Class: FactChecker::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/fact_checker/base.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(facts = nil, deps = nil, reqs = nil) ⇒ Base

Returns a new instance of Base.



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# File 'lib/fact_checker/base.rb', line 7

def initialize(facts = nil, deps = nil, reqs = nil)
  @facts        = facts || []
  @dependencies = deps  || {}
  @requirements = reqs  || {}
end

Instance Attribute Details

#dependencies ⇒ Object

Returns the value of attribute dependencies.



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# File 'lib/fact_checker/base.rb', line 5

def dependencies
  @dependencies
end

#facts ⇒ Object

Returns the value of attribute facts.



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# File 'lib/fact_checker/base.rb', line 5

def facts
  @facts
end

#requirements ⇒ Object

Returns the value of attribute requirements.



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# File 'lib/fact_checker/base.rb', line 5

def requirements
  @requirements
end

Instance Method Details

#accomplished_facts(context) ⇒ Object 



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# File 'lib/fact_checker/base.rb', line 20

def accomplished_facts(context)
  facts.select{ |fact| fact_accomplished?(context, fact) }
end

#def_fact(*opt) ⇒ Object

Syntactic sugar, adds fact with its requirement and dependency. Examples:

  • def_fact(:fact)

  • def_fact(:fact, :if => :requirement)

  • def_fact(:fact => :dependency)

  • def_fact(:fact => :dependency, :if => :requirement)

Raises:

  • (ArgumentError) 


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# File 'lib/fact_checker/base.rb', line 55

def def_fact(*opt)
  raise ArgumentError, "wrong number of arguments (#{opt.size} for 2)" if opt.size > 2
  raise ArgumentError, "wrong number of arguments (0 for 1)"           if opt.size == 0

  if opt[0].is_a?(Hash)
    raise ArgumentError, "wrong arguments (hash argument can only be the last one)" if opt.size > 1
    hash = opt[0]
  else
    raise ArgumentError, "wrong arguments (second argument must be a hash)" if opt[1] && ! opt[1].is_a?(Hash)
    hash = (opt[1] || {}).merge(opt[0] => nil)
  end

  req  = hash.delete(:if)
  fact = hash.keys.first
  dep  = hash.delete(fact)

  raise ArgumentError, "wrong arguments: #{hash.keys.join(', ')}" if hash.size > 0

  @requirements[fact] = req
  @dependencies[fact] = dep
  @facts |= [fact]
  fact
end

#fact_accomplished?(context, fact) ⇒ Boolean

Checks if requirement and dependency for the fact are satisfied

Returns:

  • (Boolean) 


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# File 'lib/fact_checker/base.rb', line 29

def fact_accomplished?(context, fact)
  fact_possible?(context, fact) && requirement_satisfied_for?(context, fact)
end

#fact_possible?(context, fact) ⇒ Boolean

Checks if dependency for the fact is satisfied

Returns:

  • (Boolean) 


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# File 'lib/fact_checker/base.rb', line 34

def fact_possible?(context, fact)
  [* @dependencies[fact] || []].all?{ |dep| fact_accomplished?(context, dep) }
end

#initialize_copy(orig) ⇒ Object 



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# File 'lib/fact_checker/base.rb', line 13

def initialize_copy(orig)
  super
  @facts = orig.facts.dup
  @dependencies = orig.dependencies.dup
  @requirements = orig.requirements.dup
end

#possible_facts(context) ⇒ Object 



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# File 'lib/fact_checker/base.rb', line 24

def possible_facts(context)
  facts.select{ |fact| fact_possible?(context, fact) }
end

#requirement_satisfied_for?(context, fact) ⇒ Boolean

Checks if requirement for the fact is satisfied (no dependency checks here)

Returns:

  • (Boolean) 


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# File 'lib/fact_checker/base.rb', line 39

def requirement_satisfied_for?(context, fact)
  return false unless @facts.include?(fact)

  case req = @requirements[fact]
  when Symbol   then context.send(req)
  when Proc     then req.arity < 1 ? req.call : req.call(context)
  when NilClass then true
  else raise RuntimeError, "can't check this fact - wrong requirement"
  end
end