Parse access flags

src/EnumFlags.zig

@@ -0,0 +1,44 @@
+const std = @import("std");
+
+pub fn EnumFlags(comptime E: type) type {
+    return packed struct {
+        const Self = @This();
+
+        const BackingInt = @typeInfo(E).@"enum".tag_type;
+
+        mask: BackingInt,
+
+        pub const empty: Self = .{ .data = 0 };
+
+        pub fn contains(self: Self, flag: E) bool {
+            return (self.mask & @intFromEnum(flag)) != 0;
+        }
+
+        pub fn insert(self: *Self, flag: E) void {
+            self.mask |= @intFromEnum(flag);
+        }
+
+        pub fn remove(self: *Self, flag: E) void {
+            self.mask &= ~@intFromEnum(flag);
+        }
+
+        pub fn toggle(self: *Self, flag: E) void {
+            self.mask ^= @intFromEnum(flag);
+        }
+
+        pub fn format(self: *const Self, w: *std.Io.Writer) std.Io.Writer.Error!void {
+            var index: usize = 0;
+            inline for (std.meta.fields(E)) |field| {
+                const key = @field(E, field.name);
+                if (self.contains(key)) {
+                    if (index > 0) {
+                        _ = try w.write(" | ");
+                    }
+                    try w.print("{s}", .{ field.name });
+                    index += 1;
+                }
+            }
+        }
+    };
+}
+