Module: RPN

Defined in:
lib/rpn_ruby.rb,
lib/rpn_ruby/version.rb

Constant Summary collapse

VERSION = 
"0.0.1"

Instance Method Summary collapse

Instance Method Details

#enter(value) ⇒ Object 



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# File 'lib/rpn_ruby.rb', line 13

def enter value
  case value
    when '='
     return result
    when '+'
     @stack.push @stack.pop + @stack.pop
    when '-'
     subtrahend = @stack.pop
     @stack.push @stack.pop - subtrahend
    when '*'
     @stack.push @stack.pop * @stack.pop
    when '^'
     exponent = @stack.pop
     @stack.push @stack.pop ** exponent
    when 'r'
     rt = @stack.pop
     @stack.push @stack.pop.root rt
    when '/', 'd'
     divisor = @stack.pop
     @stack.push @stack.pop / divisor
    when '%'
     divisor = @stack.pop
     @stack.push @stack.pop % divisor
    else 
      @stack.push value.to_f
  end    
  self
rescue Exception => @err
  @stack.push 'invalid input'
  return self
end

#initialize ⇒ Object 



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# File 'lib/rpn_ruby.rb', line 9

def initialize
  @stack = []
end

#result ⇒ Object 



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# File 'lib/rpn_ruby.rb', line 45

def result
  @stack.first.to_s || ''
end