add iterator

Author: ziteh

iterator/basic.zig

@@ -0,0 +1,15 @@
+const std = @import("std");
+const print = std.debug.print;
+
+pub fn main() void {
+    const string = "C,C++,Python,TypeScript";
+    var iter = std.mem.split(u8, string, ",");
+
+    while (true) {
+        const item = iter.next();
+        if (item == null) {
+            break;
+        }
+        print("{s}\n", .{item.?});
+    }
+}

iterator/custom.zig

@@ -0,0 +1,34 @@
+const std = @import("std");
+const print = std.debug.print;
+
+const MyIterator = struct {
+    list: []const i32,
+    exclude: i32,
+    index: usize = 0,
+
+    fn next(self: *MyIterator) ?i32 {
+        for (self.list[self.index..]) |item| {
+            self.index += 1;
+            if (item == self.exclude) {
+                continue;
+            }
+            return item;
+        }
+        return null;
+    }
+};
+
+pub fn main() void {
+    var iter = MyIterator{
+        .list = &[_]i32{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 },
+        .exclude = 5,
+    };
+
+    while (true) {
+        const item = iter.next();
+        if (item == null) {
+            break;
+        }
+        print("{}\n", .{item.?});
+    }
+}

iterator/readme.md

@@ -0,0 +1,22 @@
+# Iterators
+
+```bash
+$ zig run basic.zig
+C
+C++
+Python
+TypeScript
+```
+
+```bash
+$ zig run custom.zig
+1
+2
+3
+4
+6
+7
+8
+9
+10
+```