The capitalisation of a variable name changes the behaviour of an operator - that's not pretty! It's also not documented in the guide:
::= Creates slot, creates setter, assigns value
:= Creates slot, assigns value
= Assigns value to slot if it exists, otherwise raises exception
These operators are compiled to normal messages whose methods can be overridden. For example:
source compiles to
a ::= 1 newSlot("a", 1)
a := 1 setSlot("a", 1)
a = 1 updateSlot("a", 1)
Luckilly ::= doesn't seem to have the same issue so I'll use that instead (don't really want a getter/setter as it is a constant but it'll do). Cheers,
ChrisM
--- In
iolanguage@..., Jeremy Tregunna <jeremy.tregunna@...> wrote:
>
>
> On 17-Jun-09, at 8:29 AM, joh_90uk wrote:
>
> > Steve, I see rather strange behaviour when using caps for a variable
> > name. See below:
> >
> > Io> 55 type
> > ==> Number
> > Io> aa:=55
> > ==> 55
> > Io> 55 type
> > ==> Number
> > Io> AA:=55
> > ==> 55
> > Io> 55 type
> > ==> AA
> >
> > So by using a caps slot name during a slot assignment, the type of
> > the subject of that assignment is changed to the name of the slot.
> > Not sure why this is happening but I'm guessing it was not intended.
>
> You will see why if you run the following two code snippets:
>
> message(aa := 55) asString
>
> and
>
> message(AA := 55) asString
>
> This was a special case created a couple of years ago to avoid manual
> setting of the type slot. But this is desired behaviour I suppose.
>
> Regards,
>
> Jeremy Tregunna
> jeremy.tregunna@...
>
