Class: Puppet::Pops::MergeStrategy

Inherits:
Object
  • Object
show all
Defined in:
lib/puppet/pops/merge_strategy.rb

Overview

Merges to objects into one based on an implemented strategy.

Constant Summary collapse

TypeAsserter = 
Puppet::Pops::Types::TypeAsserter
TypeParser = 
Puppet::Pops::Types::TypeParser

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ MergeStrategy

Create a new instance of this strategy configured with the given options

Parameters:

  • merge_options (Hash<String,Object>) —

    Merge options



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# File 'lib/puppet/pops/merge_strategy.rb', line 80

def initialize(options)
  assert_type('merge_options', options_t, options)
  @options = options
end

Class Method Details

.add_strategy(strategy_class) ⇒ Object

Adds a new merge strategy to the map of strategies known to this class

Parameters:



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# File 'lib/puppet/pops/merge_strategy.rb', line 56

def self.add_strategy(strategy_class)
  unless MergeStrategy > strategy_class
    raise ArgumentError, "MergeStrategies.add_strategy 'strategy_class' must be a 'MergeStrategy' class. Got #{strategy_class}"
  end
  strategies[strategy_class.key] = strategy_class
  nil
end

.key ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/puppet/pops/merge_strategy.rb', line 74

def self.key
  raise NotImplementedError, "Subclass must implement 'key'"
end

.merge(e1, e2, merge) ⇒ Object

Finds a merge strategy that corresponds to the given merge argument and delegates the task of merging the elements of e1 and e2 to it.

Parameters:

  • e1 (Object) —

    The first element

  • e2 (Object) —

    The second element

Returns:

  • (Object) —

    The result of the merge



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# File 'lib/puppet/pops/merge_strategy.rb', line 70

def self.merge(e1, e2, merge)
  strategy(merge).merge(e1, e2)
end

.strategy(merge) ⇒ MergeStrategy

Finds the merge strategy for the given merge, creates an instance of it and returns that instance.

Parameters:

  • merge (String|Symbol|Hash<String,Object>) —

    The merge strategy. Can be a string or symbol denoting the key identifier or a hash with options where the key ‘strategy’ denotes the key

Returns:

Raises:

  • (ArgumentError) 


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# File 'lib/puppet/pops/merge_strategy.rb', line 27

def self.strategy(merge)
  TypeAsserter.assert_instance_of("MergeStrategies.merge 'merge' parameter", merge_t, merge)
  if merge.is_a?(Hash)
    merge_strategy = merge['strategy']
    if merge_strategy.nil?
      raise ArgumentError, "The hash given as 'merge' must contain the name of a strategy in string form for the key 'strategy'"
    end
    merge_options  = merge
  else
    merge_strategy = merge
    merge_options  = {}
  end
  strategy = strategies[merge_strategy.to_sym]
  raise ArgumentError, "Unknown merge strategy: '#{merge_strategy}'" if strategy.nil?
  strategy.new(merge_options)
end

.strategy_keys ⇒ Array<Symbol>

Returns the list of merge strategy keys known to this class

Returns:



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# File 'lib/puppet/pops/merge_strategy.rb', line 48

def self.strategy_keys
  strategies.keys
end

Instance Method Details

#convert_value(value) ⇒ Object

Converts a single value to the type expeced when peforming a merge of two elements

Parameters:

  • value (Object) —

    the value to convert

Returns:

  • (Object) —

    the converted value



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# File 'lib/puppet/pops/merge_strategy.rb', line 101

def convert_value(value)
  value
end

#merge(e1, e2) ⇒ Object

Merges the elements of e1 and e2 accoring to the implemented strategy and options given when this instance was created

Parameters:

  • e1 (Object) —

    The first element

  • e2 (Object) —

    The second element

Returns:

  • (Object) —

    The result of the merge



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# File 'lib/puppet/pops/merge_strategy.rb', line 92

def merge(e1, e2)
  checked_merge(
    assert_type('e1', value_t, e1),
    assert_type('e2', value_t, e2))
end