class Hashery::OpenCascade

OpenCascade is subclass of OpenHash. It differs in a few significant ways. The reason this class is called “cascade” is that every internal Hash is transformed into an OpenCascade dynamically upon access. This makes it easy to create “cascading” references.

h = { :x => { :y => { :z => 1 } } }
c = OpenCascade[h]
c.x.y.z  #=> 1

As soon as you access a node it automatically becomes an OpenCascade.

c = OpenCascade.new   #=> #<OpenCascade:0x7fac3680ccf0 {}>
c.r                   #=> #<OpenCascade:0x7fac368084c0 {}>
c.a.b                 #=> #<OpenCascade:0x7fac3680a4f0 {}>

But if you set a node, then that will be that value.

c.a.b = 4             #=> 4

To query a node without causing the auto-creation of an OpenCasade instance, use the ‘?`-mark.

c.a.z?                #=> nil

OpenCascade also transforms Hashes within Arrays.

h = { :x=>[ {:a=>1}, {:a=>2} ], :y=>1 }
c = OpenCascade[h]
c.x.first.a.assert == 1
c.x.last.a.assert  == 2

Finally, you can set call a private method via bang methods using the ‘!`-mark.

c = OpenCascade.new   #=> #<OpenCascade:0x7fac3680ccf0 {}>
c.each = 4
c.each! do |k,v|
  ...
end

c.x!(4).y!(3)         #=> #<OpenCascade:0x7fac3680ccf0 {:x=>4, :y=>3}>

Subclassing OpenCascade with cause the new subclass to become the class that is auto-created. If this is not the behavior desired, consider using delegation instead of subclassing.

Public Class Methods

new(*default) click to toggle source

Initialize new OpenCascade instance.

default - The usual default object.

Calls superclass method
# File lib/hashery/open_cascade.rb, line 64
def initialize(*default)
  @read = {}

  leet = lambda { |h,k| h[k] = self.class.new(&leet) }
  super(*default, &leet)
end

Public Instance Methods

method_missing(sym, *args, &blk) click to toggle source
# File lib/hashery/open_cascade.rb, line 95
def method_missing(sym, *args, &blk)
  type = sym.to_s[-1,1]
  name = sym.to_s.gsub(/[=!?]$/, '').to_sym

  case type
  when '='
    store(name, args.first)
  when '?'
    key?(name) ? retrieve!(name) : nil    # key?(name)
  when '!'
    __send__(name, *args, &blk)
  else
    #if key?(name)
      retrieve(name)
    #else
    #  #default = OpenCascade.new #self.class.new
    #  #default = default_proc ? default_proc.call(self, name) : default
    #  store(name, read(name))
    #end
  end
end
respond_to?(sym, include_private = false) click to toggle source
Calls superclass method
# File lib/hashery/open_cascade.rb, line 117
def respond_to?(sym, include_private = false)
  sym != :to_ary && super
end
retrieve(key) click to toggle source

Read value given a key.

key - Index key to lookup.

Returns value.

Calls superclass method
# File lib/hashery/open_cascade.rb, line 83
def retrieve(key)
  ckey = cast_key(key)
  if @read[ckey]
    super(key)
  else
    @read[ckey] = store(key, cast_value(super(key)))
  end
end
Also aliased as: retrieve!
retrieve!(key)

Alias for original read method.

Alias for: retrieve

Private Instance Methods

cast_value(entry) click to toggle source

Cast value, such that Hashes are converted to OpenCascades. And Hashes in Arrays are converted to OpenCascades as well.

# File lib/hashery/open_cascade.rb, line 133
def cast_value(entry)
  case entry
  when Hash
    e = OpenCascade.new
    e.key_proc = key_proc if key_proc
    e.merge!(entry)
    e
  when Array
    entry.map{ |e| cast_value(e) }
  else
    entry
  end
end