Comments on: Simple SparkLine Generator in Clojure

By: Michael Mellinger

Michael Mellinger — Wed, 02 Sep 2009 13:14:59 +0000

Diff file:
—————————————-
30,33c30,33
< (do (doto g (setColor (. java.awt.Color white))
< (fillRect 0 0 w h)
< (setColor (. java.awt.Color gray)))
(do (doto g (.setColor (. java.awt.Color white))
> (.fillRect 0 0 w h)
> (.setColor (. java.awt.Color gray)))
> (dotimes [idx (dec (count v))]
43,44c43,44
< (doto g (setColor (. java.awt.Color red))
(doto g (.setColor (. java.awt.Color red))
> (.fillOval bx by 2 2))))
57,59c57,59
< (add (new javax.swing.JLabel icon))
< (pack)
(.add (new javax.swing.JLabel icon))
> (.pack)
> (.setVisible true))))

By: Aron

Aron — Sat, 21 Mar 2009 23:11:49 +0000

Hi. Thanks for writing this sample code. I ran into two problems running sparklines.clj as written (against clojure-20090320).

1. Calls against Java objects within (doto ..) needed to be .method.
(setColor …) -> (.setColor …)
Changed: setColor, fillRect, fillOval, add, pack, setVisible

2. dotimes takes a vector.
(dotimes idx (count v) …)
becomes
(dotimes [idx (dec (count v))] …)
The (dec …) was necessary to avoid an out-of-bounds index exception from:
this-val (nth v (inc idx))
on the last iteration.

By: Gavin

Gavin — Wed, 07 Jan 2009 23:21:37 +0000

Cool. Good to see some well-written example code out there to learn from.

One thing I noticed is that it was written before the Java interop macros were implemented. You could shorted probably every s-exp containing Java. E.g. (. bitmap (getGraphics)) –> (.getGraphics bitmap)

Whether it’s worthwhile is up to you.

By: newlisper

newlisper — Fri, 29 Feb 2008 23:28:10 +0000

Nice - I’ve only seen a few positive references to Clojure, and it looks fascinating. It’s interesting to see the way you mix Lisp and Java together - even if the class names look a bit scary.

You might be interested to see the sparkline generator I did. I only saw your version after I did mine, so I may be able to improve my code after seeing yours.

Will have to look at Clojure soon.

By: hitesh

hitesh — Fri, 29 Feb 2008 06:43:03 +0000

Nice. I like the Lispishness of Clojure. It might be something I’d consider if I had to write code running on the JVM.

By: Rich Hickey

Rich Hickey — Thu, 28 Feb 2008 14:54:09 +0000

You might want to try destructuring in let:

(let [{w :width h :height v :values} data] …