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<DIV dir=ltr align=left><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=149222307-21022007><</SPAN>Alejandro Martínez<SPAN
class=149222307-21022007>></SPAN></FONT></FONT></FONT></DIV>
<DIV></DIV>
<DIV>Hello. I'm trying to figure out how to port a #newSignal message send from
a VisualWorks application (something like Object informationSignal newSignal) to
Squeak, which lacks of Signal class. Does anybody know how to do it or have a
guideline for this? <BR><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007></</SPAN>Alejandro Martínez<SPAN
class=149222307-21022007>></SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007>InformationSignal is simply a subclass of Exception.
</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007>The message #newSignal simply answers a new instance of
an Exception--typically, an instance of the receiver, which would usually be
some subclass of Exception.</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007>The messages and class names result from the fact that
Exceptions in VW were originally instance based, not class based. If I
remember correctly, it was VisualWorks 1.0 (1990) that introduced Exceptions
(instance based) to Smalltalk, not just to the ParcPlace branch of
Smalltalk. Personally, I find the instance-based implementation to be more
elegant. I strongly dislike any design approach that results in an
explosion of different classes, none of which have behavior that significantly
differs from that of its cousins. The upside of the class-based approach
is simply that it makes file-in/file-out of shared globals so easy. But I see
that as a problem with the infrastructure for managing globals, shared pools and
namespaces, and not as a good reason to use classes as heavyweight
globals.</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT size=2><FONT color=#0000ff><FONT face=Arial><SPAN
class=149222307-21022007>--Alan</SPAN></FONT></FONT></FONT></DIV></BODY></HTML>