[racket] why zip and base64 encode an algol60 module?

I was looking at the Algol 60 code while looking at use of the tool phases,
and found this  (prefix bd: "bd-tool.ss")).

What surprised me was that is pointed to this:


#lang s-exp framework/private/decode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which gets deflated and unencoded into a module, (AFAICT) via;

#lang scheme/base
(require (for-syntax scheme/base file/gunzip net/base64))
(provide (except-out (all-from-out scheme/base) #%module-begin)
         (rename-out [module-begin #%module-begin]))

(define-syntax (module-begin stx)
  (syntax-case stx ()
    [(_ x ...)
     (andmap (lambda (x) (or (identifier? x) (integer? (syntax-e x))))
             (syntax->list #'(x ...)))
     (let* ([data  (format "~a" (syntax->datum #'(x ...)))]
            [data  (substring data 1 (sub1 (string-length data)))]
            [data  (string->bytes/utf-8 data)]
            [in    (open-input-bytes (base64-decode data))]
            [out   (open-output-string)]
            [out   (begin (inflate in out) (get-output-string out))]
            [exprs (read (open-input-string (string-append "(" out ")")))]
            [exprs (datum->syntax stx exprs stx)])
       #`(#%module-begin #, at exprs))]))


Why is this done?

Cheers,

Stephen




-- 

--
Stephen De Gabrielle
stephen.degabrielle at acm.org
Telephone +44 (0)20 85670911
Mobile        +44 (0)79 85189045
http://www.degabrielle.name/stephen
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