greekish.js

function toGreeklish(text) {

/*@cc_on @if (@_jscript_version <= 5.0) return 'Scripting engine ' + @_jscript_version + ' not supported' @end @*/

var grCaps = stringToSet('ΑΆΒΓΔΕΈΖΗΉΘΙΊΪΚΛΜΝΞΟΌΠΡΣΤΥΎΫΦΧΨΩΏ')

var replacements = [

  {greek:'αι', greeklish:'ai'},

  {greek:'αί', greeklish:'ai'},

  {greek:'οι', greeklish:'oi'},

  {greek:'οί', greeklish:'oi'},

  {greek:'ου', greeklish:'ou'},

  {greek:'ού', greeklish:'ou'},

  {greek:'ει', greeklish:'ei'},

  {greek:'εί', greeklish:'ei'},

  {greek:'αυ', fivi:1},

  {greek:'αύ', fivi:1},

  {greek:'ευ', fivi:1},

  {greek:'εύ', fivi:1},

  {greek:'ηυ', fivi:1},

  {greek:'ηύ', fivi:1},

  {greek:'ντ', greeklish:'nt'},

  {greek:'μπ', bi:1},

  {greek:'τσ', greeklish:'ts'},

  {greek:'τζ', greeklish:'tz'},

  {greek:'γγ', greeklish:'ng'},

  {greek:'γκ', greeklish:'gk'},

  {greek:'γχ', greeklish:'nch'},

  {greek:'γξ', greeklish:'nx'},

  {greek:'θ' , greeklish:'th'},

  {greek:'χ' , greeklish:'ch'},

  {greek:'ψ' , greeklish:'ps'},

]

// Remove extraneus array element

if (!replacements[replacements.length - 1]) replacements.pop()

// Enchance replacements

for (var i = 0, replacement; replacement = replacements[i]; i++) {

  replacements[replacement.greek] = replacement

}

// Append single letter replacements

var grLetters  = 'αάβγδεέζηήθιίϊΐκλμνξοόπρσςτυύϋΰφχψωώ'

var engLetters = 'aavgdeezii.iiiiklmnxooprsstyyyyf..oo'

for (var i = 0; i < grLetters.length; i++) {

  if (!replacements[grLetters.charAt(i)]) {

    replacements.push({greek:grLetters.charAt(i), greeklish:engLetters.charAt(i)})

  }

}

// Enchance replacements, build expression

var expression = []

for (var i = 0, replacement; replacement = replacements[i]; i++) {

  replacements[replacement.greek] = replacement

  expression[i] = replacement.greek

}

expression = new RegExp(expression.join('|'), 'gi')

// Replace greek with greeklsh

var greekSet = stringToSet(grLetters)

var viSet = stringToSet('αβγδεζηλιmμνορω')

text = text.replace(expression, function($0, index) {

  var replacement = replacements[$0.toLowerCase()]

  if (replacement.bi) {

    var bi = (greekSet[text.charAt(index - 1).toLowerCase()] && greekSet[text.charAt(index + 2).toLowerCase()]) ? 'mp' : 'b'

    return fixCase(bi, $0)

  } else if (replacement.fivi) {

    var c1 = replacements[$0.charAt(0).toLowerCase()].greeklish

    var c2 = viSet[text.charAt(index + 2).toLowerCase()] ? 'v' : 'f'

    return fixCase(c1 + c2, $0)

  } else {

    return fixCase(replacement.greeklish, $0 + text.charAt(index + $0.length))

  }

})

    return text

    function fixCase(text, mirror) {

      if (grCaps[mirror.charAt(0)]) {

        if (mirror.length == 1 || grCaps[mirror.charAt(1)]) {

          return text.toUpperCase()

        } else {

          return text.charAt(0).toUpperCase() + text.substr(1)

        }

      } else {

        return text

      }

    }

    function stringToSet(s) {

      var o = {}

      for (var i = 0; i < s.length; i++) {

        o[s.charAt(i)] = 1

      }

      return o

    }
}