Yesterday on the reia mailing list Tony asked all of our opinions on indentation sensitivity. This is what we had to say:

This is what he had to say.

So basically python can stick it! Don’t worry, it’s not just because of the ponies

or because it’s a speed demon compared to ruby and we are jealous — it’s just a matter of principle (and developer time). Haml is next in line!

Anyways, what the fuck is Reia anyways? Taken from the wiki, “Reia (pronounced RAY-uh) is a Python/Ruby-like scripting language for the Erlang virtual machine (BEAM).”

What the fuck is erlang?

So why is it cool?? Cause, erlang is considered to be the ONLY language that not only meets concurrent concerns but EXCELS with flying colors on it — too bad the syntax can suck a nut or two…and coupled with the fact that since it’s a functional language with single assignment it doesn’t really fit into the object oriented paradigm that we’ve (20 something and under) have grown up with. Reia adds to the coolness by taking the 9 9′s of uptime, hot-code swapping, 80-core power producing, rampaging code crocodiling that is erlang and allowing us lowly programmers that are not voluntary-bald to kick ass with our time-saving dynamic language, duck typing, BDD, money making Machiavellism.

How do I get down with this madness?

Simple padawan. Let’s start by

installing erlang.

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sudo apt-get install erlang

make sure we have 5.6.3 or greater..

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erl

type q(). to quit

clone reia:

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git clone git://github.com/tarcieri/reia.git
cd reia; rake install; sudo rake install

I spend most of my time in irb so let’s
run ire:

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me@spicetrader:~$ ire
Reia Interactive Shell (prerelease)
Running on Erlang (BEAM) emulator version 5.6.3 [source] [smp:2] [async-threads:0] [kernel-poll:true]

simple.. enough..

let’s hello world this shit up:

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>> puts("hello world")
hello world
=> nil

yes, those parens are necessary for now..

lambda?

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>> pp = fun(str) { puts("#{str} does the limbo dance"); }
=> #
>> pp('ian')
ian does the limbo dance
=> nil
>> pp('kara')
kara does the limbo dance
=> nil

recursion?
for this example let’s use reia’s interpreter: reia..no kidding?!
open up your favorite text editor

vim blah.re

and paste this:

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module Fib
  def calc(1)
    1
  end
 
  def calc(n)
    if (n == 0)
      0
    else
      calc(n - 1) + calc(n - 2)
    end
  end
 
end
 
puts(Fib.calc(3))
puts(Fib.calc(10))

now let's run it:

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me@spicetrader:~$ reia blah.re 
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55

this shows you a couple important things about erlang and reia.
1st: most ppl on the erlang list will shun if/else conditionals
saying there is no need for them when you have pattern
matching and recursion

last but not least we get back to the original point of this article:
reia lost it's indentation sensitivity!!

Thanks Tony!