From bug-octave-request at bevo dot che dot wisc dot edu  Fri Jan 28 04:17:45 2000
Subject: Some problems
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Hagen Gilsing <gilsing at informatik dot hu-berlin dot de>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Fri, 28 Jan 2000 04:18:05 -0600 (CST)

On 20-Feb-1999, Hagen Gilsing <gilsing at informatik dot hu-berlin dot de> wrote:

| Description 3:
| -------------
| 
| a)
| octave-2.1.12:1> clear;OCTAVE_VERSION
| OCTAVE_VERSION = 2.1.12
| ans = 2.1.12
| octave-2.1.12:2> try
| >   try error('generate error at level2');
| >   catch error('catched error at level2'); end_try_catch;
| > catch fprintf(2,'catched error at level 1\n'); end_try_catch
| error: catched error at level2
| error: Segmentation fault -- stopping myself...
| attempting to save variables to `octave-core'...
| save to `octave-core' complete
| Segmentation fault
| ../Octave990219 01:58:00 502 #
| 
| b)
| octave-2.1.12:1> clear;OCTAVE_VERSION
| OCTAVE_VERSION = 2.1.12
| ans = 2.1.12
| octave-2.1.12:2> try
| >   try x=y;
| >   catch 0='abc'; end_try_catch;
| > catch fprintf(2,'catched error at level 1\n'); end_try_catch
| error: invalid lvalue function called in expression
| error: evaluating assignment expression near line 4, column 10
| error: Segmentation fault -- stopping myself...
| attempting to save variables to `octave-core'...
| save to `octave-core' complete
| Segmentation fault
| ../Octave990219 02:01:47 502 #
| 
| c)
| octave-2.1.12:1> clear;OCTAVE_VERSION
| OCTAVE_VERSION = 2.1.12
| ans = 2.1.12
| octave-2.1.12:2> function co=f(a,b)
| > try co=[ a b ];catch co=0;error('interrupt in function');end_try_catch;
| > endfunction
| octave-2.1.12:3> try f(zeros(2),ones(3)) catch error("catched interrupt !");end_try_catch
| error: interrupt in function
| error: called from `f'
| error: Segmentation fault -- stopping myself...
| attempting to save variables to `octave-core'...
| save to `octave-core' complete
| Segmentation fault
| ../Octave990219 02:08:04 502 # 
| 
| d)
| I would describe the three cases as problems of nested try-catch-blocks.
| If one would like to work with a hierarchy of try-catch-blocks, one 
| exceptional state in any catching branch terminates the whole program.
| So nearly it is better to only use the try-catch-blocks, if one is sure,

I think I've fixed these problems in the current development sources.

Thanks,

jwe



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