Hi Ladislav,

On Sunday, September 1, 2002, 8:28:22 PM, you wrote:

LM> It looks to me, that the "first class error" and the "legal vs. illegal
LM> error" distinction are two sides of the same coin.

Indeed.  We  cannot  use  errors  at  all,  only  disarm them. So,
probably  we  can  state  that  errors can never be "legal", if we
decide that we should never intentionally return an (armed) error.

(It can be seen as a sort of workaround...)

LM> Your IS-REALLY-ERROR? function works for simple code like above, but, AFAIK,
LM> we cannot handle all possible cases, like e.g.:

The  problem is that if you enclose the code in a block or a paren
the  error  is  immediately  fired; i.e. the only way to return an
error  from  an expression is if the expression is being evaluated
directly  as  an argument for a function. This makes me think that
it's  likely  that  this was added as a way to make functions like
DISARM  and  ERROR? work, but otherwise error!s were intended as a
very special class of values.

I   am   more   and   more   tempted  to  start  writing  a  REBOL
implementation, just to try out different approaches and to better
understand  why  things  have  been  done this way... pity I don't
really have the time to do it.

Regards,
   Gabriele.
-- 
Gabriele Santilli <[EMAIL PROTECTED]>  --  REBOL Programmer
Amigan -- AGI L'Aquila -- REB: http://web.tiscali.it/rebol/index.r

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