[Pharo-project] Fwd: Pharo by Example vol 2: new chapter available
Thanks laurent Stef Begin forwarded message:
From: laurent laffont <laurent.laffont@gmail.com> Date: March 3, 2010 10:09:32 PM GMT+01:00 To: Stéphane Ducasse <stephane.ducasse@inria.fr> Subject: Re: [Pharo-project] Pharo by Example vol 2: new chapter available
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse <stephane.ducasse@inria.fr> wrote: Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
I haven't read the chapter yet, but there is something that bothers me a little about the Exception hierarchy... what I've seen lately is that Exceptions are not used only as exceptions but as a why to get context information (for example Seaside with WACurrentRequestContext), notify about an event (for example the Notification class and subclasses), etc. Despite if it is a good idea to solve this issues with exceptions, calling Exception to the root of the hierarchy makes a lot of noise (at least to me... I mean, a Notification is not an Exception, something you were not expecting... getting the current context has nothing to do with an exception...)... So, have you think about changing the name to that class and making the protocol simpler (at least for the root of the hierarchy) so all these types of uses fit better than they do today? (for example, retrying a notification looks like no sense, the same for wacurrentrequestcontext) I think that the idea of "crawling" on the execution stack or the execution flow have more sense as metaphor to look for another name... Anyway, just a thought. Bye, Hernan. 2010/3/3 Stéphane Ducasse <stephane.ducasse@inria.fr>
Thanks laurent
Stef
Begin forwarded message:
*From: *laurent laffont <laurent.laffont@gmail.com> *Date: *March 3, 2010 10:09:32 PM GMT+01:00 *To: *Stéphane Ducasse <stephane.ducasse@inria.fr> *Subject: **Re: [Pharo-project] Pharo by Example vol 2: new chapter available*
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse < stephane.ducasse@inria.fr> wrote:
Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
hi Hernan, You're very right saying that exception are often abused. In Java, you have a class Throwable. Cheers, Alexandre On 9 Mar 2010, at 08:10, Hernan Wilkinson wrote:
I haven't read the chapter yet, but there is something that bothers me a little about the Exception hierarchy... what I've seen lately is that Exceptions are not used only as exceptions but as a why to get context information (for example Seaside with WACurrentRequestContext), notify about an event (for example the Notification class and subclasses), etc. Despite if it is a good idea to solve this issues with exceptions, calling Exception to the root of the hierarchy makes a lot of noise (at least to me... I mean, a Notification is not an Exception, something you were not expecting... getting the current context has nothing to do with an exception...)... So, have you think about changing the name to that class and making the protocol simpler (at least for the root of the hierarchy) so all these types of uses fit better than they do today? (for example, retrying a notification looks like no sense, the same for wacurrentrequestcontext) I think that the idea of "crawling" on the execution stack or the execution flow have more sense as metaphor to look for another name... Anyway, just a thought. Bye, Hernan.
2010/3/3 Stéphane Ducasse <stephane.ducasse@inria.fr> Thanks laurent
Stef
Begin forwarded message:
From: laurent laffont <laurent.laffont@gmail.com> Date: March 3, 2010 10:09:32 PM GMT+01:00 To: Stéphane Ducasse <stephane.ducasse@inria.fr> Subject: Re: [Pharo-project] Pharo by Example vol 2: new chapter available
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse <stephane.ducasse@inria.fr
wrote: Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
-- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
hey, you are right, I forgot about that in Java. On Tue, Mar 9, 2010 at 8:31 AM, Alexandre Bergel <alexandre@bergel.eu>wrote:
hi Hernan,
You're very right saying that exception are often abused. In Java, you have a class Throwable.
Cheers, Alexandre
On 9 Mar 2010, at 08:10, Hernan Wilkinson wrote:
I haven't read the chapter yet, but there is something that bothers me a
little about the Exception hierarchy... what I've seen lately is that Exceptions are not used only as exceptions but as a why to get context information (for example Seaside with WACurrentRequestContext), notify about an event (for example the Notification class and subclasses), etc. Despite if it is a good idea to solve this issues with exceptions, calling Exception to the root of the hierarchy makes a lot of noise (at least to me... I mean, a Notification is not an Exception, something you were not expecting... getting the current context has nothing to do with an exception...)... So, have you think about changing the name to that class and making the protocol simpler (at least for the root of the hierarchy) so all these types of uses fit better than they do today? (for example, retrying a notification looks like no sense, the same for wacurrentrequestcontext) I think that the idea of "crawling" on the execution stack or the execution flow have more sense as metaphor to look for another name... Anyway, just a thought. Bye, Hernan.
