git clone ''

(ql:quickload :cl-hash-util)


cl-hash-util is a very basic library for dealing with CL's hash tables. The idea was spawned through working with enough JSON APIs and config files, causing a lot of headaches in the process. For instance, to get a value deep within a hash, you have to do: common-lisp (gethash "city" (gethash "location" (gethash "user" obj)))

I find the inside-out approach unintuitive, regardless of how many lisp nerds are going to yell at me about how it's correct.

With cl-hash-util, you can write:

(hash-get obj '("user" "location" "city"))

hash-get can also deal with getting elements out of lists and arrays:

(hash-get obj '("user" "friends" 0 "name"))

which normally would have to be written as such:

(gethash "name" (elt (gethash "friends" (gethash "user" obj)) 0))


cl-hash-util also provides an easy way to build hash tables on the fly. Where you'd normally have to do something like:

(let ((myhash (make-hash-table :test #'equal)))
  (setf (gethash "name" myhash) "andrew")
  (setf (gethash "location" myhash) "santa cruz")

You can now do:

;; functional version
(hash-create '(("name" "andrew") ("location" "santa cruz")))

;; convenience macro `hash`
(hash ("name" "andrew") ("location" "santa cruz"))

You can also do nested hashes: common-lisp (hash ("name" "andrew") ("location" (hash ("city" "santa cruz") ("state" "CA"))))

This saves a lot of typing =].