I came up with a fairly boring example that does use places. Note that you
have to put this in a module and save the file:
> #lang racket
> (require racket/serialize
> web-server/lang/serial-lambda
> )
> (define current-place
> (make-parameter 'initial))
> (define (main)
> (define p
> (place ch
> (parameterize ([current-place 'p])
> (define proc
> (deserialize (place-channel-get ch)))
> (place-channel-put ch (proc)))))
> (place-channel-put/get p (serialize
> (serial-lambda ()
> (format "I was run on place ~a."
> (current-place))))))
Then at the REPL, you can do:
> > (main)
> "I was run on place p."
-Philip
On Tue, Jan 17, 2017 at 9:07 PM, Philip McGrath <phi...@philipmcgrath.com>
wrote:
> For a quick example (without places), if you enter this in the definitions
> window of Dr. Racket:
>
>> #lang racket
>> (require web-server/lang/serial-lambda
>> racket/serialize
>> )
>> (define serialized-proc
>> (serialize (serial-lambda (x)
>> (printf "Your number is: ~a" x))))
>> serialized-proc
>> ((deserialize serialized-proc) 42)
>
> This is what you will get when you run the program:
>
>> '((3) 1 (('anonymous-module . "lifted.3")) 0 () () (0))
>> Your number is: 42
>
>
> There are a few caveats with serial-lambda. A big one is that you can't
> use it in the REPL: it has to be in a module context, so that there's a way
> to use the serialization information later. A second caveat is that any
> lexical values in the closure of serial-lambda must themselves be
> serializable: this is an instance of the general rule that, for serialize
> to succeed, all the nested contents of the data structure to be serialized
> must be serializable, not just the outermost container. Here's an example:
>
> #lang racket
>> (require web-server/lang/serial-lambda
>> racket/serialize)
>> (define (make-proc lexical-value)
>> (serial-lambda (immediate-arg)
>> (printf (string-append "This value is part of the closure, so \n"
>> "it must be serializable:\n\t ~a\n")
>> lexical-value)
>> (printf "The immediate argument can be anything:\n\t ~a\n"
>> immediate-arg)))
>> (struct opaque ())
>> (define works
>> (make-proc (list 'apples 'peaches 'pears)))
>> ;; calling works on an non-serializable argument succeeds
>> (works (opaque))
>> ;; you can see that the lexical arg shows up
>> ;; in the serialized representation
>> (serialize works)
>> (newline)
>> (define broken
>> (make-proc (opaque)))
>> ;; make-proc will succeed, and broken
>> ;; will appear to work as expected
>> (broken 42)
>> ;; however, attempting to serialize broken
>> ;; will raise an exn:fail
>> (serialize broken)
>
>
> If you have specific questions, I am happy to try to help!
>
> -Philip
>
> On Mon, Jan 16, 2017 at 11:13 PM, Andreas Olsson <photoguy....@gmail.com>
> wrote:
>
>> Strangely I can't get the example working from the docs and serial lambda
>> isn't a cakewalk ether. So if you got a working example please share it!
>>
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