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] On Behalf Of Thierry Goubier 2014-11-10 8:47 GMT+01:00 Henrik Johansen <henrik.s.johan...@veloxit.no <mailto: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