[Newbies] About true

[nicolas cellier]

You mustn't create new instances of true/false/nil because the sole instance 
of these class is known by the VM which use them for ifTrue:/ifFalse test 
(with a test like ==).
Smalltalk is an open system, but there you reached the limits due to VM 
optimizations.

For curiosity, i tried the expression with other dialects, VW and gst both 
fail with mustBeBoolean error (True basicNew is neither recognized as a 
Boolean), and stx does forbid use of basicNew on True. The latter protection 
is maybe the right behavior.

Nicolas

Le Jeudi 03 Août 2006 20:54, Mathieu a écrit :
> Hi,
>
> I was playing with true:
>
> Supposes you inspect 'True basicNew'. It return a new instance of True
> but the following don't work:
>
> True basicNew ifTrue:[true]
>
> Strange?
>
> I have try to debug it and it fail on basicNew ??
>
> I have inspect a CompiledMethod with this code and I saw:
>
> 21 <41> pushLit: True
> 22 <D0> send: basicNew
> 23 <98> jumpFalse: 25
> 24 <79> return: true
> 25 <78> returnSelf
>
> That seems to be correct but at run time it don't do this ??
> How come?
>
> Thx
>
> Math
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