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Re: memoization and conditional defines
From: |
Lynn Winebarger |
Subject: |
Re: memoization and conditional defines |
Date: |
Thu, 7 Nov 2002 18:22:03 -0500 |
On Thursday 07 November 2002 14:08, Bruce Korb wrote:
> I don't care how memoization works. I understand there are
> optimization issues. Optimizing isn't important to me, or
> I would not use an interpretive language as my "extension
> language".
It's really about correctness of macro expansion in a broader
sense than just the core macros ('lambda, 'define, etc). The core
macros just transform the sexpression into a more explicit parse
tree. If you didn't do that, you could never be sure whether your
function would actually be a function or not. The symbol 'lambda
can be redefined at will by code in R5RS. There are no
reserved keywords.
> BTW, my guess is that memoizing Guile will make it go much slower.
Guile has been memoizing since its creation (or rather, the creation
of SCM).
If you're worried about (if <test> (define <foo> <bar>)), you
can always use
(if <test> (eval '(define <foo> <bar>)))
which will do what you want. eval's always execute in a top-level environment,
no matter where the expression occurs in the code. And that '(define <foo>
<bar>)
would get re-expanded every time it got executed.
Lynn
Re: memoization and conditional defines, Rob Browning, 2002/11/07
Re: memoization and conditional defines, Marius Vollmer, 2002/11/17