<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div> </div><div>We discussed this idea early on -- based on work by Casey and Robby and our own reasoning -- and I am pretty sure it was on your list. If it is not there, we should bring it in quickly. This should improve performance quite a bit. -- Matthias</div><div> </div><div> </div> <div><div>On Sep 10, 2013, at 4:59 AM, Sam Tobin-Hochstadt wrote:</div> <blockquote type="cite">I implemented what I thought would do this a long time ago, so if it isn't there then I must be misremembering or things have changed in the code to make it not happen.Sam <div class="gmail_quote">On Sep 9, 2013 9:13 PM, "Eric Dobson" <<a href="mailto:eric.n.dobson@gmail.com">eric.n.dobson@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> When did you add this? Last time I checked (June-ish) this was not added. Can you point to the code that does it? On Mon, Sep 9, 2013 at 5:55 PM, Sam Tobin-Hochstadt <<a href="mailto:samth@cs.indiana.edu">samth@cs.indiana.edu</a>> wrote: > Not only did our own Sam write about this, but he thought that he changed > Typed Racket to do this. Am I missing something here, or are you describing > more optimization than we do already or ...? > > Sam > > On Sep 9, 2013 8:33 PM, "Robby Findler" <<a href="mailto:robby@eecs.northwestern.edu">robby@eecs.northwestern.edu</a>> wrote: >> >> FWIW, this is something that's been studied in small calculi in the >> literature. Nothing that will have to get thru all of the little details >> that you have to get right to make it work in a real language design like >> TR, but maybe you'll find some useful ways to look at the problem. (Mostly >> the papers I'm thinking of have Jeremy Siek as a co-author but there are >> others, including our own Sam.) >> >> Robby >> >> >> On Mon, Sep 9, 2013 at 7:14 PM, Eric Dobson <<a href="mailto:eric.n.dobson@gmail.com">eric.n.dobson@gmail.com</a>> >> wrote: >>> >>> I have ideas to remove about the contracts from TR code, but currently >>> that is only prototyped. >>> >>> Example: >>> >>> #lang typed/racket >>> (provide f) >>> (: f (Number -> Number)) >>> (define (f x) x) >>> >>> Currently f is exported with the contract (number? . -> . number?), >>> but this can be safely reduced to (number . -> . any). This is because >>> the return value contract is checking things we have already ensured >>> statically. IIRC checking return values of functions is much more >>> expensive than just arguments, so this should reduce the cost of TR >>> boundary cost, but I don't have any numbers. >>> >>> On Mon, Sep 9, 2013 at 10:57 AM, Sam Tobin-Hochstadt >>> <<a href="mailto:samth@cs.indiana.edu">samth@cs.indiana.edu</a>> wrote: >>> > On Mon, Sep 9, 2013 at 11:35 AM, Neil Toronto <<a href="mailto:neil.toronto@gmail.com">neil.toronto@gmail.com</a>> >>> > wrote: >>> >> Nice, and thanks for the explanation. Just to make sure I get it: does >>> >> this >>> >> mean fully expanded TR modules are smaller? >>> > >>> > Yes. >>> > >>> >> Does it reduce the number of generated contracts? >>> > >>> > No. >>> > >>> >> >>> >> >>> >> On 09/08/2013 12:24 PM, Sam Tobin-Hochstadt wrote: >>> >>> >>> >>> Typed Racket has to expand into code that registers the type of each >>> >>> module-top-level identifier in the global environment so that other >>> >>> modules can find the types to typecheck with. For example, this >>> >>> program: >>> >>> >>> >>> #lang typed/racket >>> >>> (provide x) >>> >>> (define: x : Integer 1) >>> >>> >>> >>> expands into (greatly simplified): >>> >>> >>> >>> #lang ... >>> >>> (#%provide x) >>> >>> (begin-for-syntax >>> >>> (declare #'x Integer-rep)) >>> >>> (define-values (x) 1) >>> >>> >>> >>> but what is `Integer-rep`? It