Merge pull request #1278 from davidhewitt/pytypeinfo-check

pytypeinfo: rename is_instance to is_type_of

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Change formatting of `PyDowncastError` messages to be closer to Python's builtin error messages. [#1212](https://github.com/PyO3/pyo3/pull/1212)
 - Change `Debug` and `Display` impls for `PyException` to be consistent with `PyAny`. [#1275](https://github.com/PyO3/pyo3/pull/1275)
 - Change `Debug` impl of `PyErr` to output more helpful information (acquiring the GIL if necessary). [#1275](https://github.com/PyO3/pyo3/pull/1275)
+- Rename `PyTypeInfo::is_instance` and `PyTypeInfo::is_exact_instance` to `PyTypeInfo::is_type_of` and `PyTypeInfo::is_exact_type_of`. [#1278](https://github.com/PyO3/pyo3/pull/1278)
 
 ### Removed
 - Remove deprecated ffi definitions `PyUnicode_AsUnicodeCopy`, `PyUnicode_GetMax`, `_Py_CheckRecursionLimit`, `PyObject_AsCharBuffer`, `PyObject_AsReadBuffer`, `PyObject_CheckReadBuffer` and `PyObject_AsWriteBuffer`, which will be removed in Python 3.10. [#1217](https://github.com/PyO3/pyo3/pull/1217)

src/conversion.rs

@@ -326,7 +326,7 @@ where
     fn try_from<V: Into<&'v PyAny>>(value: V) -> Result<&'v Self, PyDowncastError<'v>> {
         let value = value.into();
         unsafe {
-            if T::is_instance(value) {
+            if T::is_type_of(value) {
                 Ok(Self::try_from_unchecked(value))
             } else {
                 Err(PyDowncastError::new(value, T::NAME))
@@ -337,7 +337,7 @@ where
     fn try_from_exact<V: Into<&'v PyAny>>(value: V) -> Result<&'v Self, PyDowncastError<'v>> {
         let value = value.into();
         unsafe {
-            if T::is_exact_instance(value) {
+            if T::is_exact_type_of(value) {
                 Ok(Self::try_from_unchecked(value))
             } else {
                 Err(PyDowncastError::new(value, T::NAME))
@@ -358,7 +358,7 @@ where
     fn try_from<V: Into<&'v PyAny>>(value: V) -> Result<&'v Self, PyDowncastError<'v>> {
         let value = value.into();
         unsafe {
-            if T::is_instance(value) {
+            if T::is_type_of(value) {
                 Ok(Self::try_from_unchecked(value))
             } else {
                 Err(PyDowncastError::new(value, T::NAME))
@@ -368,7 +368,7 @@ where
     fn try_from_exact<V: Into<&'v PyAny>>(value: V) -> Result<&'v Self, PyDowncastError<'v>> {
         let value = value.into();
         unsafe {
-            if T::is_exact_instance(value) {
+            if T::is_exact_type_of(value) {
                 Ok(Self::try_from_unchecked(value))
             } else {
                 Err(PyDowncastError::new(value, T::NAME))
@@ -434,11 +434,39 @@ where
 
 #[cfg(test)]
 mod test {
-    use crate::types::PyList;
-    use crate::Python;
+    use crate::types::{IntoPyDict, PyAny, PyDict, PyList};
+    use crate::{Python, ToPyObject};
 
     use super::PyTryFrom;
 
+    #[test]
+    fn test_try_from() {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
+        let list: &PyAny = vec![3, 6, 5, 4, 7].to_object(py).into_ref(py);
+        let dict: &PyAny = vec![("reverse", true)].into_py_dict(py).as_ref();
+
+        assert!(PyList::try_from(list).is_ok());
+        assert!(PyDict::try_from(dict).is_ok());
+
+        assert!(PyAny::try_from(list).is_ok());
+        assert!(PyAny::try_from(dict).is_ok());
+    }
+
+    #[test]
+    fn test_try_from_exact() {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
+        let list: &PyAny = vec![3, 6, 5, 4, 7].to_object(py).into_ref(py);
+        let dict: &PyAny = vec![("reverse", true)].into_py_dict(py).as_ref();
+
+        assert!(PyList::try_from_exact(list).is_ok());
+        assert!(PyDict::try_from_exact(dict).is_ok());
+
+        assert!(PyAny::try_from_exact(list).is_err());
+        assert!(PyAny::try_from_exact(dict).is_err());
+    }
+
     #[test]
     fn test_try_from_unchecked() {
         let gil = Python::acquire_gil();

src/type_object.rs

@@ -104,13 +104,13 @@ pub unsafe trait PyTypeInfo: Sized {
     /// PyTypeObject instance for this type.
     fn type_object_raw(py: Python) -> *mut ffi::PyTypeObject;
 
-    /// Check if `*mut ffi::PyObject` is instance of this type
-    fn is_instance(object: &PyAny) -> bool {
+    /// Checks if `object` is an instance of this type or a subclass of this type.
+    fn is_type_of(object: &PyAny) -> bool {
         unsafe { ffi::PyObject_TypeCheck(object.as_ptr(), Self::type_object_raw(object.py())) != 0 }
     }
 
-    /// Check if `*mut ffi::PyObject` is exact instance of this type
-    fn is_exact_instance(object: &PyAny) -> bool {
+    /// Checks if `object` is an instance of this type.
+    fn is_exact_type_of(object: &PyAny) -> bool {
         unsafe { ffi::Py_TYPE(object.as_ptr()) == Self::type_object_raw(object.py()) }
     }
 }

src/types/mod.rs

@@ -184,7 +184,7 @@ macro_rules! pyobject_native_type_convert(
             }
 
             #[allow(unused_unsafe)]
-            fn is_instance(ptr: &$crate::PyAny) -> bool {
+            fn is_type_of(ptr: &$crate::PyAny) -> bool {
                 use $crate::AsPyPointer;
                 unsafe { $checkfunction(ptr.as_ptr()) > 0 }
             }