Re: QUIT and ABORT

On 17/05/2025 9:30 pm, Ruvim wrote:

On 2025-05-17 06:56, dxf wrote:

On 16/05/2025 9:12 pm, Ruvim wrote:

...
What solution do you mean?

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Default behaviour of QUIT is Core QUIT.  THROW handles -56 by jumping to
Core QUIT.

>
If you make `throw` do this regardless of whether a user's exception frame exists in the exception stack, you make the `-56` error code uncatchable. So, the following test case will fail:
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   t{  [: -56 throw ;] catch -> -56 }t
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And what is the benefit?

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Why should it fail?

 
You wrote: "THROW handles -56 by jumping to Core QUIT". Then the test should fail. But as you now show, you only meant the case where there is no user exception frame in the exception stack.
 
 

>
   [: -56 throw ;] catch  ok  -56 <
>
   [: -1 throw ;] catch  ok  -1 <

 
Okay, these cases are compliant.
 
 

>
   1 2 3 -56 throw
     ok  1 2 3 <
>
   1 2 3 -1 throw
     ok

 
This special handling of `-56` is inconsistent, not justified by practice, and complicates implementations.

Neither special nor complicated:

  -1  of s0 @ sp! fs0 @ fsp ! (core-quit) then

  -56 of (core-quit) then
 

Yes, in some scenarios (such as interactive work) you may prefer this behavior, but for *any* uncaught exceptions. So, special handling of `-56` won't help you at all.
>
>
>

  The application programmer then has the option of making QUIT
catchable by defining:
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    : QUIT -56 THROW ;
>

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But this option already exists. There is no need to specially handle `-56` in `throw`.

>
By that argument there's no reason to specially handle -1 in THROW.
>

 
As I already mentioned, there are no special handling, it only specifies error messages:
 
  -1 — the empty message (no message);
  -2 — a program-defined message (from last executed `abort"`);
  any other — an implementation defined message concerning the error conditions.
 
Except for the message text, all actions are the same regardless of the error code.

By 'same action' you mean they all converge at Core QUIT.  Well, the QUIT I'm
discussing does that too.