Class: Factree::Facts

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/factree/facts.rb

Constant Summary collapse

MISSING_FACTS =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

Kernel#catch uses object ID to match thrown values. This gives us a unique ID and a readable message in case it’s thrown somewhere it’s not expected.

"Attempted to read missing facts from a Factree::Facts instance"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(**hash) ⇒ Facts

Returns a new instance of Facts.



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# File 'lib/factree/facts.rb', line 15

def initialize(**hash)
  @hash = hash.freeze
  freeze
end

Class Method Details

.catch_missing_facts ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/factree/facts.rb', line 60

def self.catch_missing_facts
  catch(MISSING_FACTS) do
    yield
  end
end

.coerce(source) ⇒ Object 



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# File 'lib/factree/facts.rb', line 10

def self.coerce(source)
  return source if source.is_a? self
  new(**source)
end

.throw_missing_facts ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/factree/facts.rb', line 55

def self.throw_missing_facts
  throw MISSING_FACTS
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/factree/facts.rb', line 50

def ==(other)
  self.to_h == other.to_h
end

#[](fact_name) ⇒ Object

Gets the value of a fact. This also #requires the fact.

Parameters:

  • fact_name (Symbol)

Returns:

  • (Object) 


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# File 'lib/factree/facts.rb', line 40

def [](fact_name)
  self.require fact_name
  peek fact_name
end

#known?(fact_name) ⇒ Boolean

Checks to see if a fact is present.

Parameters:

  • fact_name (Symbol)

Returns:

  • (Boolean) 


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# File 'lib/factree/facts.rb', line 24

def known?(fact_name)
  @hash.has_key? fact_name
end

#peek(fact_name) ⇒ Object

Gets the value of a fact, if present, without #requireing the fact.



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# File 'lib/factree/facts.rb', line 46

def peek(fact_name)
  @hash[fact_name]
end

#require(*fact_names) ⇒ void

This method returns an undefined value.

Requires that certain facts are present in order to proceed with the decision. If any of the facts are missing, the path will stop here.

Parameters:

  • fact_names (Array<Symbol>) —

    Names of facts to require



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# File 'lib/factree/facts.rb', line 32

def require(*fact_names)
  self.class.throw_missing_facts unless fact_names.all? { |name| known? name }
end