Need feedback on simple idea
Stephane Ducasse
ducasse at iam.unibe.ch
Thu Apr 10 20:36:42 UTC 2003
Hi
I would like to know what you would think of the following change in
Smalltalk.
We are really in the mood to make some change in the compiler to play
with the idea
for our research.
remove direct access to instance variables a la self
a class still defines instance variable but we cannot access directly
instance variables accessors are automatically optimized to use direct
access by the compiler.
Pros:
simplicity/uniformity no distinction between state and methods.
Cons:
no private iv anymore anymore (except if we try to have a clever schema
that lets the programmer writing self x while the byte code remove the
send)
with this schema we could have private instance variables but be
forced to used a normal method to make public an accessor.
m
self x
<=>
m
x
public accessor could be then
getX
self x
Applicability to Squeak:
- would break all the accessors that do something more that accessing
(self changed) but we could use a dedicated parser/compiler so that the
changes only impact a subset.
Prof. Dr. Stéphane DUCASSE
http://www.iam.unibe.ch/~ducasse/
"if you knew today was your last day on earth, what would you do
different? ... especially if,
by doing something different, today might not be your last day on
earth" Calvin&Hobbes
"The best way to predict the future is to invent it..." Alan Kay.
Open Source Smalltalks: http://www.squeak.org,
http://www.gnu.org/software/smalltalk/smalltalk.html
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