Add Path.equals

src/path.zig

@@ -256,6 +256,21 @@ pub const Path = struct {
         try self.write(opt, writer);
     }
 
+    /// Returns whether the contents of the specified `Path`s are equivalent.
+    ///
+    /// Path equivalency does not imply these paths are or are not referring to
+    /// the same `Entity`. For example, an entity that is referred to using its
+    /// entity id has a different path from the same entity referred to by name.
+    pub fn equals(first: Path, second: Path) bool {
+        if (first.absolute != second.absolute) return false;
+        if (first.parts.len != second.parts.len) return false;
+        for (first.parts, second.parts) |a, b| switch (a) {
+            .name => |a_name| if (b != .name or !std.mem.eql(u8, a_name, b.name)) return false,
+            .id => |a_id| if (b != .id or a_id != b.id) return false,
+        };
+        return true;
+    }
+
     fn calculateLength(self: Path, opt: FormatOptions) usize {
         // Separators.
         var result = opt.sep.len * (self.parts.len - 1);
@@ -329,6 +344,7 @@ pub const Path = struct {
 
 test Path {
     const alloc = std.testing.allocator;
+    const expect = std.testing.expect;
     const expectFmt = std.testing.expectFmt;
     const expectEqual = std.testing.expectEqual;
     const expectEqualStrings = std.testing.expectEqualStrings;
@@ -386,9 +402,7 @@ test Path {
     // Numeric ids can also be passed to `buildParts`.
     const numeric2_parts = Path.buildParts(.{ 100, 101, "bar" });
     const numeric2 = try Path.fromParts(false, &numeric2_parts);
-
-    // TODO: Let's check numeric1 and numeric2 for equality here.
-    _ = numeric2;
+    try expect(numeric1.equals(numeric2));
 
     // Paths are formattable. As format specifier you can use options defined
     // on the `FormatOptions` type, or an empty string to use the default.