The rule of thumb I used when I started with Clojure was if I'm
tempted to use a def inside a function, I'm doing something wrong.
Now, I'm not even tempted.
(def mut-local)
(defn f []
(binding [mut-local 0]
(set! mut-local 1)
mut-local))
Is the same as what you wrote.
Functional programming is a totally different mind set than imperative
programming. You might pick up "The Little Schemer" and "The Seasoned
Schemer". They do a good job of changing your perspective.
Jim
On Dec 1, 2:55 pm, puzzler <[EMAIL PROTECTED]> wrote:
> I'm often copying "classic algorithms" from various sources, and it is
> true that it can take some thought to do a functional conversion.
> Sometimes, it's easier to just go ahead and use mutable local
> variables. Fortunately, Clojure lets you do mutability if needed.
>
> But I'm still unclear on the best way to do that. To simulate mutable
> locals, would you use refs or vars? My own instinct would be to use
> vars for a temporary mutable local, and refs for something that the
> closure has to remember (like memoization).
>
> Here's how I think you could do a mutable local:
> (defn f []
> (def mut-local)
> (binding [mut-local 0]
> (set! mut-local 1)
> mut-local))
>
> (f) should yield 1
>
> The flaw with this approach is that def actually creates a global
> var. It remains unbound, but the fact that the function ends up
> having a global effect is less than satisfying.
>
> Better ways?
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