On Jul 10, 2012, at 11:33 PM, Eli Barzilay wrote: > On Saturday, Matthias Felleisen wrote: >> >> The more general idea is that there is an alternative design space >> out there where you want 'boxes' that signal errors when touched by >> strict functions. You need these every time you want transparent >> transitions from one point in the computational spectrum to another. >> >> ;; --- >> >> And one more level up, I am thinking of selling Racket as a >> wide-spectrum programming language, the first one that introduces >> "safe" or "transparent" transitions properly. > > To combine both of these and my general wish for how the lazy language > would evolve: it would be nice beyond words if there was some new > implicit `#%value' macro wrapped around places that require a value. > With that, an implementation of a lazy language would be trivial, > together with all of the related similar-in-spirit languages. > > (To relate this to another recent thing -- having a no-value thing > that doesn't leak out is too restrictive for some uses (as I need to > write in the followup I promised), but a way to loosen that > restriction so you can pass around no-values and avoid a damaging leak > would be to make such a `#%value' check for them... But that's of > course just vague hand-waving that would naively suffer from the same > perfomance problems...)
Eli's write-up reminded me that we need these things for MultiLisp-tyle futures, too. And yes, #%value would be the right thing in a small model I just don't know how to add this to a language with primitive functions. _________________________ Racket Developers list: http://lists.racket-lang.org/dev
