|  | // Copyright (c) 2015 The Chromium Authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style license that can be | 
|  | // found in the LICENSE file. | 
|  |  | 
|  | part of cassowary; | 
|  |  | 
|  | enum _SymbolType { invalid, external, slack, error, dummy, } | 
|  |  | 
|  | class _Symbol { | 
|  | final _SymbolType type; | 
|  | final int tick; | 
|  |  | 
|  | _Symbol(this.type, this.tick); | 
|  |  | 
|  | String toString() { | 
|  | String typeString = 'unknown'; | 
|  | switch (type) { | 
|  | case _SymbolType.invalid: | 
|  | typeString = 'i'; | 
|  | break; | 
|  | case _SymbolType.external: | 
|  | typeString = 'v'; | 
|  | break; | 
|  | case _SymbolType.slack: | 
|  | typeString = 's'; | 
|  | break; | 
|  | case _SymbolType.error: | 
|  | typeString = 'e'; | 
|  | break; | 
|  | case _SymbolType.dummy: | 
|  | typeString = 'd'; | 
|  | break; | 
|  | } | 
|  | return '$typeString$tick'; | 
|  | } | 
|  | } |