Module: LLT::Helpers::RomanNumerals

Defined in:
lib/llt/helpers/roman_numerals.rb

Class Method Summary collapse

Class Method Details

.roman?(value) ⇒ Boolean

Uncapitalized numerals will NOT be detected atm.

Returns:

  • (Boolean) 


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# File 'lib/llt/helpers/roman_numerals.rb', line 12

def roman?(value)
  /^[CDILMVX]*$/.match(value)
end

.to_decimal(value) ⇒ Object

IV to 4



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# File 'lib/llt/helpers/roman_numerals.rb', line 30

def to_decimal(value)
  res = 0
  numerals.each do |_, rom|
    while value.start_with?(rom)
      value = value[rom.length..-1]
      res += numerals.key(rom)
    end
  end

  res
end

.to_roman(value) ⇒ Object

4 to IV



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# File 'lib/llt/helpers/roman_numerals.rb', line 17

def to_roman(value)
  res = ""
  numerals.each do |dec, _|
    while value >= dec
      value -= dec
      res << numerals[dec]
    end
  end

  res
end