[plt-scheme] to define, or to let

======= 2004-03-19 09:07:17 ：=======

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>I messed up the question; the final expressions should be:
>(list one-variable another-variable)
>
>So what is the difference in the generated code?  Are let-variables 
>created differently than define's ?  It seems that a smart compiler 
>wouldn't create storage at all in the let version (ie, it would just 
>form the list).
>
>rac
>
= = = = = = = = = = = = = = = = = = = =
			
Yes, a smart compiler will treat let without creating storage. 

For example:

(let ((one-variable 3)
      (another-variable 4))
  (list one-variable another-variable))

will first be converted to

((lambda (one-variable another-variable)
   (list one-variable another-variable))
 3 4)

and then the code will be further optimized to 

(list 3 4)


regards, 
Zhu Chongkai