Hi Matthew Yes, I have (define undefined (letrec ((x x)) x)) in some of my programs. No, the backward incompatibility would not hurt me. A few simple changes in my code would be sufficient, I would not need the `racket/undefined` library. I could replace (letrec ((x x)) x)) by (let () (struct undefined ()) (undefined)). Even better for not confusing intentional undefined with unintended undefined. AFAIAC: go ahead! Jos
> -----Original Message----- > From: users [mailto:users-boun...@racket-lang.org] On Behalf in some of my programs. > Of Matthew Flatt > Sent: viernes, 18 de abril de 2014 15:55 > To: users@racket-lang.org > Subject: [racket] #<undefined> and backward compatibility > > This message is about an experiment that would improve Racket > but introduce a backward incompatibility. We'd like more > information about how the change affects your code (see > questions at the end). > > Undefined > --------- > snip > > To make a decision, we need more input: > > * Does the change affect your programs? > > You can try a development snapshot from either of the sites listed > here: > > http://pre.racket-lang.org/ > > * Is this kind of backward incompatibility ok? > > We'll base a decision on how the experiment turns out, but > especially if the experiment goes well, a clear mandate from the > Racket community would seal the deal. > > Thanks! > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
