From 7fbb3631761518614a2f90c047ccf57b1579efd9 Mon Sep 17 00:00:00 2001
From: Sanchime <sanchime.qq.com>
Date: Sat, 14 May 2022 20:31:13 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0Linq?=
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---
 Sanchime.Functional/Monads/FreeMonad.cs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Sanchime.Functional/Monads/FreeMonad.cs b/Sanchime.Functional/Monads/FreeMonad.cs
index 6721cd0..0e10705 100644
--- a/Sanchime.Functional/Monads/FreeMonad.cs
+++ b/Sanchime.Functional/Monads/FreeMonad.cs
@@ -72,4 +72,17 @@ public static class FreeMonad
 
     internal static Free<T> More<T>(Coyo<object, Free<T>> value) 
         => new More<T>(value);
+
+    #region Linq
+
+    public static Free<R> Select<T, R>(this Free<T> @this, Func<T, R> mapping)
+        => @this.Match(val => Done<R>(mapping(val)), op => More(op.Map(free => free.Select(mapping))));
+
+    public static Free<R> SelectMany<T, R>(this Free<T> @this, Func<T, Free<R>> binding)
+        => @this.Match(binding, op => More(op.Map(free => free.SelectMany(binding))));
+
+    public static Free<RR> SelectMany<T, R, RR>(this Free<T> @this, Func<T, Free<R>> binding, Func<T, R, RR> project)
+        => @this.SelectMany(val => Select(binding(val), res => project(val, res)));
+
+    #endregion
 }