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How To Run SICP Programs in DrScheme

Problem

Getting a program from SICP to run in DrScheme.

Solution

Choose the Proper Language

• In the "Language" menu choose "Choose Language".
• Click the arrow at PLT and then choose "Pretty Big".

Streams

SICP? uses a primitive named cons-stream. Paste the following at the top of the definition window to make this primitive available.

(require (lib "defmacro.ss"))

; cons-stream : obj stream ->  stream
;   construct a stream whose first element is obj and whose tail is stream
;   [cons-stream is a special form]
(define-macro cons-stream
  (lambda (car cdr)
    `(cons ,car (delay ,cdr))))

For other SICP stream functions, see: http://list.cs.brown.edu/pipermail/plt-scheme/2003-March/001945.html.

Non-deterministic programming

Chapter 4.3 on non-deterministic programming uses the special form amb. Insert the following at the top of the definition window.

(require (lib "defmacro.ss"))

(define amb-fail '*)

(define initialize-amb-fail
  (lambda ()
    (set! amb-fail
      (lambda ()
        (error "amb tree exhausted")))))

(initialize-amb-fail)

(define-macro amb
  (lambda alts...
    `(let ((+prev-amb-fail amb-fail))
       (call/cc
        (lambda (+sk)

          ,@(map (lambda (alt)
                   `(call/cc
                     (lambda (+fk)
                       (set! amb-fail
                         (lambda ()
                           (set! amb-fail +prev-amb-fail)
                           (+fk 'fail)))
                       (+sk ,alt))))
                 alts...)

          (+prev-amb-fail))))))

The Picture Language

The picture language is available as a .plt?-file from Michael Sperber.

For instruction on installing it, see ee HowToInstallPLTFile.

To use it, read on.

07:58:14 <soegaard> You were asking about the picture language in SICP, right?
07:58:38 <jim> soegaard: yes
07:58:58 <soegaard> Mike Sperber implemented it for PLT Scheme.
07:59:18 <jim> cool :)

07:59:45 <soegaard> In DrScheme go to the file menu, and choose "Install .plt file"
08:00:07 <soegaard> Then enter
08:00:08 <soegaard> http://www-pu.informatik.uni-tuebingen.de/users/sperber/software/picture.plt

08:06:33 <soegaard> jim: I am looking for documentation to start it, it must be there somewhere

08:13:45 <soegaard> ah!
08:14:22 <soegaard> jim: In the "Language" menu choose "Add TeachPack".
08:15:24 <soegaard> jim: Then choose the file picture.ss hidden in the TeachPack directory (on my machine: C:/documents
and settings/js/Application Date/PLT 208.1/teachpack/picture.ss
08:15:38 <soegaard> jim: Press "Go"
08:15:56 <soegaard> jim: Then try: (paint (corner-split einstein 1))
08:16:30 <jim> soegaard: trying to find the teachpack (I installed the file as root in linux)

08:31:19 <soegaard> jim: And (paint (corner-split einstein 1)) works?
08:32:51 <jim> we're getting there. it knows paint but not corner-split
08:33:19 <jim> hah! it works
08:33:28 <soegaard> jim: ah! I loaded one of the example files first
08:33:32 <jim> (paint einstein)
08:34:08 <soegaard> jim: I loaded example.scm first and corner-split is defined there.
08:34:50 <jim> are there stick figures?

08:36:01 <soegaard> jim: Open the file collects/painters.ss and see all the provided procedures.
08:36:14 <jim> ahh
08:36:21 <soegaard> jim: There is a segments->painter which can be used to make stick figures.
08:37:45 <jim> soegaard: ok, good enough... now how can I make the imagelarger?
08:38:00 <soegaard> use paint-hi-res
08:39:41 <jim> soegaard: -very- good :) thank you very much :)
08:39:51 <soegaard> no problem

Discussion

The amb -macro was taken from "Teach Yourself Scheme in a Fixnum of Days" by Dorai Sitaram. This book is integrated in DrScheme - to read it open the HelpDesk, click at manuals, then click at its title.

Comments about this recipe

Contributors

-- JensAxelSoegaard - 16 Jan 2005