Question

我正在尝试在Coq中使用基于树的地图，特别是Coq.FSets.FMapAVL。

我发现了这个4岁的问题：Finite map example

查看评论中引用的标准lib文档，我看到了这个注释：

注意：此文件仅用于与早期版本的FSets和FMap兼容。请立即使用Structures / Orders.v。

这是什么意思？当我google＆＃34; Structures.v＆＃34;或＆＃34; Orders.v＆＃34;我总是在其他文档页面上找到相关的弃用警告。

在Coq 8.6中使用FMap的正确，不推荐的方法是什么？

Answer 1

由于OrderedTypeEx模块已弃用，我们不会使用其中定义的Nat_as_OT。

Nat_as_OT中有OrdersEx（只是PeanoNat.Nat的同义词），这对我们来说非常有用。

不幸的是，以下代码

Require Import Coq.Structures.OrdersEx.
Module M := FMapAVL.Make Nat_as_OT.

无法正常工作，因为签名OrderedType.OrderedType（目前由FMapAVL使用）和Orders.OrderedType不兼容。

但是，OrdersAlt模块包含仿函数，这些仿函数允许从另一个类型构建一个类型的模块。在这种情况下，我们对Backport_OT感兴趣。以下代码显示了如何使用FMapAVL.Make，其余代码可以从链接的问题中复制：

From Coq Require Import
FSets.FMapAVL Structures.OrdersEx Structures.OrdersAlt.

Module backNat_as_OT := Backport_OT Nat_as_OT.
Module M := FMapAVL.Make backNat_as_OT.

Pierre {4}}在this Coq-Club post解释了FMapAVL的情况：

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在Coq 8.6中使用FMap的正确方法？

1 个答案: