trlinkin/hashlib

Utility methods for Ruby Hashes

Hashlib: Utility methods for Ruby Hashes

Hashlib extends the base Ruby Hash class with new methods that offer useful functionality for working with hashes, specifically addressing handling of deeply-nested Hashes for representing rich object structures.

get

The get method is used to allow for retrieval of a deeply-nested value in a hash structure.

Given:

config = {
  :global => {
    :security => {
      :sslroot => '/etc/ssl'
    },
    :pidfile => '/var/run/example.pid'
  },
  :plugins => ['logger', 'cruncher']
}

The following statements are equivalent:

config.get('global.security.sslroot')

# returns the same thing as

config[:global][:security][:sslroot]

However, let's say you attempted to get config[:global][:adapters][:path]. You would get a nasty NilError because :adapters doesn't exist. However, if you used config.get('global.adapters.path'), the result would just be nil. get also takes a second argument that let's you specify the default value if the given path is not found. This lets you very easily work with rich nested hashes while also specifying sane defaults for missing values.

set

The set method is the opposite of get. It creates one or more intermediary hashes along a specified path and setting the value for the last component.

y = {}
y.set('this.is.a.number', 4)

# results in
# {"this"=>{
#    "is"=>{
#      "a"=>{
#        "number"=>4
# }}}}