[plt-scheme] Help with understanding how to reuse macro data

From: Geoffrey S. Knauth (geoff at knauth.org)
Date: Sat Jan 3 17:58:53 EST 2009

On Jan 3, 2009, at 17:03, Joe Marshall wrote to Grant Rettke:
> Here's the logic behind my opinion.  In your example, you are  
> manipulating `means to open safes'.  You have primitives like `try  
> this combination' and `ask Vinnie', and means of combination like  
> `first try primitive1, then try primitive2'.  Now, given several  
> primitives and some combinators, you want to reason about strategy.   
> It seems to me that your primitives and combinators should be first- 
> class objects.  You want to bind them to variables, make lists of  
> them, put them together and take them apart, etc.
> Macros, however, aren't designed for this sort of thing.  A macro  
> isn't a first-class object.  You are using the macro only to parse  
> the list representation of *one* of the primitive means to open a  
> safe.  A parsing library would get you further, and you wouldn't be  
> limited by requiring that the list representation appear as a  
> literalin the code.

Maybe there is a use for macros in the artificial safe-cracking  
scheme.  Macros could be used to deceive the user.  Instead of asking  
Vinnie or just trying a combination, bindings could be manipulated and  
code replaced to send Vinnie's advice or working combinations to an  
untrusted third party.


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