Module: KVDAG::AttributeNode

Included in:
Edge, Vertex
Defined in:
lib/kvdag/attrnode.rb

Overview

Mixin with common methods for managing the attrs of vertices and edges in a KVDAG.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#attrs ⇒ Object (readonly)

Returns the value of attribute attrs.



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# File 'lib/kvdag/attrnode.rb', line 6

def attrs
  @attrs
end

Instance Method Details

#[](attr, options = {}) ⇒ Object

Return the value for an attr, or nil if the attr can’t be found.

options:

shallow

If true, lookup is limited to attrs defined in this attrnode. The default is lookup in the tree returned by to_hash_proxy.



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# File 'lib/kvdag/attrnode.rb', line 34

def [](attr, options = {})
  fetch(attr, options)
rescue
  nil
end

#[]=(attr, value) ⇒ Object

Set the value for an attr in this attrnode.



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# File 'lib/kvdag/attrnode.rb', line 42

def []=(attr, value)
  @attrs[attr] = value
end

#fetch(attr, options = {}) ⇒ Object

Returns the value for an attr. If the attr can’t be found, it will raise a KeyError exception.

options:

shallow

If true, lookup is limited to attrs defined in this attrnode. The default is lookup in the tree returned by to_hash_proxy.



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# File 'lib/kvdag/attrnode.rb', line 16

def fetch(attr, options = {})
  case
  when (options[:shallow])
    @attrs.fetch(attr)
  when self.respond_to?(:to_hash_proxy)
    to_hash_proxy.fetch(attr)
  else
    to_hash.fetch(attr)
  end
end

#filter(*keys) ⇒ Object

Filter the key-value view of a vertex by a list of key prefixes, and return a hash_proxy containing only those trees.

:call-seq:

filter("key.path1", ..., "key.pathN") -> hash_proxy



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# File 'lib/kvdag/attrnode.rb', line 65

def filter(*keys)
  if self.respond_to?(:to_hash_proxy) then
    to_hash_proxy.filter(*keys)
  else
    raise NotImplementedError.new('not implemented for plain hash')
  end
end

#match?(filter = {}) ⇒ Boolean

:call-seq:

match?()                           -> true
match?(method: match, ...)         -> true or false
match?(one?:{ matches }, ...)      -> true or false
match?(any?:{ matches }, ...)      -> true or false
match?(all?:{ matches }, ...)      -> true of false
match?(none?:{ matches }, ...)     -> true or false

Checks if the key-value view visible from a node matches all of set of filters. An empty filter set is considered a match.

Any method given will be matched against its result:

match === self.send(method)

matches should be a hash with ‘key.path’ strings at keys, and match values to check for equality:

match === self[key]

Examples:

node.match?(class:KVDAG::Vertex)
node.match?(none?:{'key' => Integer})
node.match?(all?:{'key' => /this|that/})
node.match?(any?:{'key1' => 'this', 'key2' => 'that'})
node.match?(one?:{'key1' => 'this', 'key2' => 'that'})

Returns:

  • (Boolean) 


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# File 'lib/kvdag/attrnode.rb', line 99

def match?(filter = {})
  valid_enumerators = [:none?, :one?, :any?, :all?]

  filter.all? do |item|
    method, match = item
    if valid_enumerators.include?(method)
      match.send(method) do |match_item|
        key, value = match_item
        value === self[key]
      end
    else
      match === self.send(method)
    end
  end
end

#merge!(other) ⇒ Object 



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# File 'lib/kvdag/attrnode.rb', line 54

def merge!(other)
  @attrs.merge!(other.to_hash)
  self
end

#to_hash ⇒ Object 



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# File 'lib/kvdag/attrnode.rb', line 46

def to_hash
  if self.respond_to?(:to_hash_proxy) then
    to_hash_proxy.to_hash
  else
    @attrs
  end
end