feat: integrate with some third-party library (#6)

Signed-off-by: tison <wander4096@gmail.com>

Author: tisonkun

Cargo.lock

@@ -26,6 +26,8 @@ rust-version.workspace = true
 [features]
 default = []
 derive = ["visitor-derive"]
+
+# Implement Traversal for standard library types.
 std = []
 
 # Visit all trivial types.
@@ -45,8 +47,16 @@ traverse-trivial = []
 # traversed via their contained types.
 traverse-std = []
 
+# Implement Traversal for third-party library types.
+ordered-float-5 = ["dep:ordered-float-5"]
+stacksafe-01 = ["dep:stacksafe-01"]
+
 [dependencies]
 visitor-derive = { workspace = true, optional = true }
 
+# Optional dependencies for third-party library support
+ordered-float-5 = { version = "5.1", default-features = false, optional = true, package = "ordered-float" }
+stacksafe-01 = { version = "0.1", default-features = false, optional = true, package = "stacksafe" }
+
 [lints]
 workspace = true

visitor/Cargo.toml

@@ -0,0 +1,18 @@
+// Copyright 2025 FastLabs Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[cfg(feature = "ordered-float-5")]
+mod ordered_float_5;
+#[cfg(feature = "stacksafe-01")]
+mod stacksafe_01;

visitor/src/function/mod.rs renamed to visitor/src/function.rs

@@ -0,0 +1,38 @@
+// Copyright 2025 FastLabs Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::ops::ControlFlow;
+
+use ordered_float_5::OrderedFloat;
+
+use crate::Traversable;
+use crate::TraversableMut;
+use crate::Visitor;
+use crate::VisitorMut;
+
+impl<T: 'static> Traversable for OrderedFloat<T> {
+    fn traverse<V: Visitor>(&self, visitor: &mut V) -> ControlFlow<V::Break> {
+        visitor.enter(self)?;
+        visitor.leave(self)?;
+        ControlFlow::Continue(())
+    }
+}
+
+impl<T: 'static> TraversableMut for OrderedFloat<T> {
+    fn traverse_mut<V: VisitorMut>(&mut self, visitor: &mut V) -> ControlFlow<V::Break> {
+        visitor.enter_mut(self)?;
+        visitor.leave_mut(self)?;
+        ControlFlow::Continue(())
+    }
+}

visitor/src/impls/mod.rs

@@ -0,0 +1,32 @@
+// Copyright 2025 FastLabs Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::ops::ControlFlow;
+
+use stacksafe_01::StackSafe;
+
+use crate::Traversable;
+use crate::TraversableMut;
+
+impl<T: Traversable> Traversable for StackSafe<T> {
+    fn traverse<V: crate::Visitor>(&self, visitor: &mut V) -> ControlFlow<V::Break> {
+        (**self).traverse(visitor)
+    }
+}
+
+impl<T: TraversableMut> TraversableMut for StackSafe<T> {
+    fn traverse_mut<V: crate::VisitorMut>(&mut self, visitor: &mut V) -> ControlFlow<V::Break> {
+        (**self).traverse_mut(visitor)
+    }
+}

visitor/src/impls/ordered_float_5.rs

@@ -32,6 +32,9 @@ pub use visitor_derive::TraversableMut;
 
 pub mod function;
 
+/// Implementations for third-party library types.
+mod impls;
+
 /// A visitor that can be used to traverse a data structure.
 pub trait Visitor {
     /// The type that can be used to break traversal early.

visitor/src/impls/stacksafe_01.rs

@@ -0,0 +1,83 @@
+// Copyright 2025 FastLabs Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg(all(feature = "derive", feature = "ordered-float-5"))]
+
+use std::any::Any;
+use std::ops::ControlFlow;
+
+use ordered_float_5::OrderedFloat;
+use visitor::Traversable as _;
+use visitor::TraversableMut as _;
+use visitor::Visitor;
+use visitor::VisitorMut;
+use visitor_derive::Traversable;
+use visitor_derive::TraversableMut;
+
+#[test]
+fn test_ordered_float() {
+    #[derive(Debug, Clone, PartialEq, Eq, Traversable, TraversableMut)]
+    pub enum Literal {
+        Null,
+        Float(OrderedFloat<f64>),
+    }
+
+    struct FloatExpr(bool);
+
+    impl Visitor for FloatExpr {
+        type Break = ();
+
+        fn enter(&mut self, this: &dyn Any) -> ControlFlow<Self::Break> {
+            if let Some(Literal::Float(_)) = this.downcast_ref::<Literal>() {
+                self.0 = true;
+            }
+            ControlFlow::Continue(())
+        }
+    }
+
+    impl VisitorMut for FloatExpr {
+        type Break = ();
+
+        fn enter_mut(&mut self, this: &mut dyn Any) -> ControlFlow<Self::Break> {
+            if let Some(Literal::Float(_)) = this.downcast_ref::<Literal>() {
+                self.0 = true;
+            }
+            ControlFlow::Continue(())
+        }
+    }
+
+    assert!({
+        let mut visitor = FloatExpr(false);
+        let _ = Literal::Null.traverse(&mut visitor);
+        !visitor.0
+    });
+
+    assert!({
+        let mut visitor = FloatExpr(false);
+        let _ = Literal::Null.traverse_mut(&mut visitor);
+        !visitor.0
+    });
+
+    assert!({
+        let mut visitor = FloatExpr(false);
+        let _ = Literal::Float(OrderedFloat(0.0)).traverse(&mut visitor);
+        visitor.0
+    });
+
+    assert!({
+        let mut visitor = FloatExpr(false);
+        let _ = Literal::Float(OrderedFloat(0.0)).traverse_mut(&mut visitor);
+        visitor.0
+    });
+}