Yes, I think this would allow all the optimizations that Eric talked about. Sam <div class="gmail_quote">On Jun 13, 2014 4:26 AM, "Robby Findler" <<a href="mailto:robby@eecs.northwestern.edu">robby@eecs.northwestern.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Would it be useful to get blame information back from a value, just like you can currently get the contract back? Robby On Tue, Jun 10, 2014 at 11:53 AM, Matthias Felleisen <<a href="mailto:matthias@ccs.neu.edu">matthias@ccs.neu.edu</a>> wrote: > > I was thinking of associating the contract with the type from which it comes and no that's not hash-consing. And if it's slower, too bad. -- Matthias > > > > > > On Jun 10, 2014, at 12:47 PM, Eric Dobson <<a href="mailto:eric.n.dobson@gmail.com">eric.n.dobson@gmail.com</a>> wrote: > >> On Tue, Jun 10, 2014 at 6:15 AM, Matthias Felleisen >> <<a href="mailto:matthias@ccs.neu.edu">matthias@ccs.neu.edu</a>> wrote: >>> >>> On Jun 9, 2014, at 6:02 PM, Eric Dobson <<a href="mailto:eric.n.dobson@gmail.com">eric.n.dobson@gmail.com</a>> wrote: >>> >>>>> >>>>> Eric, are you talking about changing the proxy values that wrap HO/mutable >>>>> contracted values? >>>> Yes. I want the proxy values to include information about who agreed >>>> to the contract in addition to the contract agreed to. >>>> >>>> I actually realize that I might need more than just the contract >>>> agreed to because of how TR changes the generated contract to remove >>>> checks for what it guarantees, so that info is not in the contract. >>>> But I believe that can be added back as a structure property on the >>>> contract. >>> >>> >>> Would some form of hash-consing contracts work here? -- Matthias >>> >> >> I don't think so. But not sure exactly what you are proposing. >> >> The issue is that there are 4 contracts here and 2 of them currently >> do not exist at runtime. The 4 are TRs checks/promises on an >> export/import. (Using import for a value flowing into an exported >> function). The promise contracts do not currently exist as removing >> them was my previous optimization (They never fail). What I want to do >> is change the check on import from (array/c symbol?) to (if/c >> (protected>? (array/c symbol?)) any/c (array/c symbol?)). Where >> (protected>? x/c) checks if TR already promised something stronger >> than x/c. >> >> I believe that you are proposing that we can use the identity of the >> contract returned by value-contract to determine what the promised >> contract would have been. This does not work as (Array Symbol) and >> (Array Float) both get translated to (array/c any/c) for export, and >> we would want to lookup different promised contracts for them. We >> could use weak hash map as an extra field but that seems like it would >> be slow. > > > _________________________ > Racket Developers list: > <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a> _________________________ Racket Developers list: <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a> </blockquote></div>