[squeak-dev] Message>>#= & Message>>#hash

Eliot Miranda eliot.miranda at gmail.com
Tue Nov 20 00:16:51 UTC 2018

Hi David,

On Mon, Nov 19, 2018 at 9:52 AM David T. Lewis <lewis at mail.msen.com> wrote:

> On Mon, Nov 19, 2018 at 09:32:17AM -0800, Eliot Miranda wrote:
> > Hi All,
> >
> >     In VisualWorks Message implements #= & #hash naturally; two messages
> > whose selectors and arguments are #= are also equal.  But in Cuis, Squeak
> > and Pharo Message inherits #= and #hash from Object, i.e. uses identity
> > comparison.  This is, to say the least, annoying.  Any objections to
> > implementing comparing in Message to match VisualWorks?
> >
> That sounds like an obviously good thing to do :-)
> Is the lookupClass instance variable relevant for comparisons? I am
> guessing not, since we already have #analogousCodeTo: for that type of
> comparison.

For me it is relevant.  Two messages with different lookupClasses, e.g. one
with nil and one with a specific class, represent different messages, one a
normal send one a super send.  So my changes in waiting include lookupClass
in both hash and =.  I don't think it makes much difference, but the
incompatibility with VisualWorks, while regrettable, feels correct to me.


best, Eliot
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