---------- Forwarded message ---------- From: L Peter Deutsch <l...@major2nd.com> Date: 2009/12/16 Subject: Re: [BUG] [ :a | ] value: 1 To: eliot.mira...@gmail.com Cc: reng...@gmail.com, dan.inga...@sun.com, squeak-...@lists.squeakfoundation.org
Good Heavens. To think that that something like this would surface after all these years.... I agree with Lukas. The block should return nil. The ANSI standard is broken -- the fewer special cases a standard has, the better. I didn't write the Smalltalk source-to-bytecode compiler, and if I had, I would have made it return nil if I had had my wits about me. OTOH, Dan may know of a historical reason why things were done this way -- perhaps there's some fairly common usage pattern that I've forgotten that makes the return-the-last-argument definition worthwhile. I agree that changing this is likely to break code. All the same, I am somewhat in favor of changing it in the ANSI standard. If that is done, I would hope someone would create a tool to do a pass over Smalltalk source code and browse any occurrences of the problematic construct. (Fixing them automatically might not be a good idea, since the value that the block returns might not actually be used, and if not, no fix would be needed.) Fortunately, this is an example where it's easy, if a little unsightly, to write code so that it will work under either interpretation (by explicitly include the desired return value in the block). L Peter Deutsch P.S. Writing standards is really very tricky. If one writes a standard too early, it's likely to get something important wrong simply from not enough experience; but if you write it too late, it may be impossible to get implementations to follow it, or the standard may have to compromise on quality to conform to the implementations. A depressing example of this is HTML5, where I'm told the standards committee pretty much caved to whatever the major browsers had actually done, regardless of how poorly designed it was. ---------------------------------------------------------------- -- Lukas Renggli http://www.lukas-renggli.ch _______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
