hmmm ... I am getting some error. My repl session below. I am using 'db' module.
> bind-prepared-statement . Type Checker: untyped top-level identifier lifted.474 in: bind-prepared-statement > Not sure what to make of it. My impression was the typed/untyped code mix well. Am i missing something ?? Bikal On Mon, Apr 30, 2012 at 10:54 PM, Vincent St-Amour <[email protected]>wrote: > The REPL prints types automatically: > > Welcome to Racket v5.3.0.4. > -> vector-ref > - : (All (a) ((Vectorof a) Integer -> a)) > #<procedure:vector-ref> > -> (define: x : String "Hello") > -> x > - : String > "Hello" > -> > > > Is this what you had in mind? > > Vincent > > > > At Mon, 30 Apr 2012 22:23:01 +0100, > Bikal Gurung wrote: > > > > [1 <multipart/alternative (7bit)>] > > [1.1 <text/plain; ISO-8859-1 (7bit)>] > > Sam, > > > > Is there a function in racket which will - given a name - display the > > function/variable signature in the REPL? > > > > I am thinking about haskell prelude(REPL) that gives me the type > signature > > when I enter :t <func name> in the repl? > > > > With Thanks > > Bikal > > > > On Mon, Apr 30, 2012 at 1:48 PM, Sam Tobin-Hochstadt <[email protected] > >wrote: > > > > > On Mon, Apr 30, 2012 at 12:51 AM, Bikal Gurung <[email protected]> > wrote: > > > > Hi All, > > > > > > > > I am investigating typed racket. I was wondering if someone could > help > > > with > > > > answering the questions below. > > > > > > > > 1) Can we mix/import modules written in untyped racket to a module > that > > > is > > > > used typed racket. I have experimented with a few modules using and > they > > > > seem to work in general but not really sure about the mechanism that > > > makes > > > > it work. How does racket make the untyped code and typed code work > > > together > > > > if they do? Is this in a case by case basis, ie. module/library by > > > library > > > > basis? > > > > > > Yes, you can mix typed modules and untyped modules in the same > > > program. This is one of the most fundamental features of Typed > > > Racket. To use a typed module from an untyped module, just require it > > > -- contracts are inserted automatically to check the operation. To > > > use an untyped module from a typed module, use `require/typed' to > > > specify the type. > > > > > > > 2) What is the canonical racket paradigm? use typed racket or untyped > > > > racket? Or is this more an issue of a preference/style? > > > > > > This is very much an issue of style. I think there are a number of > > > advantages of type systems for maintenance, optimization, > > > documentation, and organization, so I encourage you to use Typed > > > Racket. However, if you use plain Racket, Typed Racket is designed to > > > make it easy to switch, a module at a time, when you decide you want > > > types. > > > > > > > 3) Are typed racket programs faster than untyped ones? The > documentation > > > > says so but I was wondering if there has been any benchmark or study > > > being > > > > done on this topic. > > > > > > Yes, Typed Racket has an optimizing compiler (by Vincent St-Amour) > > > which uses the type information to make your program go faster. You > > > can see some benchmark results in our papers > > > http://www.ccs.neu.edu/racket/pubs/padl12-stff.pdf and > > > http://www.ccs.neu.edu/racket/pubs/pldi11-thacff.pdf . > > > > > > > 4) Can typed racket module be used in the context of untyped racket > > > module? > > > > > > Yes, you can just `require` the typed module, and it should work. > > > > > > > 5) Is there a Hindlye/Milner style type inferencing algorithm for > typed > > > > racket being worked on? > > > > > > The Typed Racket type system contains a number of features that go > > > beyond what's supported in Hindley/Milner style type systems, and so > > > we can't use that inference system. Currently, Typed Racket uses > > > local type inference to infer many of the types in your program, but > > > we'd like to infer more of them -- this is an ongoing area of > > > research. However, inferring all the types in the program, the way > > > that ML and Haskell do, is not a goal of Typed Racket -- having type > > > annotations there makes the program self-documenting and easier to > > > understand, improves type error messages, and supports advanced type > > > system features. > > > > > > Thanks for your interest in Typed Racket, and if you have any more > > > questions, please ask. > > > -- > > > sam th > > > [email protected] > > > > > [1.2 <text/html; ISO-8859-1 (quoted-printable)>] > > > > [2 <text/plain; us-ascii (7bit)>] > > ____________________ > > Racket Users list: > > http://lists.racket-lang.org/users >
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