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Internet Message Format  |  2002-01-03  |  3KB
  1. Return-Path: <icon-group-sender>
  2. Received: (from root@localhost)
  3.     by baskerville.CS.Arizona.EDU (8.11.1/8.11.1) id f65FxDw19347
  4.     for icon-group-addresses; Thu, 5 Jul 2001 08:59:13 -0700 (MST)
  5. Message-Id: <200107051559.f65FxDw19347@baskerville.CS.Arizona.EDU>
  6. From: Chris.D.Tenaglia@jci.com
  7. Subject: Re: Software testing for Icon?
  8. To: art.eschenlauer@sufsys.com
  9. Cc: icon-group@cs.arizona.edu
  10. Date: Thu, 5 Jul 2001 09:06:57 -0500
  11. X-MIMETrack: Serialize by Router on jwimkrs1.na.jci.com/NA/Johnson_Controls(Release 5.0.6a
  12.  |January 17, 2001) at 07/05/2001 09:25:08 AM
  13. Errors-To: icon-group-errors@cs.arizona.edu
  14. Status: RO
  15. Content-Length: 2353
  16.  
  17. This is probably because the variables are not typed. The data
  18. in the variables and the operation on the variables indicates the
  19. type.
  20.  
  21. procedure example(arg1,arg2,arg3)
  22.  
  23. arg1, arg2, and arg3 could be any type. The emphasis shifts from
  24. the compiler to programmer. But this issue has never surfaced in companies
  25. I've been at. Their usual anti-icon argument is that it's not supported
  26. by Sun, HP, or Compaq in our software support contracts. So we're locked
  27. into VMS DCL or Posix shell script. I can justify icon in rare cases when
  28. a scripting solution becomes huge and convoluted, or using Xwindows,
  29. or it implements much better with set() algorythms.
  30.  
  31. Chris Tenaglia, technical analyst, Johnson Controls
  32.  
  33.  
  34.  
  35.                                                                                                                   
  36.                     art.eschenlauer@                                                                              
  37.                     sufsys.com              To:     icon-group@CS.Arizona.EDU                                     
  38.                                             cc:                                                                   
  39.                     06/25/01 11:33          Subject:     Software testing for Icon?                               
  40.                     AM                                                                                            
  41.                                                                                                                   
  42.                                                                                                                   
  43.  
  44.  
  45.  
  46.  
  47. One concern that I expect people to raise with respect to using Icon in the
  48. "mainstream" is, "Icon cannot be trusted because it does not typecheck
  49. arguments at compile time.  How can you protect against programmer errors
  50. in
  51. the arguments passed during infrequently-executed invocations?"  I don't
  52. think that the response (however true) that C++ has compile-time
  53. type-checking and yet still is notorious for null pointer errors, etc, will
  54. convince anybody.
  55.  
  56. This raises two questions in my mind regarding Icon:
  57.  
  58. 1. Should one adopt a "defensive programming style", always checking the
  59. arguments passed to each routine?
  60.  
  61. 2. What work has been done on developing rigorous software-testing
  62. methodology for Icon programs?
  63.  
  64.  
  65.  
  66.  
  67.