I believe that x - - y would give you an error. 4 - - 5 in parsing is a different beast, because you consider - 5 as a single token.
Thierry 2014-11-10 12:36 GMT+01:00 Henrik Johansen <henrik.s.johan...@veloxit.no>: > In VisualWorks: > 3 @ *Argument expected ->*- 5 > > I guess what one expects is a matter of habit, personally I'd expect x - - > y to yield a parsing error. > > Cheers, > Henry > > On 10 Nov 2014, at 12:06 , PBKResearch <pe...@pbkresearch.co.uk> wrote: > > I have tried this on my latest Dolphin (Pro 6.1 Beta 2): > 3 @ -5 is accepted and interpreted correctly. > 3 @ - 5 is rejected with message: 'Error - incorrect expression start'; > the caret is pointing at the - sign. > So the Opal behaviour does not mirror that of Dolphin. > > Hope this helps > > Peter Kenny > > > *From:* Pharo-users [mailto:pharo-users-boun...@lists.pharo.org > <pharo-users-boun...@lists.pharo.org>] *On Behalf Of *Thierry Goubier > > 2014-11-10 8:47 GMT+01:00 Henrik Johansen <henrik.s.johan...@veloxit.no>: > > 3 @ -5 is not a problem, and accepted by both. > 3 @ - <space> 5 is what I object to (and Opal allows) > > > > RBParser allows this one even if old Compiler dissallows it (i.e. in Pharo > 2). > > I haven't tracked if Opal follows the RBParser on that or if this is the > reverse (Opal pushed changes on RBParser). I suspect all things RB in Pharo > (and Squeak?) are a port from the Dolphin version of RB, which means this > is allowed in quite a few other smalltalks (Dolphin?, VW?). > > I haven't checked if the SmaCC Smalltalk parser accept that. > Note: 4 - 5 in RBParser does what you would expect. 4 - - 5 as well. > > > 3 @-5 and/or 3 @- 5 is (rightly) disallowed by both. > > > > That one is easier and expected. > My position would be twofold: > - RBParser is, IMHO, a good parser and I would follow its interpretation. > That Opal reuses it is a good point for me. > - As a programming language designer (and parser implementor), accepting - > 5 is user friendly, but a bit too contextual in the lexer to be nice to > implement. > > Thierry > > > > Cheers, > Henry > > >
