gistfile1.rb

Tones = {
  1 => :flat,
  2 => :up,
  3 => :downup,
  4 => :down,
  5 => :notone,
}

# where v = umlaut
Vowels = [
  'a',
  'ai',
  'an',
  'ao',
  'ang',

  'o',
  'ou',
  'ong',

  'e',
  'ei',
  'en',
  'er',
  'eng',

  'i',
  'ia',
  'ie',
  'iao',
  'iou', 'iu',  # synonyms
  'ian',
  'in',
  'iang',
  'ing',
  'iong',

  'u',
  'ua',
  'uo',
  'uai',
  'uei', 'ui',  # synonyms
  'uan',
  'uen', 'un',  # synonyms
  'uang',
  'ueng',

  'v',
  've',
  'van',
  'vn',
]

Consonants = [
  'b',
  'p',
  'm',
  'f',
  'd',
  't',
  'n',
  'l',
  'g',
  'k',
  'h',
  'j',
  'q',
  'x',
  'zh',
  'ch',
  'sh',
  'r',
  'z',
  'c',
  's'
]

Converters = [
  ['ie([1-5])', 'ie$1'],
  ['ia([1-5])', 'ia$1'],
  ['iu([1-5])', 'iu$1'],
  
  ['([aeiouv])n([1-5])', '$1$2n'],
  ['([aeiouv])ng([1-5])', '$1$2ng'],

  ['([aeiouv][aeiouv])([aeiouv])([1-5])', '$1$3$2'],
  ['([aeiouv])([aeiouv])([1-5])', '$1$3$2'],
  ['([aeiouv][1-5])', '$1'],
  ['([aeiouv])' , '$1']
]

Unicode_characters = {
  'a1' => '',
  'a2' => '',
  'a3' => '',
  'a4' => '',

  'e1' => '',
  'e2' => '',
  'e3' => '',
  'e4' => '',

  'i1' => '',
  'i2' => '',
  'i3' => '',
  'i4' => '',

  'o1' => '',
  'o2' => '',
  'o3' => '',
  'o4' => '',
  'o5' => '',

  'u1' => '',
  'u2' => '',
  'u3' => '',
  'u4' => '',
  'u5' => '',

  'v' => '',
  'v1' => '',
  'v2' => '',
  'v3' => '',
  'v4' => '',
}

def partial_convert(from)
  s = from.split("+").each do |str|
    Converters.each do |c|
      str.gsub!("#{c[0][^+]", "#c[1]+")  # find all the patterns and mark them as dealt with by appending '+'
      str.replace!("+","")               # remove all the + we added in.
    end
  end
  s.join("+")  # add back in the + included in the original string
end

def to_unicode(from)
  s = partial_convert from
  Unicode_characters.each do |syntax, code|
    s.gsub! syntax, code
  end
  s
end

puts to_unicode 'mei2 guan1xi'