Class: GhostWheel::Expression::Optional

Inherits:
GhostWheel::Expression show all
Defined in:
lib/ghost_wheel/expression/optional.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from GhostWheel::Expression

#parse

Constructor Details

#initialize(expression) ⇒ Optional

Returns a new instance of Optional.



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# File 'lib/ghost_wheel/expression/optional.rb', line 6

def initialize(expression)
  @expression = expression
end

Instance Attribute Details

#expression ⇒ Object (readonly)

Returns the value of attribute expression.



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# File 'lib/ghost_wheel/expression/optional.rb', line 10

def expression
  @expression
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/ghost_wheel/expression/optional.rb', line 21

def ==(other)
  super and @expression == other.expression
end

#uncached_parse(scanner, cache) ⇒ Object 



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# File 'lib/ghost_wheel/expression/optional.rb', line 12

def uncached_parse(scanner, cache)
  result = @expression.parse(scanner, cache)
  if result.is_a? FailedParseResult
    EmptyParseResult.instance
  else
    result
  end
end