On Sep 30, 2008, at 1:34 PM, nicolas cellier wrote:
Mark Volkmann a écrit :
I asked this earlier, but it wasn't the first question in my email,
so it may have been overlooked.
In Smalltalk lingo is it correct to say "signal" and "handle" in
place of Java's "throw" and "catch"?
---
Mark Volkmann
He, nobody answering, seems you reached some kind of quota ;)
I would say, you mostly get it, but:
- in java/C++ etc... throw/catch try/catch are part of Syntax
- in Smalltalk, these are just ordinary messages sent to objects...
As such, you'll see some differences across dialects like #raise
instead of #signal for example...
Inside a Smalltalk dialect, you'll see also some variations (browse
usage of #signal: in Squeak for example).
Concerning #handle, i don't know where you get the information...
#handle:do: is a compatibility message dating from very old
Visualworks image and is not in Squeak images, AFAIK.
ANSI recommend using #on:do:
Also browse usage of simpler messages like #ensure: #ifCurtailed:
Also browse all possible handling actions like #reject #pass #retry
#return #retryWith: #return: #resignalAs:
Maybe you'll need some good tutorial to learn the differences
between these actions (remember that Smalltalk can handle the
MethodContext call stack, so don't be amazed of rich possibilities
there).
Thanks! I think I understand all you said except for two things.
1) The ifCurtailed method. From just looking at the comment in the
method and the code, I have no idea what it does.
2) The reject method. Which class are you referring to? The ones I see
that contain that method don't seem related to exception handling.
---
Mark Volkmann
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