Class: Factbase::Env

Inherits:
TermBase
  • Object
show all
Defined in:
lib/factbase/terms/env.rb

Overview

The Factbase::Env class is used to evaluate terms based on environment variables. It retrieves the value of an environment variable or returns a default value if the variable is not set.

Instance Method Summary collapse

Constructor Details

#initialize(operands) ⇒ Env

Constructor.

Parameters:

  • operands (Array) —

    Operands



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# File 'lib/factbase/terms/env.rb', line 13

def initialize(operands)
  super()
  @operands = operands
end

Instance Method Details

#evaluate(fact, maps, fb) ⇒ String

Evaluate term on a fact.

Parameters:

Returns:

  • (String) —

    The value of the environment variable or the default



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# File 'lib/factbase/terms/env.rb', line 23

def evaluate(fact, maps, fb)
  assert_args(2)
  n = _values(0, fact, maps, fb)
  return if n.nil?
  ENV.fetch(n[0].upcase) do
    d = _values(1, fact, maps, fb)
    return if d.nil?
    d[0]
  end
end