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  1.  
  2. (define cwd (make-parameter "/home"))
  3.  
  4. (define (foo x)
  5. 	(displayln (cwd))
  6. 	(displayln x))
  7.  
  8. (define-syntax-rule (bar d body)
  9. 	(parameterize [(cwd (string-append (cwd) "/" d))]
  10. 		(begin body)))
  11.  
  12.  
  13. (foo 12)
  14. (bar "myuser"
  15. 	(begin
  16.    (foo 12)
  17. 	  (bar "another_dir"
  18. 		  (foo 14))))
Success #stdin #stdout 0.43s 70780KB
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stdin
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Standard input is empty
stdout
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/home
12
/home/myuser
12
/home/myuser/another_dir
14
https://ideone.com/W11UFB
language:
Racket (racket 7.0)
created:
4 years ago
visibility:
public

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