I am reading the “Clojure Programming” book (by Chas Emerick) and something made me intrigued. It mentions the “head retention” problem, with an example. Here’s the example: This apparently causes an OutOfMemoryError: `(let [[t d] (split-with #(< % 12) (range 1e8))] [(count d) (count t)])` While this doesn’t: `(let [[t d] (split-with #(< % 12) (range 1e8))] [(count t) (count d)])` The explanation is: “Since the last reference to t occurs before the processing of d, no reference to the head of the range is kept, and no memory issues arise.” I read this many times and I simply cannot understand the reason why this is happening. Can someone help me to understand this?

Found something on stack overflow -> https://stackoverflow.com/questions/15994316/clojure-head-retention

How can I include all clojure core libraries in a file so I don't have to fully qualify functions (clojure.string/upper-case "string") vs (upper-case "string")

or is that bad practice...

@dannystanny01 (require [clojure.string :refer :all])

Something like this, afaik it’s not a bad practice

Thanks

hi all, pls could you advise how do I use apache derby within a lein project