On Tue, Jul 15, 2003 at 11:50:40PM +0000, John Chambers wrote: > Phil Taylor writes: > | Bryan Creer wrote: > | >Unfortunately, to really to solve compatability problems you need a > | >masochistic altruist who will go back and remove all the line-break !s > | >from all the > | >tune files created with abc2win over the last eight years or so which > | >might annoy > | >the people who chose to put them in. (I'm not volunteering.) > | > | Yeah, that's the rub. The thing to bear in mind is that we don't have to > | stay compatible with abc2win, since the people who use that program don't > | need the more advanced features which we are adding to the language. > | On the other hand, we do have to maintain some compatibility with abc2win's > | files, because they are priceless. What we must avoid is adding something > | to the language which prevents new programs which conform to the newest > | standard from being capable of dealing with abc2win's files. > > That's a good summary. And it's not all that difficult to spot the > abc2win ! usage. The !...! syntax for musical annotations is rather > limited in what text is allowed. In particular, things like bar > lines, brackets, parens, colons, etc don't seem to occur inside the > !...! things. So when you find a !, you can just scan for the next !, > and if you find any of these funny chars (or hit the end of the > line), you know it was an abc2win ! char. Granted, this is kludgey > and ad hoc, but it's not all that bad to implement.
I'm not sure I've got my head round all the issues of the !decoration! syntax, but is it not the case that the program has, somewhere, to know how to draw each of those things ? So they must be enumerated somewhere, somehow, in the code ? So it should be possible to look at anything contained in a pair of !'s and see if it matches any of those ? As you said somewhere else, ugly amounts of lookahead (particularly in C), but doable. And anything else must be a staffbreak ? Perhaps we're going to end up inventing the idea of precedence rules to solve ambiguities ? -- Richard Robinson "The whole plan hinged upon the natural curiosity of potatoes" - S. Lem To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
