killme2008 / local.var

Local transient var for clojure.

local.var

Local-transient var for clojswap!ure.

A local-transient var is just a local value holder which is mutable,and it's value can be updated by functions, it is not synchronized, so it can' be accessed concurrently.

Usage

Install it in leiningen:

[local.var "0.1.0"]

(require '[local.var :refer [transient-var! ltv-reset! ltv-swap! transient-var?]])

(let [sent (transient-var! false)]
	;;send emails to client
	;;......
	(ltv-reset! sent true)
	(if @sent
	    (println "Sent email successfully!")
	    (println "Sent email failed.")))	    
	    

Create a local-transient var:

(def x (transient-var! 1))

Get value in it:

@x         ;; => 1
(deref x)  ;; => 1

Reset it's value:

(ltv-reset! x 99) ;; => 99
@x                ;; => 99

Update it's value with function and (optional) arguments:

(ltv-swap! x inc)   ;; => 100
(ltv-swap! x + 100) ;; => 200 

Check if a var is a local-transient var:

(transient-var? x)  ;; => true
(transient-var? 1)  ;; => false

Every local-transient var has an owner thread that creates it, if you want to modify it in other thread, it will throw an error:

@(future (ltv-reset! x 100))   ;; =>  IllegalAccessError Local transient var used by 
                               ;;     non-owner thread  local.var/ltv-reset!

License

Copyright © 2016 FIXME

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.