The standard does *not* support - a removeAll: a - [was: Re: [BUG] Collection>>removeAll:]
Richard A. O'Keefe
ok at cs.otago.ac.nz
Wed Sep 11 03:13:28 UTC 2002
Lex Spoon <lex at cc.gatech.edu> wrote:
I still think it's likely -- it's the way I
code, and it's the way I've heard many people suggest coding.
When you do a rewrite by inline expansion of a method,
do you always throw away the assertions, error checks, and guard code?
Because that's what's needed for this example.
It's unreasonable to do full proofs of
correctness, and it's unhelpful to point the finger and say it's so and
so's responsibility to do such an unreasonable thing.
Nobody has suggested proofs of correctness,
only (1) reasonable testing and (2) not throwing away guard code.
| x |
x := self allFooishMembers.
"at this point, is x the same as it was
up above? you'd like it to be!!"
This is discussed in the Smalltalk Style Guide, which is currently at home
or I'd cite the page number. I argued at length (only to be jumped on hard
by A----- G-------) that objects shouldn't hand out references to their
innards, and if they do, they don't have a usable class invariant any more.
In different language, the Smalltalk Style Guide suggests handing out
_new_ collections as a good thing to do.
While I know that C++ 'strstream' is frowned on, it does count as an example.
Once you ask for (and are given) a reference to a ostrstream's buffer,
that's practically _all_ you can do with the ostrstream thereafter.
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