2010/3/3 Stéphane Ducasse <stephane.ducasse@inria.fr> Thanks laurent
Stef
Begin forwarded message:
From: laurent laffont <laurent.laffont@gmail.com>
Date: March 3, 2010 10:09:32 PM GMT+01:00 To: Stéphane Ducasse <stephane.ducasse@inria.fr> Subject: Re: [Pharo-project] Pharo by Example vol 2: new chapter available
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse < stephane.ducasse@inria.fr> wrote: Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
-- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
For me there are much more important things to fix or make better :) Stef
I haven't read the chapter yet, but there is something that bothers me a little about the Exception hierarchy... what I've seen lately is that Exceptions are not used only as exceptions but as a why to get context information (for example Seaside with WACurrentRequestContext), notify about an event (for example the Notification class and subclasses), etc. Despite if it is a good idea to solve this issues with exceptions, calling Exception to the root of the hierarchy makes a lot of noise (at least to me... I mean, a Notification is not an Exception, something you were not expecting... getting the current context has nothing to do with an exception...)... So, have you think about changing the name to that class and making the protocol simpler (at least for the root of the hierarchy) so all these types of uses fit better than they do today? (for example, retrying a notification looks like no sense, the same for wacurrentrequestcontext) I think that the idea of "crawling" on the execution stack or the execution flow have more sense as metaphor to look for another name... Anyway, just a thought. Bye, Hernan.
2010/3/3 Stéphane Ducasse <stephane.ducasse@inria.fr> Thanks laurent
Stef
Begin forwarded message:
From: laurent laffont <laurent.laffont@gmail.com> Date: March 3, 2010 10:09:32 PM GMT+01:00 To: Stéphane Ducasse <stephane.ducasse@inria.fr> Subject: Re: [Pharo-project] Pharo by Example vol 2: new chapter available
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse <stephane.ducasse@inria.fr> wrote: Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
2010/3/9 Hernan Wilkinson <hernan.wilkinson@gmail.com>
I haven't read the chapter yet, but there is something that bothers me a little about the Exception hierarchy... what I've seen lately is that Exceptions are not used only as exceptions but as a why to get context information (for example Seaside with WACurrentRequestContext), notify about an event (for example the Notification class and subclasses), etc. Despite if it is a good idea to solve this issues with exceptions, calling Exception to the root of the hierarchy makes a lot of noise (at least to me... I mean, a Notification is not an Exception, something you were not expecting... getting the current context has nothing to do with an exception...)... So, have you think about changing the name to that class and making the protocol simpler (at least for the root of the hierarchy) so all these types of uses fit better than they do today? (for example, retrying a notification looks like no sense, the same for wacurrentrequestcontext) I think that the idea of "crawling" on the execution stack or the execution flow have more sense as metaphor to look for another name... Anyway, just a thought.
+1.
Bye, Hernan.
2010/3/3 Stéphane Ducasse <stephane.ducasse@inria.fr>
Thanks laurent
Stef
Begin forwarded message:
*From: *laurent laffont <laurent.laffont@gmail.com> *Date: *March 3, 2010 10:09:32 PM GMT+01:00 *To: *Stéphane Ducasse <stephane.ducasse@inria.fr> *Subject: **Re: [Pharo-project] Pharo by Example vol 2: new chapter available*
Some notes:
Page 1: The basic idea behing exception .... I would expect a schema to show the workflow.
Page 8: When an exception is signaled, the exception handling mechanism ....I've read it 3 times (for something finally quite simple), maybe it needs a sequence diagram or reformulation.
Section 1.15: How exceptions are implemented. I had to read several times to understand, lot of informations to handle at once.
Page 27 (bottom): For example, in method 1.1 ... specify "on page 19" or put the snippet again so we can easily compare with method 1.2.
I like the "real code" examples. The "How..." sections too.
When not to use Exceptions: not to "hide errors". I have too many times seen try ... catch ... to hide errors to the users.
Maybe add a "When to use Exceptions" section, reminding the "Crash early" principle.
Laurent Laffont
On Tue, Mar 2, 2010 at 2:26 PM, Stéphane Ducasse < stephane.ducasse@inria.fr> wrote:
Hi guys
We just released a new chapter for Pharo by Example Vol.2 on Exceptions http://pharobyexample.org/
Let us know what you think.
Stef
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
participants (4)
-
Alexandre Bergel -
Hernan Wilkinson -
Mariano Martinez Peck -
Stéphane Ducasse