Sam,<div><br></div><div>Is there a function in racket which will - given a name - display the function/variable signature in the REPL?</div><div><br></div><div>I am thinking about haskell prelude(REPL) that gives me the type signature when I enter :t <func name> in the repl?</div> <div><br></div><div>With Thanks</div><div>Bikal<br><br><div class="gmail_quote">On Mon, Apr 30, 2012 at 1:48 PM, Sam Tobin-Hochstadt <span dir="ltr"><<a href="mailto:samth@ccs.neu.edu" target="_blank">samth@ccs.neu.edu</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On Mon, Apr 30, 2012 at 12:51 AM, Bikal Gurung <<a href="mailto:gbikal@gmail.com">gbikal@gmail.com</a>> wrote:<br> > Hi All,<br> ><br> > I am investigating typed racket. I was wondering if someone could help with<br> > answering the questions below.<br> ><br> > 1) Can we mix/import modules written in untyped racket to a module that is<br> > used typed racket. I have experimented with a few modules using and they<br> > seem to work in general but not really sure about the mechanism that makes<br> > it work. How does racket make the untyped code and typed code work together<br> > if they do? Is this in a case by case basis, ie. module/library by library<br> > basis?<br> <br> </div>Yes, you can mix typed modules and untyped modules in the same<br> program. This is one of the most fundamental features of Typed<br> Racket. To use a typed module from an untyped module, just require it<br> -- contracts are inserted automatically to check the operation. To<br> use an untyped module from a typed module, use `require/typed' to<br> specify the type.<br> <div class="im"><br> > 2) What is the canonical racket paradigm? use typed racket or untyped<br> > racket? Or is this more an issue of a preference/style?<br> <br> </div>This is very much an issue of style. I think there are a number of<br> advantages of type systems for maintenance, optimization,<br> documentation, and organization, so I encourage you to use Typed<br> Racket. However, if you use plain Racket, Typed Racket is designed to<br> make it easy to switch, a module at a time, when you decide you want<br> types.<br> <div class="im"><br> > 3) Are typed racket programs faster than untyped ones? The documentation<br> > says so but I was wondering if there has been any benchmark or study being<br> > done on this topic.<br> <br> </div>Yes, Typed Racket has an optimizing compiler (by Vincent St-Amour)<br> which uses the type information to make your program go faster. You<br> can see some benchmark results in our papers<br> <a href="http://www.ccs.neu.edu/racket/pubs/padl12-stff.pdf" target="_blank">http://www.ccs.neu.edu/racket/pubs/padl12-stff.pdf</a> and<br> <a href="http://www.ccs.neu.edu/racket/pubs/pldi11-thacff.pdf" target="_blank">http://www.ccs.neu.edu/racket/pubs/pldi11-thacff.pdf</a> .<br> <div class="im"><br> > 4) Can typed racket module be used in the context of untyped racket module?<br> <br> </div>Yes, you can just `require` the typed module, and it should work.<br> <div class="im"><br> > 5) Is there a Hindlye/Milner style type inferencing algorithm for typed<br> > racket being worked on?<br> <br> </div>The Typed Racket type system contains a number of features that go<br> beyond what's supported in Hindley/Milner style type systems, and so<br> we can't use that inference system. Currently, Typed Racket uses<br> local type inference to infer many of the types in your program, but<br> we'd like to infer more of them -- this is an ongoing area of<br> research. However, inferring all the types in the program, the way<br> that ML and Haskell do, is not a goal of Typed Racket -- having type<br> annotations there makes the program self-documenting and easier to<br> understand, improves type error messages, and supports advanced type<br> system features.<br> <br> Thanks for your interest in Typed Racket, and if you have any more<br> questions, please ask.<br> <span class="HOEnZb"><font color="#888888">--<br> sam th<br> <a href="mailto:samth@ccs.neu.edu">samth@ccs.neu.edu</a><br> </font></span></blockquote></div><br></div>