Roman, This approach is unlikely to work out due to separate compilation. Module A can't really affect how module B gets compiled. Your contract-mode appears to be trying to do such a thing.
So it is not clear where the decision on compile mode is made. If it is inside a module, then why not turn them off to remove contracts that enforce things like security? Something like this seems to be "outside" of the language. I have thought that the right place would be inside the compiler or something like the demodularizer. Further, I imagine a general mechanism that turns (if p e (error ...)) into just e Instead of baked-in cooperation with and knowledge of contracts. Jay Sent from my iPhone > On Jun 3, 2014, at 1:16 PM, Roman Klochkov <kalimeh...@mail.ru> wrote: > > Will you accept patch for this, if I'll write it? > > (contract-out ...) will have (id debug-contract-expr > production-contract-expr) instead of (id contract-expr) in syntax > There will be global phase-1 variable > contract-mode : (or/c 'nothing 'production 'pre 'pre-and-past 'all) = 'all > > nothing -- no checks > production -- use production contract if present, otherwise check only > pre-condiction > pre -- check only pre-condiction > pre-and-post -- check pre and post conditions > all -- current behavior > > > > > Tue, 3 Jun 2014 12:47:18 -0400 от Matthias Felleisen <matth...@ccs.neu.edu>: > > Your mail calls for a philosophical answer. If this were Eiffel, you would be > correct. > > But Racket is not Eiffel: > -- we are not a tools company that sells a language > -- we spent our own time on a maintenance effort that goes above and beyond > our jobs > -- and we don't provide a standard language (meant to make developers happy > and its creators famous and wealthy). > > Racket is a programming language programming language [not a typo]. We wish > to go beyond conventional features. When it comes to contracts, this means we > wish to provide (1) higher-order contracts so that we cover the full spectrum > of linguistic features and (2) a programmable toolbox so that programmers can > create their own favorite idioms -- above and beyond the stuff available in > standard languages. > > We fully understand that expanding the horizons of the language puts some > burden on programmers. Every programmer may have to develop his own > techniques and tools and idioms for our new features. We balance this burden > with a catalog-driven on-line library, where programmers can register little > more than a github URL to share such libraries. > > With apologies for the extra burden and the non-technical answer -- Matthias > > > > > > > > On Jun 3, 2014, at 12:24 PM, Roman Klochkov <kalimeh...@mail.ru> wrote: > > > There should be _standard_ check-modes. With global variable (or better > > compile-mode). > > > > Because, I can in my own libraries make this 4 or even more modes. But I > > use 3d-party or standard library. And I cannot rewrite them all to my 4 > > modes. > > Even if another developer will use the same idea, he or she will have own > > modes and own variable to set them. > > > > > > Tue, 3 Jun 2014 07:47:37 -0400 от Matthias Felleisen <matth...@ccs.neu.edu>: > > > > You can program these scenarios with option contracts; see comparison in > > paper. Perhaps it's time to write this up as a chapter for the Guide. > > > > > > On Jun 3, 2014, at 12:38 AM, Daniel Prager wrote: > > > >> > I propose something like two contracts: for debug and production modes. > >> > >> Eiffel compilers implement a sliding scale of contract-checking, something > >> like: > >> • Check nothing [naive] > >> • Check pre-conditions only [good for production - quick] > >> • Check pre- and post-conditions only [can be slow] > >> • Check pre- and post-conditions and invariants [van be very slow] > >> [Loop and ad hoc assertions would have been in there too.] > >> > >> Post-conditions and invariants can be *very* expensive to check, but are > >> great when debugging. > >> > >> Pre-condition checking is typically cheap, and quickly tells you when > >> trusted code is being called with bad arguments. > >> > >> Recommeneded development practice was to start with all contracts checked, > >> and as one's code iterated towards trustworthiness turn down the > >> checking-level (but leave pre-conduitions on) and enjoy the huge speed > >> boost. > >> > >> There's value in being able to control checking on a per module basis, > >> essentially doing deep checks on newer / less-tested / less-trusted parts > >> of the system. > >> > >> How does the picture change with higher-order contracts and checking at > >> module boundaries? > >> > >> Dan > >> > >> > >> > >> On Tue, Jun 3, 2014 at 6:20 AM, Roman Klochkov <kalimeh...@mail.ru> wrote: > >> The problem is that, when debbugging, contract should be precise. For > >> example, insert-in-sorted-queue may check that queue is orted before and > >> after the function. > >> But inserting the element is O(log n) and testing will be O(n). > >> > >> option contracts -- 1) unstable 2) should be turned off and on > >> individually. > >> > >> For quick hack, I'll simply redefine contract-out and recompile all. But I > >> propose something like two contracts: for debug and production modes. > >> > >> > >> Mon, 2 Jun 2014 15:49:05 -0400 от Matthias Felleisen > >> <matth...@ccs.neu.edu>: > >> > >> > >> On Jun 2, 2014, at 3:42 PM, Roman Klochkov <kalimeh...@mail.ru> wrote: > >> > >> > Is there a way to disable all contract checks? > >> > > >> > Suppose, I debugged my program and sure that it is reliable. I disable > >> > debugging, but as I understand, contracts are still checked in every > >> > function. > >> > But I want to maximize the performance of my program. Is there a way to > >> > do that or I have to manually hack racket/contract/base to do that? > >> > >> > >> No. > >> > >> ;; --- > >> > >> Programmers who disable assertion checking as they are deploying software > >> are like people who wear life vests on land when they learn about the > >> theory of sailing and take them off as soon as they board the boat for > >> practical exercises on the water. -- somebody famous > >> > >> ;; --- > >> > >> You will need to define a version of provide and/or contract-out that > >> throws away contracts based on a switch. > >> > >> Or you check out option contracts and use those. > >> > >> -- Matthias > >> > >> > >> > >> -- > >> Roman Klochkov > >> > >> ____________________ > >> Racket Users list: > >> http://lists.racket-lang.org/users > >> > >> > >> > >> > >> -- > >> Daniel Prager > >> Agile/Lean Coaching, Software Development and Leadership > >> Startup: www.youpatch.com > >> Twitter: @agilejitsu > >> Blog: agile-jitsu.blogspot.com > > > > > > > > -- > > Roman Klochkov > > > > -- > Roman Klochkov > ____________________ > Racket Users list: > http://lists.racket-lang.org/users
____________________ Racket Users list: http://lists.racket-lang.org/users
