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by James Robertson.
Original Post: The power of Smalltalk
Feed Title: Cincom Smalltalk Blog - Smalltalk with Rants
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Feed Description: James Robertson comments on Cincom Smalltalk, the Smalltalk development community, and IT trends and issues in general.
Brad Abrams quotes Chris Brumme on why you don't get a lot of info from a NullReferenceException (sounds like trying to send a message to nil in Smalltalk):
The NullReferenceException occurs because an instruction like call [eax 44] or mov edx, [esi 24] has resulted in an access violation. %A0We don't retain nearly enough information to form a correspondence between a particular register being NULL at a particular EIP and the fact that a particular reference in the application was null. %A0Especially since the EIP might be in a shared helper like a write barrier routine or an array helper. %A0In those cases, we would have to perform a limited stack walk to get the effective EIP.
The machinery that would be required to improve this error message is huge. %A0For the foreseeable future, you will have to rely on debuggers, or on FX code explicitly checking and throwing an appropriate NullArgumentException.
Fascinating. Contrast that with what I get when someone reports a BottomFeeder bug to me - I get a complete stack trace - with information on every object involved (arguments, senders, receivers - the works). All available in the runtime, dropped to a log file that can be sent to me. And that doesn't begin to explain how much better the information is in the development environment. This is one of those supposedly nebulous things about Smalltalk productivity - just about everything is simpler and easier to get to
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