Re: Re(2): [colorforth] abort

[Mark Slicker <maslicke@xxxxxxxxxxx>]

On Fri, 13 Jun 2003, Samuel Falvo wrote:

> > 1) Closed, data controlled environments such as industrial process control,
> > standalone development systems or anywhere that the computer generates all
> > data such as in colorForth.
> >
> > 2) Open, external communication based systems like DOS, linux, Windows and
> > the
> > ill-fated iTV project.
>
> In both cases, you must be able to handle errors that can crop up.  The
> so-called closed environments that you speak of are not truely closed: they
> ultimately still depend on the programmer or user to accept their initial data
> sets.
>
> For example, while working in XcolorForth, it is a fairly common occurance for
> it to outright crash if I edit any block beneath 18.  I really can't imagine
> why: the editor should never actually change anything unless I tell it to.  I
> think it's a good bet that it doesn't change this region of memory.  Yet, it
> still crashes, leaving the fault point somewhere in the editor itself.  It's
> probably encountering a color token it never expected to see.

No, its not the editor, but the graphics. XcolorForth uses a buffer
provided by SDL, and is much more sensitive to drawing outside the buffer.
The clipping of colorForth is not precise, so too much text will crash the
editor. Holding a key down in the interpreter, letting the stack go off
the bottom of the screen demonstrates this. It might be good project for
someone to make XcolorForth bullet proof. There is only a couple things
really. The other I noticed is pressing certain keys (not in 27-key set) will
cause a crash.

>
> Even on a normal source block, you can advance the cursor beyond the end of the
> block's last word.  The cursor disappears, leaving me without any knowledge of
> where it actually is.  If you go too far, it will probably crash too.  I don't
> know because I haven't tried it.

Nope, this won't happen. Make the cursor disapear, and type a word. The
word and cursor will apear at the end of the block. The cursor has a state
independent of block, so the cursor will apear at the same word location
in each block.

Mark


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