Re: [Bug-apl] ⎕EC return values are incorrect for user-defined errors

[David B. Lamkins]

Hi Jüergen,

Sorry for the miscommunication.

SVN 306 does fix 2⊃⎕ec. However, 3⊃⎕ec is still incorrect.

3⊃⎕ec should be the same as what ⎕em would have been without ⎕ec in the
case where ⎕ec traps an error.

Specifically: 3⊃⎕ec should be a three-row text array in which line 1 is
the error message (which may be the text provided to a ⎕es), line 2 is
the offending line of code and line 3 is the error caret(s). This is the
same three error-message lines that would have been printed to the APL
session without the ⎕ec.

This behavior is covered elsewhere on page 280 of the IBM Reference. I
apologize for having left the `paragraph 3' reference in my first email.

On Sun, 2014-06-01 at 18:53 +0200, Juergen Sauermann wrote:
> Hi David,
> 
> thanks, fixed in SVN 306.
> 
> /// Jürgen
> 
> 
> On 05/31/2014 07:51 PM, David B. Lamkins wrote:
> > See the IBM Reference, page 280, paragraph 3.
> >
> > When ⎕EC executes an expression that signals a user-defined error, the
> > second and third items of the result should be the same as the
> > expression's ⎕ET (which would be 0 1 in this case) and ⎕EM. GNU APL
> > returns 0 0 and 'User defined error'.
> >
> > Note also that ⎕ET must not be changed by ⎕EC. GNU APL already does this
> > correctly.
> >
> > It's not clear from the IBM Reference whether ⎕EM should also not be
> > changed by ⎕EC. It seems reasonable to assume that *not* changing ⎕EM is
> > the correct behavior; the whole point of ⎕EC is to execute an expression
> > in a controlled manner. If so, GNU APL is already correct in this
> > regard.
> >
> >
> >        ⎕es 'foo'
> > foo
> >        ⎕ES 'foo'
> >        ^
> >        ⎕em
> > foo
> >        ⎕ES 'foo'
> >        ^
> >        ⎕et
> > 0 1
> >        ⎕ec '⎕es ''foo'''
> >   0  0 0  User defined error
> >        ⎕em
> >
> >
> >
> >
> >
> >
>