Class: Squeeze::HashTree

Inherits:
Hash
  • Object
show all
Includes:
Traversable
Defined in:
lib/squeeze/hash_tree.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Traversable

#count, #filter, #increment, #reduce, #reducer, #retrieve, #search, #set, #sum, #traverse, #unique

Class Method Details

.[](hash) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 21

def self.[](hash)
  ht = self.new
  ht << hash
  ht
end

._load(*args) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 33

def self._load(*args)
  h = Marshal.load(*args)
  ht = self.new
  ht.replace(h)
  ht
end

.new ⇒ Object

Override the constructor to provide a default_proc NOTE: there’s a better way to do this in >=1.9.2, it seems. See Hash#default_proc=



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# File 'lib/squeeze/hash_tree.rb', line 16

def self.new()
  hash = Hash.new { |h,k| h[k] = HashTree.new }
  super.replace(hash)
end

Instance Method Details

#+(other) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 89

def +(other)
  out = HashTree.new
  _plus(other, out)
  out
end

#<<(other) ⇒ Object

Merge the argument into self, overwriting where necessary.



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# File 'lib/squeeze/hash_tree.rb', line 128

def <<(other)
  other.each do |k,v1|
    if self.has_key?(k)
      v2 = self[k]
      if v1.respond_to?(:has_key?) && v2.respond_to?(:has_key?)
        v2 << v1
      elsif v1.is_a?(Numeric) && v2.is_a?(Numeric)
        self[k] = v1 + v2
      else
        raise ArgumentError,
          "Can't merge leaf with non-leaf:\n#{v1.inspect}\n#{v2.inspect}"
      end
    else
      if v1.respond_to?(:has_key?)
        self[k] << v1
      else
        self[k] = v1
      end
    end
  end
end

#_dump(depth) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 27

def _dump(depth)
  h = Hash[self]
  h.delete_if {|k,v| v.is_a? Proc }
  Marshal.dump(h)
end

#_plus(ht2, out) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 95

def _plus(ht2, out)
  self.each do |k1,v1|
    v1 = v1.respond_to?(:dup) ? v1 : v1.dup
    if ht2.has_key?(k1)
      v2 = ht2[k1]
      if v1.respond_to?(:_plus)
        out[k1] = v1
        v1._plus(v2, out[k1])
      elsif v2.respond_to?(:_plus)
        raise ArgumentError,
          "Can't merge leaf with non-leaf:\n#{v1.inspect}\n#{v2.inspect}"
      else
        if v2.is_a?(Numeric) && v1.is_a?(Numeric)
          out[k1] = v1 + v2
        else
          out[k1] = [v1, ht2[k1]]
        end
      end
    else
      # should anything happen here?
    end
  end
  ht2.each do |k,v|
    if self.has_key?(k)
      # should anything happen here?
    else
      v = v.respond_to?(:dup) ? v : v.dup
      out[k] = v
    end
  end
end

#children(matcher = true) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 82

def children(matcher=true)
  next_keys = self.keys.select do |key|
    match?(matcher, key)
  end
  self.values_at(*next_keys)
end

#create_path(sig) {|hash, final_key| ... } ⇒ Object

Follow the path specified, creating new nodes where necessary. Returns the value at the end of the path. If a block is supplied, it will be called with the last node and the last key as parameters, analogous to Hash.new’s default proc. This is necessary to allow setting a value at the end of the path. See the implementation of #insert.

Yields:

  • (hash, final_key) 


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# File 'lib/squeeze/hash_tree.rb', line 45

def create_path(sig)
  final_key = sig.pop
  hash = self
  sig.each do |a|
    hash = hash[a]
  end
  yield(hash, final_key) if block_given?
  hash[final_key]
end

#each_leaf(stack = [], &block) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 181

def each_leaf(stack=[], &block)
  self.each do |k,v|
    stack.push(k)
    if v.respond_to?(:each_leaf)
      v.each_leaf(stack, &block)
    else
      yield(v)
      #block.call(v)
    end
    stack.pop
  end
end

#each_path(stack = [], &block) ⇒ Object

Depth-first traversal, yielding the path to each leaf.



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# File 'lib/squeeze/hash_tree.rb', line 168

def each_path(stack=[], &block)
  self.each do |k, v|
    stack.push(k)
    if v.respond_to?(:each_path)
      v.each_path(stack, &block)
    else
      yield(stack, v)
      #block.call(stack, v)
    end
    stack.pop
  end
end

#find(sig) ⇒ Object

Attempt to retrieve the value at the end of the path specified, without creating new nodes. Returns nil on failure.



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# File 'lib/squeeze/hash_tree.rb', line 57

def find(sig)
  stage = self
  sig.each do |a|
    if stage.has_key?(a)
      stage = stage[a]
    else
      return nil
    end
  end
  stage
end

#match?(val, key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/squeeze/hash_tree.rb', line 150

def match?(val, key)
  case val
  when true
    true
  when String, Symbol
    key == val
  when Regexp
    key =~ val
  when Proc
    val.call(key)
  when nil
    false
  else
    raise ArgumentError, "Unexpected matcher type: #{val.inspect}"
  end
end

#remove(sig) ⇒ Object 



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# File 'lib/squeeze/hash_tree.rb', line 69

def remove(sig)
  stage = self
  s2 = sig.slice(0..-2)
  s2.each do |a|
    if stage.has_key?(a)
      stage = stage[a]
    else
      return nil
    end
  end
  stage.delete(sig.last)
end