Enum compression

compress.js

/**
 * Compress scopes with an emum into an efficient integer
 */
function compressScope(scopes, scopesEnum) {
  var value = scopesEnum.map(function(scope) {
    return (!!~scopes.indexOf(scope)) ? '1' : '0';
  }).join('');

  return parseInt(value, 2);
};

var requestedScopes = ['user:email', 'app:products']
  , scopesEnum = ['user:name', 'user:email', 'user:address', 'app:products', 'app:products:edit'];

compressScope(requestedScopes, scopesEnum) === 10; // 01010b