Server, and it supports the extension of new databases with plugins. Ho How it w w it works orks St Step 0 (Pr ep 0 (Pre-kno e-knowledge) wledge) 1. Casdoor follows the authorization process built upon have a brief understanding of how OAuth 2.0 works. You can refer to this introduction to OAuth 2.0. St Step 1 (Aut ep 1 (Authorization R horization Request) equest) Your Application (which could be a website Application will make the user launch a request to this URL, and the Authorization Request is completed. St Step 2 (Aut ep 2 (Authorization Grant) horization Grant) This step is straightforward: the user is

s 有 有 有社 社 社区 区 区准 准 准则 则 则不 不 不？ ？ ？ 68 C H AP T E R 3 用 I d r i s 实现带有状态的系统：ST 教程 本教程叙述了如何用 奉 奤 奲 奩 女 的 Control.ST 库实现带有状态的系统。 注 注 注解 解 解: 奉 奤 奲 奩 女 文档已按照 创 创 创作 作 作共 共 共用 用 用 C C 0 许 许 许可 可 可协 协 本教程将介绍Control.ST 库，它支持对带有状态和副作用的程序进行编程和推理。 该库已包含在 奉 奤 奲 奩 女 发行版当中（目前属于 contrib 包）。本教程假设读者已经熟悉 I d r i s 教程 夨 姩 妡妵 夲天 中所述的纯函数式 的编程方法。ST 库基于《奉 奤 奲 奩 女 类型驱动开发》一书中第 失夳 和 失头 章所讨论的内容，如需更多背景信息 可以参考此书。 我们可使用 ST 库编写由多 前是否成功登录”这一性质非常重要。 ST 库能让我们在类型系统 中表达这类协 协 协议 议 议，并且在编 编 编译 译 译阶 阶 阶段 段 段确保机密数据只有在用户处于已登录状态时才能被读取。 3. 1. 2 大 大 大纲 纲 纲 本教程从描述如何操作独立的状态开始（S T 介绍：用状态来工作 夨 姩 妡妵 夷夰天 ），引入了 STrans 数据类 型来描述带有状态的函数，以及 ST 用来描述顶层的状态转移。

d at e d m or e of t e n . 66 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 66 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 67 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 66 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 72 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 66 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 71 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f

d at e d m or e of t e n . 70 C H AP T E R 3 I m p l e m e n t i n g St a t e - a w a r e Sy s t e m s i n I d r i s : T h e ST T u t o r i a l A t u t or i al on i m p l e m e n t i n g s t at e - t h e P I N v e r i fi e d . I n t h i s t u t or i al w e w i l l i n t r od u c e t h e Control.ST l i b r ar y , w h i c h i s i n c l u d e d w i t h t h e I d r i s d i s t r i b u t i on ( c u r d r i s T u t o r i a l ( p age 2) . F or f u r t h e r b ac k gr ou n d i n f or m at i on , t h e ST l i b r ar y i s b as e d on i d e as d i s c u s s e d i n C h ap t e r 13 ( av ai l ab l e as a f