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Name	Size	Permission
applique	[ DIR ]	drwxr-xr-x
00_introduction.rdoc	159 B	-rw-r--r--
01_open_hash.rdoc	1.62 KB	-rw-r--r--
02_query_hash.rdoc	402 B	-rw-r--r--
03_casting_hash.rdoc	260 B	-rw-r--r--
04_static_hash.rdoc	385 B	-rw-r--r--
05_key_hash.rdoc	376 B	-rw-r--r--
06_open_cascade.rdoc	1.49 KB	-rw-r--r--
07_fuzzy_hash.rdoc	2.9 KB	-rw-r--r--
08_propery_hash.rdoc	715 B	-rw-r--r--
10_association.rdoc	1.17 KB	-rw-r--r--

Code Editor : 10_association.rdoc

= Association

An Association is a class for creating simple pairings.

require 'hashery/association'

An Association can bew created through the usual means 
of instantiation.

Association.new(:a, :b)

Or the shortcut method #>> can be used in most cases.

:x >> :z

An association provides two methods to access its content, #index and #value.

a = 'foo' >> 'bar'

a.index.assert == 'foo'
    a.value.assert == 'bar'

Associations can be used to create ordered-hashes via normal
arrays.

keys = []
    vals = []

ohash = [ 'A' >> '3', 'B' >> '2', 'C' >> '1' ]

ohash.each{ |k,v| keys << k ; vals << v }

keys.assert == ['A','B','C']
    vals.assert == ['3','2','1']

Becuase Associations are objects in themselves more complex
collections can also be created.

complex = [
      'parent' >> 'child',
      'childless',
      'another_parent' >> [
        'subchildless',
        'subparent' >> 'subchild'
      ]
    ]

An experimental feature of Association keeps a cache of all defined associations.

o = Object.new
    o >> :a
    o >> :b
    o >> :c

o.associations.assert == [:a, :b, :c]

However this feature will probably be deprecated.

${this.title}

Code Editor : 10_association.rdoc