From 0cc3d8e258e2cad61b9106a156ee07d560be7b3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=96=87=E5=AE=87=E7=A5=A5?= <hackwaly@qq.com>
Date: Tue, 4 Jun 2024 20:13:37 +0800
Subject: [PATCH] Add RegExp.setLastIndex (#219)

---
 CHANGELOG.md          |  1 +
 src/Core__RegExp.res  |  1 +
 src/Core__RegExp.resi | 20 ++++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cee1d93..878eeff8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Next version
 
+- Add `RegExp.setLastIndex` function. https://github.com/rescript-association/rescript-core/pull/219
 - Add `Nullable.isNullable` function. https://github.com/rescript-association/rescript-core/pull/227
 - Remove some deps to Belt, Pervasives and Js. https://github.com/rescript-association/rescript-core/pull/226/commits
 
diff --git a/src/Core__RegExp.res b/src/Core__RegExp.res
index 84668ae0..441b328a 100644
--- a/src/Core__RegExp.res
+++ b/src/Core__RegExp.res
@@ -15,6 +15,7 @@ module Result = {
 @return(nullable) @send external exec: (t, string) => option<Result.t> = "exec"
 
 @get external lastIndex: t => int = "lastIndex"
+@set external setLastIndex: (t, int) => unit = "lastIndex"
 @get external ignoreCase: t => bool = "ignoreCase"
 @get external global: t => bool = "global"
 @get external multiline: t => bool = "multiline"
diff --git a/src/Core__RegExp.resi b/src/Core__RegExp.resi
index e16ba1e9..4e42be94 100644
--- a/src/Core__RegExp.resi
+++ b/src/Core__RegExp.resi
@@ -170,6 +170,26 @@ Console.log(regexp->RegExp.lastIndex) // Logs `4` to the console
 @get
 external lastIndex: t => int = "lastIndex"
 
+/**
+`setLastIndex(regexp, index)` set the index the next match will start from.
+
+See [`RegExp.lastIndex`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/lastIndex) on MDN.
+
+## Examples
+```rescript
+// Match the first word in a sentence
+let regexp = RegExp.fromString("\\w+")
+let someStr = "Many words here."
+
+regexp->RegExp.setLastIndex(4)
+regexp->RegExp.exec(someStr)->ignore
+
+Console.log(regexp->RegExp.lastIndex) // Logs `10` to the console
+```
+*/
+@set
+external setLastIndex: (t, int) => unit = "lastIndex"
+
 /**
 `ignoreCase(regexp)` returns whether the ignore case (`i`) flag is set on this `RegExp`.