Beau­tiful Racket

1. 

   Please have Racket v7.3 and DrRacket (or the Racket-editing envi­ron­ment you prefer) ready to go on your laptop. You can use Mac OS, Windows, or Linux. More detailed instruc­tions here.

2. 

   Please be familiar with how to open a terminal window and enter commands like cd and raco and racket.

3. 

   Please install v1.6 of the beautiful-racket package:

   

   raco pkg install beautiful-racket

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   sh$ raco pkg install beau­tiful-racket

   
   

   If you’ve installed in the past, use

   

   raco pkg update beautiful-racket

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   sh$ raco pkg update beau­tiful-racket

   
   

   to ensure you have the newest version.

   

   To check that it worked, try this on the command line (the -l switch tells racket to start with a partic­ular module):

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   racket -l br/test

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   sh$ racket -l br/test

   
   

   You should see this:

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   You installed beautiful-racket correctly.

   

   You installed beau­tiful-racket correctly.

   
4. 

   During the class, we’ll be working through a series of toy languages. Create a work direc­tory for these languages some­where conve­nient (e.g., in your home direc­tory, or on your desktop). Call it what­ever you want. But I’ll refer to it as the work direc­tory.

5. 

   Inside this direc­tory, create an "info.rkt" file as follows:

   /path/to/work/info.rkt

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   #lang info
   (define collection 'multi)

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   #lang info
   (define collec­tion 'multi)

   
   

   This doesn’t do anything perma­nent or nefar­ious—it just makes the subdi­rec­to­ries of work acces­sible as Racket module paths (demo below).

6. 

   From the command line, link this direc­tory as a package:

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   cd /path/to/work
   raco pkg install

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   sh$ cd /path/to/work
   sh$ raco pkg install

   
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   You’ll see a status message like this:

   

   Linking current directory as a package
   raco setup: version: 7.3.0.6
   raco setup: platform: x86_64-macosx [3m] ···

   

   Linking current direc­tory as a package
   raco setup: version: 7.3.0.6
   raco setup: plat­form: x86_64-macosx [3m] ···

   
7. 

   In class, you’ll create subdi­rec­to­ries for the toy languages within this work direc­tory. So the modules for #lang foo will go in /path/to/work/foo. Then they’ll be acces­sible from the #lang line in Racket.

   

   To verify that this works, create a new foo/main.rkt file in your work direc­tory:

   path/to/work/foo/main.rkt

   

   #lang br/quicklang
   (provide (rename-out [mb #%module-begin]))
   
   (define-macro (mb . _)
     #'(#%module-begin (displayln "You did it")))
   
   (module reader syntax/module-reader
     foo)

   

   #lang br/quick­lang
   (provide (rename-out [mb #%module-begin]))
   
   (define-macro (mb . _)
     #'(#%module-begin (displayln "You did it")))
   
   (module reader syntax/module-reader
     foo)

   
   

   Then, in a new DrRacket window, run this source file:

   test.rkt

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   #lang foo

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   #lang foo

   
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   This will produce the result:

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   You did it

   

   You did it

   
8. 

   After class ends—not now!—you can unlink the work direc­tory:

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   raco pkg remove work

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   sh$ raco pkg remove work