior to *not* generate an error on output as it
> *will still generate an error* if the error regular expression matches.

As long as nobody changes QUIT and the prompt words, the regex will
work.

>   Matthias> http://amforth.svn.sourceforge.net/viewvc/amforth/trunk/tools/amforth-term.py?view=log
> 
> Wonderful.  I don't really see any need for this to live outside the
> amforth repository, so if I get a chance to make further improvements
> I'll prepare patches against the code there.

Great.

Matthias