[racket] Where to put the ellipsis?

Ahhh!! Your suggestion really simplifies and cleans up my original model!

Thanks :-)



On Mon, Jul 15, 2013 at 12:26 PM, Matthias Felleisen
<matthias at ccs.neu.edu>wrote:

>
> I don't think you need 'dots' for what you want.
>
> Here is how you can organize your states:
>  n -- name of current thread
>  C -- control of current thread
>  E -- env of current thread
>  S -- global store
>  K -- continuation of current thread
>  T -- thread pool : Name |-->f <C E K> (a finite map from names to states)
>
> Then your beta-value reduction works as normal on the registers C through
> K and you can keep n and T opaque.
>
> Thread switches swap in/out the relevant C E Ks.
>
> No ellipses needed to single out the current thread.
>
>
>
> On Jul 15, 2013, at 12:40 PM, Monica Tomson <monica.tomson at gmail.com>
> wrote:
>
> >
> >
> >
> > On Mon, Jul 15, 2013 at 6:48 AM, Matthias Felleisen <
> matthias at ccs.neu.edu> wrote:
> >
> > Is this supposed to be a CESK machine state where you apply \x.M to V
> (actually V and the empty env, which is a highly unusual left-hand side)?
> >
> > Yeah. the machine is a CESK machine, and the reduction rule is function
> application essentially.
> >
> > The change is that I want to model thread spawn and join,
> > which I think I can remodel the whole machine  in the way  that I can
> still "plug" the previous rules, except join and spawn, which i need to
> write new). and So, the model with thread is:
> >
> >  (context (M ε κ))
> >  (thread (tid context) )
> >  (threads  (thread ...))
> >
> > at the same time using a global store (Store) for simplicity, but really
> a state is a threads * store
> >
> > and for the reduction with syntax error reported in the previous rule,
> >  (Some mistakes in  the original post, so I copy-past it again below),
> > I try to use pattern matching the treads list, which tries to get the
> first thread entry from the list of threads,
> >
> > (-->
> >     (((tid   (V ε (fn ((λ X M) ε_f) κ))) ...) S) ; tid, context
> >      (((tid  (M  (update ε_f X σ_n) κ)) ...) S)
> >      tcesk3
> >      (where σ_n ,(fresh-σ))
> >      (side-condition
> >       (not (redex-match thread-cesk-iswim-plus X (term V ))) )  ;syntax:
> missing ellipsis with pattern variable in template in: V
> >     (side-condition
> >       (begin (store-update! (term σ_n) (term (V ε)) Store) #t)))
> >
> > I am not sure the design or the whole things making sense or not, but
> just trying to do some exercise of using PLT-Redex...
> >
> > Thanks,
> > --Monica
> >
> >
> >
> > On Jul 15, 2013, at 4:28 AM, Monica Tomson wrote:
> >
> > > Hi,
> > >
> > > I have the following reduction rule, it keeps on throwing the
> compiling error:missing ellipsis with pattern variable in template in: V
> > >
> > > I am confused where to put the ellipsis?
> > >
> > >
> > > (--> ;((V ε) S (fn ((λ X M) ε_f) κ))
> > >         ;((M (update ε_f X σ_n)) S κ)
> > >      ((tid  (V ε (fn ((λ X M) ε_f) κ))) ...) ; tid, context
> > >      ((tid  (M  (update ε_f X σ_n) κ)) ...)
> > >      tcesk3
> > >      (where σ_n ,(fresh-σ))
> > >      (side-condition
> > >       (not (redex-match thread-cesk-iswim-plus X (term V ))) )  ;
> ERROR: syntax: missing ellipsis with pattern variable in template in: V
> > >     (side-condition
> > >       (begin (store-update! (term σ_n) (term (V ε)) Store) #t)))
> > >
> > > Thanks,
> > >
> > > --Shuying
> > > ____________________
> > >  Racket Users list:
> > >  http://lists.racket-lang.org/users
> >
> >
>
>


-- 
Monica
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