Yep, that's what he's saying. I know why you're confused. Let me see if I can help.
Here's an input program: '(1 2 3) Now be careful to make the following distinction: - what it computes - what it prints What it computes is a list with three values. There are at least three different ways to PRINT this: 1. (1 2 3) 2. #<list> 3. (quote (1 2 3)) The first has the disadvantage Matthias pointed out: you can't paste the value back in in a bigger computation. The second has the same disadvantage. The third has the advantage you can paste it back in. You're probably concerned that pasting it back in "makes a new list". Yes, it does. But if the expression '(1 2 3) were part of some bigger computation -- eg, (length '(1 2 3)) -- then no "new list" would be created. So it's only if you try copying the output of one computation as the input of another that there might be new allocation. But look at the word I just used: "copy". This isn't the full answer, but I think you need to make sure you've got at least these steps under your belt before we go further. Do ask questions. Shriram _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
