> On 1 Mar 2019, at 17:08, Petr Fischer via Pharo-users
> <pharo-users@lists.pharo.org> wrote:
>
>
> From: Petr Fischer <petr.fisc...@me.com>
> Subject: Symbol equality method #= - weird condition in the Pharo sourcecode
> Date: 1 March 2019 at 17:08:03 GMT+1
> To: pharo-users@lists.pharo.org
>
>
> Hello, this is Symbol equality method in Pharo:
>
> 1: = aSymbol
> 2: "Compare the receiver and aSymbol."
> 3: self == aSymbol ifTrue: [^ true].
> 4: self class == aSymbol class ifTrue: [^ false].
> 5: "Use String comparison otherwise"
> 6: ^ super = aSymbol
>
> Look at line 4 - what does it mean? That's wrong, isn't it?
>
> Typically, every symbol comparisons end up in line 3, but if you do some work
> with forward proxies for example, condition on line 3 is "false" and then
> weird things on line 4 happens.
>
> If line 4 and further are correct, can someone explain a little?
>
> Thanks! pf
Yes, that looks weird. Line 4 should probably be removed, unless I am missing
something.
Symbols are by definition always #== so in that sense, #= should not even be
implemented (as #= on Object is defined as #==), but since its direct super
class String already overwrote #=, it has to follow.
The super call in line 6 is what allows Symbols and String to be compared.
I would say line 4 is a kind of sanity check, but probably not needed.
