Thanks so much for your help!!! I'm so glad you had the time to
respond to my newbie question.
And as if you read my mind as I was going through the SICP lecture and
referencing chapter two in Manning's Joy of Clojure book I was
wondering how to turn this explicit recursive call taken from the
Glad I could help! SICP is a wonderful book, and Clojure is a dream
come true in that it gives you a step from SICP into the real world.
Clojure would be just about perfect if it had general tail call
optimization and continuations, but I don't really miss those so far
(in any case they can't
Hi All,
I'm watching Brian Harvey's SICP lecture #3 from Berkeley 61A/Spring
2011 and had a question about how I could refactor the following
function so that the (+a 1) can be abstracted to be a function and
passed in.
Here is the original:
(defn square [x] (* x x))
(defn sum [fn a b]
(if
All you have to do is abstract the function you want (by 'abstract' I
mean put it in the argument list and replace the function with the
variable):
(defn sum2 [func incr a b]
(if ( a b)
0
(+ (fn a) (sum2 func incr (incr a) b
You wouldn't want to use this code in the real world
Another solution, this time using Clojure's tail recursion:
(defn sum2 [func incr a b]
(loop [accum 0
x a]
(if ( x b)
accum
(recur (+ (func x) accum) (incr x)
This may be getting ahead of where you are now, so come back and look
when you've covered map, reduce, and
