From 0d96a284e80fc3d79af9d56bacb05456b9ed3da4 Mon Sep 17 00:00:00 2001
From: Nuno Leiria <nuno@nunoleiria.com>
Date: Sat, 20 Mar 2021 23:28:02 +0000
Subject: [PATCH] std: Add reset to TokenIterator

---
 lib/std/mem.zig | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/std/mem.zig b/lib/std/mem.zig
index 2bd5fdac7b..66505f5d29 100644
--- a/lib/std/mem.zig
+++ b/lib/std/mem.zig
@@ -1373,6 +1373,20 @@ test "mem.tokenize (multibyte)" {
     testing.expect(it.next() == null);
 }
 
+test "mem.tokenize (reset)" {
+    var it = tokenize("   abc def   ghi  ", " ");
+    testing.expect(eql(u8, it.next().?, "abc"));
+    testing.expect(eql(u8, it.next().?, "def"));
+    testing.expect(eql(u8, it.next().?, "ghi"));
+
+    it.reset();
+
+    testing.expect(eql(u8, it.next().?, "abc"));
+    testing.expect(eql(u8, it.next().?, "def"));
+    testing.expect(eql(u8, it.next().?, "ghi"));
+    testing.expect(it.next() == null);
+}
+
 /// Returns an iterator that iterates over the slices of `buffer` that
 /// are separated by bytes in `delimiter`.
 /// split("abc|def||ghi", "|")
@@ -1471,6 +1485,11 @@ pub const TokenIterator = struct {
         return self.buffer[index..];
     }
 
+    /// Resets the iterator to the initial token.
+    pub fn reset(self: *TokenIterator) void {
+        self.index = 0;
+    }
+
     fn isSplitByte(self: TokenIterator, byte: u8) bool {
         for (self.delimiter_bytes) |delimiter_byte| {
             if (byte == delimiter_byte) {