From 7411f5f9b86a3ab7422bc2e378553ba186f30119 Mon Sep 17 00:00:00 2001
From: jaina heartles <me@heartles.xyz>
Date: Thu, 2 Jun 2022 11:33:16 -0700
Subject: [PATCH] Add PathIter

---
 src/util/PathIter.zig | 68 +++++++++++++++++++++++++++++++++++++++++++
 src/util/lib.zig      |  2 ++
 2 files changed, 70 insertions(+)
 create mode 100644 src/util/PathIter.zig

diff --git a/src/util/PathIter.zig b/src/util/PathIter.zig
new file mode 100644
index 0000000..802300f
--- /dev/null
+++ b/src/util/PathIter.zig
@@ -0,0 +1,68 @@
+const Self = @This();
+
+const std = @import("std");
+
+is_first: bool,
+path: []const u8,
+
+pub fn from(path: []const u8) Self {
+    return .{ .path = path, .is_first = true };
+}
+
+pub fn next(self: *Self) ?[]const u8 {
+    if (self.path.len == 0) {
+        if (self.is_first) {
+            self.is_first = false;
+            return self.path;
+        } else {
+            return null;
+        }
+    }
+
+    var start: usize = 0;
+    var end: usize = start;
+    while (end < self.path.len) : (end += 1) {
+        // skip leading slash
+        if (end == start and self.path[start] == '/') {
+            start += 1;
+            continue;
+        } else if (self.path[end] == '/') {
+            break;
+        }
+    }
+
+    if (start == end) {
+        self.path = self.path[end..end];
+        self.is_first = false;
+        return null;
+    }
+
+    const result = self.path[start..end];
+    self.path = self.path[end..];
+    self.is_first = false;
+    return result;
+}
+
+test "PathIter /ab/cd/" {
+    const path = "/ab/cd/";
+    var it = from(path);
+    try std.testing.expectEqualStrings("ab", it.next().?);
+    try std.testing.expectEqualStrings("cd", it.next().?);
+    try std.testing.expectEqual(@as(?[]const u8, null), it.next());
+}
+
+test "PathIter ''" {
+    const path = "";
+    var it = from(path);
+    try std.testing.expectEqualStrings("", it.next().?);
+    try std.testing.expectEqual(@as(?[]const u8, null), it.next());
+}
+
+test "PathIter ab/c//defg/" {
+    const path = "ab/c//defg/";
+    var it = from(path);
+    try std.testing.expectEqualStrings("ab", it.next().?);
+    try std.testing.expectEqualStrings("c", it.next().?);
+    try std.testing.expectEqualStrings("defg", it.next().?);
+    try std.testing.expectEqual(@as(?[]const u8, null), it.next());
+}
diff --git a/src/util/lib.zig b/src/util/lib.zig
index 4a7e3df..a6a98b5 100644
--- a/src/util/lib.zig
+++ b/src/util/lib.zig
@@ -1,7 +1,9 @@
 pub const ciutf8 = @import("./ciutf8.zig");
 pub const Uuid = @import("./Uuid.zig");
+pub const PathIter = @import("./PathIter.zig");
 
 test {
     _ = ciutf8;
     _ = Uuid;
+    _ = PathIter;
 }