Setting up Clojure 1.1.0 on Mac OSX

As part of the Lambda Lounge, established by Alex Miller (Thanks!!), we have started a group to study the SICP. We just started and are going virtual... if you would like to participate, email or tweet me (@kensipe). In the process of studying SICP and LISP, I plan on focusing on Clojure. Clojure was previously on my machine as I was reading Stu's book Programming Clojure, however increased usage would require some maturing of my tools. This led to the discovery of Mark Reid's blog on Setting up Clojure for Mac OS X, however I assume based on updates and changes over the last year, it requires some updates.

Read Mark's blog first... getting clojure, the clojure-contrib and jline. Here are the differences:

• Create an environment variable CLOJURE_HOME assigned to the directory for clojure
• Create the /bin directory for the clj script included below
• Add $CLOJURE_HOME/bin in the $PATH
• Clojure is distributed with clojure.jar in the CLOJURE_HOME... so I maintain that. It is expected that contrib and jline are in the same directory.
• Mark's clj script has been updated below... The previous script invokes classes which are depreciated.
  

Here is the updated script:

#!/bin/bash
# Runs Clojure using the classpath specified in the `.clojure` file of the
# current directory.
#
# Ken Sipe   2010-02-20
# Inspired by Mark Reid 
# original: http://github.com/mreid/clojure-framework/blob/e1c80cc650f448713243be8272dba1fa3c1a7cea/clj
#
# This scripts expects $JAVA_HOME and $CLOJURE_HOME to be defined for the system it is running on
# The clojure.jar is standardly in the clojure_home dir (and not in the lib directory), so
# the expectation is that clojure-contrib.jar and the jline.jar are placed in the same dir

CLJ_DIR=$CLOJURE_HOME
CLOJURE=$CLJ_DIR/clojure.jar
CONTRIB=$CLJ_DIR/clojure-contrib.jar
JLINE=$CLJ_DIR/jline-0_9_5.jar
CP=$PWD:$CLOJURE:$JLINE:$CONTRIB

# Add extra jars as specified by `.clojure` file
if [ -f .clojure ]
then
   CP=$CP:`cat .clojure`
fi

if [ -z "$1" ]; then
   java -server -cp $CP \
        jline.ConsoleRunner clojure.lang.Repl
else
   java -server -cp $CP clojure.main -i $*
fi

Love the TextMate support and the history support in JLine!

Justification for Functional Programming

It appears that this subject has caught fire in recent years. The interest in St. Louis has resulting in the Lamdba Lounge started by Alex Miller. (Great name by the way). I have started reading (but not finished) Programming Clojure by Stuart Halloway and Programming Scala by Venkat Subramaniam. Additionally I just finshed writing a 10 page article on an introduction to functional programming, which includes 4-5 page on F#. The article is for NFJS who holds the exclusive rights at this time, but I plan to provide a link to it or post it here in its entirity after 90 days.

I should point out that I am no expert in this space, but I have been developing professional for 15+ years with a variety of languages (C, C++, Java, C#, a little Ruby, Perl, Groovy). In the last 6 months I've been "playing" with Scala, Clojure and F#.

The reason for this post is this: http://groovy.dzone.com/news/why-functional-programming. This article has been sent to me a couple of times and has been on twitter several. At this point I will make public comments I made in an email response regarding this subject. The first two subjects were points made via email, which make sense to maintain for this blog post.

The Argument to have UI and DB Support
I don't get the ui / db argument. This indicates an all or nothing mentality, which I would hope the industry could get over. A griffon front-end to a java hibernate db access and clojure rules engine make sense to me. Many of the functional languages provide the ability to produce a UI or interact with the DB, however that isn't really important to me as you will see below, but there are good solutions out there where this isn't really a concern.

Functional Notations and Code Beauty
I may be in the minority... but I could care less for "beauty" of code, I'm interested in less code that adds the same or more value. FP adds several notations that provide a conciseness to code, which is a huge value add. As I was writing up an article on F#... I became frustrated with my other programming languages... for instance: why is a switch in Java/Groovy so limiting. Groovy makes it better... but it is still limiting as you compare it to discriminated unions and pattern matching F#.

Getting Functional Programming
People don't get it yet (referring to the nah sayers)... they are in the battle pits and are lacking the big picture vision. This year quad core laptops are expected to be more common. That trend isn't going to stop. The last decade was all about die size and memory. This next decade is all about cores. The need for concurrency tools is a must. The language trend may be slightly ahead of its time.

I'll post more on this subject in the future... I just felt it necessary to provide some response to the value of functional programming. Frankly I've barely scratch the surface of the value.