Jay, I agree. This would be a good starting point, so others can find it too.
On Jan 19, 2012, at 2:02 PM, John Clements wrote: > I think the below would make a good PLT blog post, perhaps with an opening > paragraph about how much cheaper the stateless web-server can be. > > John > > > On Jan 3, 2012, at 10:33 PM, Galler wrote: > >> >> >> On the subject of porting #lang racket to #lang web-server code >> >> I provide a few lessons learned for the archives for the next person to >> attempt this. >> >> >> 1) Bindings, Serializability , and anonymous functions >> >> 1A) the predicate serializable? from racket/serializable is invaluable >> >> #lang web-server code will not transform if there are non-serializable >> constructs in the dynamic extent of the invocation of send/suspend >> >> some minor surprises/lessons learned: >> >> 1B) anonymous functions are not serializable >> >> (serializable? (λ (x) x)) ;->#f >> >> 1C) anonymous functions in a list are not serializable >> >> (serializable? (car (list (λ (x) x) (λ (x) x)))) ;->#f >> >> 1D) once given a module-level binding, anonymous functions become >> serializable >> >> (define foo (list (λ (x) x) (λ (x) x))) >> >> (serializable? (car foo)) ;->#t >> >> 1E) void is not serializable >> >> (serializable? void) ;->#f >> >> 1F) anonymous functions bound within a letrec form are serializable >> >> >> 2) 'attempt to cross a continuation barrier' exceptions >> >> invocations of native continuations reified with call/cc seemed to >> frequently throw this error >> >> I haven't done enough analysis to understand why and under what conditions, >> but in all cases I was able to remediate by enclosing the invocation as >> follows. >> >> (call-with-continuation-prompt k (default-continuation-prompt-tag) >> >> 3) with-continuation-marks, continuation-marks, and >> current-continuation-marks can be used to replace dynamic-wind >> >> >> Again, thank you. I think the stateless web-language is important technology >> and must have required an enormous amount of work to implement. >> >> Anedcotally, application speed seems at or better than the stateful code. >> >> R./ >> Zack >> >> On Sun, Jan 1, 2012 at 4:36 PM, Jay McCarthy wrote: >> >> > On Sat, 31 Dec 2011 20:03:02 -0600,Robby Findler >> > <ro...@eecs.northwestern.edu> mumbled: >> > > I'm not sure if the web-server supports continuation marks or not >> > >> > The stateless transformation does support continuation marks, provided >> > the keys and values are serializable. (Parameters/exception handlers are >> > not >> > supported because the key is not serializable.) >> > >> > Jay >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
