Merge pull request RustPython#3901 from rimi0108/add-dict-mapping

Add a mapping property

Author: youknowone

vm/src/builtins/dict.rs

@@ -1,6 +1,6 @@
 use super::{
-    set::PySetInner, IterStatus, PositionIterInternal, PyBaseExceptionRef, PyGenericAlias, PySet,
-    PyStrRef, PyTupleRef, PyType, PyTypeRef,
+    set::PySetInner, IterStatus, PositionIterInternal, PyBaseExceptionRef, PyGenericAlias,
+    PyMappingProxy, PySet, PyStrRef, PyTupleRef, PyType, PyTypeRef,
 };
 use crate::{
     builtins::{
@@ -1041,6 +1041,11 @@ impl PyDictKeys {
     fn contains(zelf: PyRef<Self>, key: PyObjectRef, vm: &VirtualMachine) -> PyResult<bool> {
         zelf.dict().contains(key, vm)
     }
+
+    #[pyproperty]
+    fn mapping(zelf: PyRef<Self>) -> PyMappingProxy {
+        PyMappingProxy::from(zelf.dict().clone())
+    }
 }
 impl Unconstructible for PyDictKeys {}
 
@@ -1090,6 +1095,10 @@ impl PyDictItems {
         let found = PyDict::getitem(zelf.dict().clone(), key, vm)?;
         vm.identical_or_equal(&found, &value)
     }
+    #[pyproperty]
+    fn mapping(zelf: PyRef<Self>) -> PyMappingProxy {
+        PyMappingProxy::from(zelf.dict().clone())
+    }
 }
 impl Unconstructible for PyDictItems {}
 
@@ -1118,7 +1127,12 @@ impl AsSequence for PyDictItems {
 }
 
 #[pyimpl(with(DictView, Constructor, Iterable, AsSequence))]
-impl PyDictValues {}
+impl PyDictValues {
+    #[pyproperty]
+    fn mapping(zelf: PyRef<Self>) -> PyMappingProxy {
+        PyMappingProxy::from(zelf.dict().clone())
+    }
+}
 impl Unconstructible for PyDictValues {}
 
 impl AsSequence for PyDictValues {

vm/src/builtins/mappingproxy.rs

@@ -1,4 +1,4 @@
-use super::{PyDict, PyGenericAlias, PyList, PyTuple, PyType, PyTypeRef};
+use super::{PyDict, PyDictRef, PyGenericAlias, PyList, PyTuple, PyType, PyTypeRef};
 use crate::{
     class::PyClassImpl,
     convert::ToPyObject,
@@ -26,10 +26,18 @@ impl PyPayload for PyMappingProxy {
     }
 }
 
-impl PyMappingProxy {
-    pub fn new(class: PyTypeRef) -> Self {
+impl From<PyTypeRef> for PyMappingProxy {
+    fn from(dict: PyTypeRef) -> Self {
+        Self {
+            mapping: MappingProxyInner::Class(dict),
+        }
+    }
+}
+
+impl From<PyDictRef> for PyMappingProxy {
+    fn from(dict: PyDictRef) -> Self {
         Self {
-            mapping: MappingProxyInner::Class(class),
+            mapping: MappingProxyInner::Mapping(ArgMapping::from_dict_exact(dict)),
         }
     }
 }

vm/src/builtins/type.rs

@@ -576,7 +576,7 @@ impl PyType {
 
     #[pyproperty(magic)]
     fn dict(zelf: PyRef<Self>) -> PyMappingProxy {
-        PyMappingProxy::new(zelf)
+        PyMappingProxy::from(zelf)
     }
 
     #[pyproperty(magic, setter)]