code: function registerExport(exports, decl) {
      function register(name, exp) {
          if (exports.has(name))
              throw new SyntaxError("multiple exports of " + name);
          exports.set(name, exp);
      }
  
      switch (decl.type) {
        case MODULE:
        case FUNCTION:
          register(decl.name, new Export(decl, true));
          break;
  
        case VAR:
          for (var i = 0; i < decl.children.length; i++)
              register(decl.children[i].name, new Export(decl.children[i], true));
          break;
  
        case LET:
        case CONST:
          throw new Error("NYI: " + definitions.tokens[decl.type]);
  
        case EXPORT:
          for (var i = 0; i < decl.pathList.length; i++) {
              var path = decl.pathList[i];
              switch (path.type) {
                case OBJECT_INIT:
                  for (var j = 0; j < path.children.length; j++) {
                      // init :: IDENTIFIER | PROPERTY_INIT
                      var init = path.children[j];
                      if (init.type === IDENTIFIER)
                          register(init.value, new Export(init, false));
                      else
                          register(init.children[0].value, new Export(init.children[1], false));
                  }
                  break;
  
                case DOT:
                  register(path.children[1].value, new Export(path, false));
                  break;
  
                case IDENTIFIER:
                  register(path.value, new Export(path, false));
                  break;
  
                default:
                  throw new Error("unexpected export path: " + definitions.tokens[path.type]);
              }
          }
          break;
  
        default:
          throw new Error("unexpected export decl: " + definitions.tokens[exp.type]);
      }
  }
docs: /*
  registerExport :: (Dict, EXPORT node) -> void