Class Text::Format::Roman
In: lib/text/format/roman.rb
Parent: Object

Provides a numbering object that will produce numbers. Accepts three parameters for numbering that will control how the numbers are presented when given as #[](index).

:offset:The number to add to the index in order to produce the proper index. This is because tag_text indexes from 0, not 1. This defaults to 1. Any value less than 1 will be set to 1 (because Romans did not know about zero or negative numbers).
:lower:Renders the Roman numerals in lowercase if true. Defaults to false.
:postfix:The value that will be appended to the number presented by #[]. Defaults to nil.
:prefix:The value that will be prepended to the number presented by #[]. Defaults to nil.
  r1 = Text::Format::Roman.new(:postfix => ".")
  puts r1[0]  # => "I."
  puts r1[8]  # => "IX.

  r2 = Text::Format::Roman.new(:prefix => "M.")
  puts r2[0]  # => "M.I"
  puts r2[8]  # => "M.IX"

  r3 = Text::Format::Roman.new(:offset => 3)
  puts r3[0]  # => "III"
  puts r3[9]  # => "XII"

  r4 = Text::Format::Roman.new(:offset => 0)
  puts r4[0]  # => "I"
  puts r4[8]  # => "IX"

  r5 = Text::Format::Roman.new(:lower => true)
  puts r5[0]  # => "i"
  puts r5[8]  # => "ix"

Methods

[]   new  

Public Class methods

[Source]

# File lib/text/format/roman.rb, line 97
  def initialize(options = {})
    @offset   = options[:offset].to_i || 1
    @lower    = options[:lower]       || false
    @postfix  = options[:postfix]     || nil
    @prefix   = options[:prefix]      || nil

    @offset   = 1 if @offset < 1
  end

Public Instance methods

[Source]

# File lib/text/format/roman.rb, line 37
  def [](index)
    roman = ""
    index += @offset

      # Do 1,000s
    roman << "M" * (index / 1000)
    index %= 1000

      # Do 900s
    roman << "CM" * (index / 900)
    index %= 900

      # Do 500s
    roman << "D" * (index / 500)
    index %= 500

      # Do 400s
    roman << "CD" * (index / 400)
    index %= 400

      # Do 100s
    roman << "C" * (index / 100)
    index %= 100

      # Do 90s
    roman << "XC" * (index / 90)
    index %= 90

      # Do 50s
    roman << "L" * (index / 50)
    index %= 50

      # Do 40s
    roman << "XL" * (index / 40)
    index %= 40

      # Do 10s
    roman << "X" * (index / 10)
    index %= 10

      # Do 9s
    roman << "IX" * (index / 9)
    index %= 9

      # Do 5s
    roman << "V" * (index / 5)
    index %= 5

      # Do 4s
    roman << "IV" * (index / 4)
    index %= 4

      # Do 1s
    roman << "I" * index

    roman.downcase! if @lower

    "#{@prefix}#{roman}#{@postfix}"
  end

[Validate]