From 967e1e32661a53f896dcd07c832cdd5e205c6be3 Mon Sep 17 00:00:00 2001
From: Suzanne Soy <env@suzanne.soy>
Date: Wed, 19 Aug 2020 02:27:39 +0000
Subject: [PATCH] Simple function memoization
---
Utils/Func.cs | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/Utils/Func.cs b/Utils/Func.cs
index 5572467..19e942a 100644
--- a/Utils/Func.cs
+++ b/Utils/Func.cs
@@ -1,4 +1,5 @@
using System;
+using System.Collections.Generic;
using System.Linq;
public static class Func {
@@ -26,4 +27,17 @@ public static class Func {
public static Func<A,Func<B,Func<C,D>>> Curry<A,B,C,D>(this Func<A,B,C,D> f) {
return a => b => c => f(a, b, c);
}
+
+ public static Func<A, B> Memoize<A, B>(this Func<A, B> f) where A : IEquatable<A> {
+ var d = new Dictionary<A, B>();
+ return a => {
+ if (d.TryGetValue(a, out var b)) {
+ return b;
+ } else {
+ var calcB = f(a);
+ d.Add(a, calcB);
+ return calcB;
+ }
+ };
+ }
}
\ No newline at end of file