gistfile1.txt

+angular.module( 'gizmos.filters' ).filter( 'indexToAlphabet', [
 +  function() {
 +    return function( index, lettercase ) {
 +      var index, alphabet, len
 +
 +      alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 +      len = ( alphabet.length - 1 )
 +
 +      if ( lettercase === 'lowercase' ) {
 +        alphabet = alphabet.toLowerCase()
 +      }
 +
 +      alphabet = alphabet.split("")
 +      index = Math.abs( +index ) || 0
 +
 +      if ( index > len ) {
 +        return alphabet[ 0 ]
 +      }
 +
 +      return alphabet[ index ]
 +
 +    }
 +  }
 +]);