needs to be an expression that >>> >>> _constructs_ the internal Typed Racket representation of the >>> >>> `Integer` >>> >>> type. Previously, that looked something like this: >>> >>> >>> >>> (make-Union (sort (list Negative-Fixnum-rep Positive-Fixnum-rep >>> >>> ...))) >>> >>> >>> >>> and so on and so forth for the components, all the way down to base >>> >>> types. You can imagine how this gets quite large, especially for >>> >>> large types. >>> >>> >>> >>> However, this is wasteful, because every Typed Racket program, at >>> >>> type >>> >>> checking time, defines a constant that's the representation of the >>> >>> `Integer` type, right here [1]. So instead of serializing an >>> >>> expression that constructs the same thing as `-Int`, we can just >>> >>> *reference* `-Int` in the expanded code. To make that possible, >>> >>> Typed >>> >>> Racket now builds a hash table [2] mapping types (really, their >>> >>> representations) to identifiers that denote those types. Then the >>> >>> serializer just consults this table [3]. >>> >>> >>> >>> It turns out that base types (but no others) already used basically >>> >>> this mechanism, by storing the identifier *in* the type >>> >>> representation. But that's now obsolete, and thus was removed in my >>> >>> subsequent commit. >>> >>> >>> >>> As a result, the type serialization is much smaller. >>> >>> >>> >>> [1] >>> >>> >>> >>> <a href="https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/types/numeric-tower.rkt#L107" target="_blank">https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/types/numeric-tower.rkt#L107</a> >>> >>> [2] >>> >>> >>> >>> <a href="https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/types/base-abbrev.rkt#L23" target="_blank">https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/types/base-abbrev.rkt#L23</a> >>> >>> [3] >>> >>> >>> >>> <a href="https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/env/init-envs.rkt#L51" target="_blank">https://github.com/plt/racket/blob/master/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/env/init-envs.rkt#L51</a> >>> >>> >>> >>> On Sat, Sep 7, 2013 at 3:20 PM, Neil Toronto <<a href="mailto:neil.toronto@gmail.com">neil.toronto@gmail.com</a>> >>> >>> wrote: >>> >>>> >>> >>>> On 09/06/2013 04:14 PM, <a href="mailto:samth@racket-lang.org">samth@racket-lang.org</a> wrote: >>> >>>>> >>> >>>>> >>> >>>>> 56b372c Sam Tobin-Hochstadt <<a href="mailto:samth@racket-lang.org">samth@racket-lang.org</a>> 2013-09-06 >>> >>>>> 14:22 >>> >>>>> : >>> >>>>> | Remember types that are defined, and use them in serialization. >>> >>>>> | >>> >>>>> | This extends a facility already available for base types, >>> >>>>> | making that facility no longer strictly needed. >>> >>>>> | >>> >>>>> | Shrinks the zo size for the `math` package by almost 1MB. >>> >>>>> : >>> >>>>> M .../typed-racket/env/init-envs.rkt | 1 + >>> >>>>> M .../typed-racket/typecheck/def-export.rkt | 7 +- >>> >>>>> M .../typed-racket/typecheck/tc-toplevel.rkt | 31 >>> >>>>> +++--- >>> >>>>> M .../typed-racket/types/abbrev.rkt | 36 >>> >>>>> +++---- >>> >>>>> M .../typed-racket/types/base-abbrev.rkt | 12 ++- >>> >>>>> M .../typed-racket/types/numeric-tower.rkt | 108 >>> >>>>> +++++++++---------- >>> >>>> >>> >>>> >>> >>>> >>> >>>> Would you mind explaining this a little more? It sounds interesting, >>> >>>> and >>> >>>> the >>> >>>> commit almost has my name in it. :) >>> >>>> >>> >>>> Neil ⊥ >>> >>>> >>> >> >>> > >>> > _________________________ >>> > 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> _________________________ Racket Developers list: <a href="http://lists.racket-lang.org/dev">http://lists.racket-lang.org/dev</a> </blockquote></div> </body></html>