[plt-scheme] possible discrepancy between documentation and actual usage of Typed Scheme

From: Sam TH (samth at ccs.neu.edu)
Date: Wed Jul 2 09:05:11 EDT 2008

First, I apologize for the outdated screenshots, which I will fix very soon.

Second, there is no longer (since version 4) a 'Typed Scheme' language
level, selectable in the Language menu of DrScheme.  This is part of a
general shift in the project away from specifying such things in the
IDE, and instead making them part of the program itself.  This has a
number of advantages:

1. Other tools can understand and process the code (such as the
command-line bytecode compiler).
2. You can have projects which use multiple languages
3. The semantics of PLT Scheme inside modules is fundamentally saner
than the interactive top-level.

For all of these reasons, and more, we strongly encourage you to write
all of your PLT Scheme programs, including Typed Scheme ones, in
modules.  One of the reasons for the creation of `#lang' is to make
this easier.  Especially if you plan to use Typed Scheme more in the
future, modules are the only way to go.

sam th

2008/7/2 Benjamin L. Russell <DekuDekuplex at yahoo.com>:
> According to the screen featured on the "Typed Scheme" homepage
> (http://www.ccs.neu.edu/home/samth/typed-scheme/), it should be
> possible to select "Typed Scheme" as a language so that it comes up
> listed as "Language: Typed Scheme" in the interactions panel of
> DrScheme, version 4.0.1, english.
> However, when I actually go to the "Language -> Choose Language..."
> menu item, it is not listed in the language list, and apparently is
> only available in the "Module" language if, as according to the Web
> page "Typed Scheme: Scheme with Static Types"
> (http://docs.plt-scheme.org/typed-scheme/index.html), I type:
>  #lang typed-scheme
> in the definitions panel.
> Further, if I choose language "Module" and then type:
> (require typed-scheme)
> in the interactions panel, DrScheme returns the following error
> message:
>> Module Language: There must be a module in the
>> definitions window. Try starting your program with
>>   #lang scheme
>> and clicking 'Run'.
> I would like to choose "Typed Scheme" as a language without having to
> define a module, similarly to with the other languages listed.
> Further, I plan to use Typed Scheme increasingly in the future, and
> would appreciate a straightforward, easy way of choosing Typed Scheme
> as a default language without having to type:
>  #lang typed-scheme
> in the definitions panel every time.
> Is there any way to do this?
> Are there any plans to list "Typed Scheme" as a language, similar to
> the other languages, in the "Choose Language" dialog box in the near
> future?
> -- Benjamin L. Russell
> _________________________________________________
>  For list-related administrative tasks:
>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme

sam th
samth at ccs.neu.edu

Posted on the users mailing list.