Class: KVDAG::KeyPathHashProxy

Inherits:
Hash
  • Object
show all
Defined in:
lib/kvdag/keypathhash.rb

Defined Under Namespace

Classes: KeyPath

Instance Method Summary collapse

Constructor Details

#initialize(hash = {}) ⇒ KeyPathHashProxy

Returns a new instance of KeyPathHashProxy.

Raises:

  • (TypeError) 


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# File 'lib/kvdag/keypathhash.rb', line 15

def initialize(hash = {})
  raise TypeError.new("Must be initialized with a `hash`") unless hash.is_a?(Hash)
  @hash = hash.deep_stringify_keys
  super(@hash)
end

Instance Method Details

#[](keypath) ⇒ Object

:call-seq:

[]("key.path")      -> value or nil
[](["key", "path"]) -> value or nil

Return the value at a specified keypath. If the keypath does not specify a terminal value, return the remaining subtree instead.

Returns nil if the keypath is not found.



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# File 'lib/kvdag/keypathhash.rb', line 60

def [](keypath)
  fetch(keypath)
rescue
  nil
end

#[]=(keypath, value) ⇒ Object 



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# File 'lib/kvdag/keypathhash.rb', line 66

def []=(keypath, value)
  *keypath, key = KeyPath.new(keypath)

  if keypath.empty? then
    hash = @hash
  else
    if not hash = self[keypath] then
      self[keypath] = hash = Hash.new
    end
  end

  hash[key] = value
end

#fetch(keypath) ⇒ Object

:call-seq:

fetch("key.path")      -> value or KeyError
fetch(["key", "path"]) -> value or KeyError

Return the value at a specified keypath. If the keypath does not specify a terminal value, return the remaining subtree instead.

Raises a KeyError exception if the keypath is not found.



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# File 'lib/kvdag/keypathhash.rb', line 40

def fetch(keypath)
  *keysubpath, key = KeyPath.new(keypath)
  hash = @hash

  keysubpath.each {|key| hash = hash.fetch(key)}
  hash.fetch(key)
rescue KeyError
  raise KeyError.new("keypath not found: #{keypath.inspect}")
end

#filter(*keypaths) ⇒ Object

:call-seq:

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

Filter a keypathhash tree by a list of keypath prefixes, and return a new keypathhash containing only those trees.

Raises a KeyError exception if any of the specified keypaths cannot be found.



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# File 'lib/kvdag/keypathhash.rb', line 89

def filter(*keypaths)
  result = self.class.new
  keypaths.each do |keypath|
    result[keypath] = self.fetch(keypath)
  end
  result
end

#merge(other, &block) ⇒ Object 



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# File 'lib/kvdag/keypathhash.rb', line 21

def merge(other, &block)
  self.class.new(@hash.deep_merge(other.deep_stringify_keys, &block))
end

#merge!(other, &block) ⇒ Object 



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# File 'lib/kvdag/keypathhash.rb', line 25

def merge!(other, &block)
  @hash.deep_merge!(other.deep_stringify_keys, &block)
  self
end