Octothorpe

A very simple hash-like class that borrows a little from OpenStruct, HashWithIndifferentAccess, etc.

• Treats string and symbol keys as equal
• Access member objects with ot.>>.keyname
• Guard conditions allow you to control what returns if key is not present
• Pretty much read-only, for better or worse

Meant to facilitate message-passing between classes.

Installation

Add this line to your application's Gemfile:

gem 'octothorpe'

And then execute:

$ bundle

Or install it yourself as:

$ gem install octothorpe

Usage

Simple example:

ot = Octothorpe.new(one: 1, "two" => 2, "weird key" => 3)
ot.>>.one            # -> 1
ot.>>.two            # -> 2
ot.get("weird key")  # -> 3

With guard conditions:

ot = Octothorpe.new(one: 1, "two" => 2)
ot.guard(Array, :three)
ot.freeze       # optional step - makes OT truly read-only
ot.>>.three     # -> [] 
ot.>>.three[9]  # valid (of course; returns nil)

Octothorpe responds to a good subset of the methods that hash does (although, not the write methods).

FAQ

Octo-what?

An antiquated term for the pound, or, hash key on a phone keyboard. It's a sort of a joke, you see. Or, very nearly.

This is a very small library. Was it really worth it?

Maybe not. Feel free to be your own judge.

What possible use is it?

Well, I use it to pass data between models, controllers and views in Sinatra.

If you are fed up with errors caused because Gem A gives you a hash with string keys and Gem B expects symbol keys; or you are tired of putting:

hash && (hash[:key] || {})[4]

... and for some reason Ruby's new lonely operator is a problem, then this might just possibly be of use.

Alternatively you might try a Struct. (Really, if you can use a Struct, then that would be better). Or an OpenStruct, Rails' HashWithIndifferentAccess, or the Hashie gem.

Why Read-Only?

Functional programming.

I find it very hard to fully realise the ideals of functional programming in Ruby; but as I get closer to those ideals, my code becomes clearer to read and my tests become much, much simpler.