1- //! Mapping protocol
2-
3- use crate :: { vm:: VirtualMachine , PyObjectRef , PyResult , TryFromBorrowedObject , TypeProtocol } ;
1+ use crate :: {
2+ builtins:: dict:: { PyDictKeys , PyDictRef , PyDictValues } ,
3+ builtins:: list:: PyList ,
4+ vm:: VirtualMachine ,
5+ IdProtocol , IntoPyObject , PyObjectRef , PyResult , TryFromBorrowedObject , TryFromObject ,
6+ TypeProtocol ,
7+ } ;
8+ use std:: borrow:: Borrow ;
9+ use std:: ops:: Deref ;
410
11+ // Mapping protocol
12+ // https://docs.python.org/3/c-api/mapping.html
513#[ allow( clippy:: type_complexity) ]
6- pub struct PyMapping {
14+ pub struct PyMappingMethods {
715 pub length : Option < fn ( PyObjectRef , & VirtualMachine ) -> PyResult < usize > > ,
816 pub subscript : Option < fn ( PyObjectRef , PyObjectRef , & VirtualMachine ) -> PyResult > ,
917 pub ass_subscript :
1018 Option < fn ( PyObjectRef , PyObjectRef , Option < PyObjectRef > , & VirtualMachine ) -> PyResult < ( ) > > ,
1119}
1220
13- impl PyMapping {
14- pub fn check ( cls : & PyObjectRef , vm : & VirtualMachine ) -> bool {
15- if let Ok ( mapping) = PyMapping :: try_from_borrowed_object ( vm, cls) {
16- mapping. subscript . is_some ( )
17- } else {
18- false
19- }
20- }
21- }
22-
23- impl TryFromBorrowedObject for PyMapping {
21+ impl TryFromBorrowedObject for PyMappingMethods {
2422 fn try_from_borrowed_object ( vm : & VirtualMachine , obj : & PyObjectRef ) -> PyResult < Self > {
2523 let obj_cls = obj. class ( ) ;
2624 for cls in obj_cls. iter_mro ( ) {
@@ -34,3 +32,111 @@ impl TryFromBorrowedObject for PyMapping {
3432 ) ) )
3533 }
3634}
35+
36+ #[ derive( Debug , Clone ) ]
37+ #[ repr( transparent) ]
38+ pub struct PyMapping < T = PyObjectRef > ( T )
39+ where
40+ T : Borrow < PyObjectRef > ;
41+
42+ impl PyMapping < PyObjectRef > {
43+ pub fn into_object ( self ) -> PyObjectRef {
44+ self . 0
45+ }
46+
47+ pub fn check ( obj : & PyObjectRef , vm : & VirtualMachine ) -> bool {
48+ if let Ok ( mapping) = PyMappingMethods :: try_from_borrowed_object ( vm, obj) {
49+ mapping. subscript . is_some ( )
50+ } else {
51+ false
52+ }
53+ }
54+ }
55+
56+ impl < T > PyMapping < T >
57+ where
58+ T : Borrow < PyObjectRef > ,
59+ {
60+ pub fn new ( obj : T ) -> Self {
61+ Self ( obj)
62+ }
63+
64+ pub fn keys ( & self , vm : & VirtualMachine ) -> PyResult {
65+ if self . 0 . borrow ( ) . is ( & vm. ctx . types . dict_type ) {
66+ Ok (
67+ PyDictKeys :: new ( PyDictRef :: try_from_object ( vm, self . 0 . borrow ( ) . clone ( ) ) ?)
68+ . into_pyobject ( vm) ,
69+ )
70+ } else {
71+ Self :: method_output_as_list ( self . 0 . borrow ( ) , "keys" , vm)
72+ }
73+ }
74+
75+ pub fn values ( & self , vm : & VirtualMachine ) -> PyResult {
76+ if self . 0 . borrow ( ) . is ( & vm. ctx . types . dict_type ) {
77+ Ok (
78+ PyDictValues :: new ( PyDictRef :: try_from_object ( vm, self . 0 . borrow ( ) . clone ( ) ) ?)
79+ . into_pyobject ( vm) ,
80+ )
81+ } else {
82+ Self :: method_output_as_list ( self . 0 . borrow ( ) , "values" , vm)
83+ }
84+ }
85+
86+ fn method_output_as_list (
87+ obj : & PyObjectRef ,
88+ method_name : & str ,
89+ vm : & VirtualMachine ,
90+ ) -> PyResult {
91+ let meth_output = vm. call_method ( obj, method_name, ( ) ) ?;
92+ if meth_output. is ( & vm. ctx . types . list_type ) {
93+ return Ok ( meth_output) ;
94+ }
95+
96+ let iter = meth_output. clone ( ) . get_iter ( vm) . map_err ( |_| {
97+ vm. new_type_error ( format ! (
98+ "{}.{}() returned a non-iterable (type {})" ,
99+ obj. class( ) ,
100+ method_name,
101+ meth_output. class( )
102+ ) )
103+ } ) ?;
104+
105+ Ok ( PyList :: from ( vm. extract_elements ( & iter) ?) . into_pyobject ( vm) )
106+ }
107+ }
108+
109+ impl < T > Borrow < PyObjectRef > for PyMapping < T >
110+ where
111+ T : Borrow < PyObjectRef > ,
112+ {
113+ fn borrow ( & self ) -> & PyObjectRef {
114+ self . 0 . borrow ( )
115+ }
116+ }
117+
118+ impl < T > Deref for PyMapping < T >
119+ where
120+ T : Borrow < PyObjectRef > ,
121+ {
122+ type Target = PyObjectRef ;
123+ fn deref ( & self ) -> & Self :: Target {
124+ self . 0 . borrow ( )
125+ }
126+ }
127+
128+ impl IntoPyObject for PyMapping < PyObjectRef > {
129+ fn into_pyobject ( self , _vm : & VirtualMachine ) -> PyObjectRef {
130+ self . into_object ( )
131+ }
132+ }
133+
134+ impl TryFromObject for PyMapping < PyObjectRef > {
135+ fn try_from_object ( vm : & VirtualMachine , mapping : PyObjectRef ) -> PyResult < Self > {
136+ if Self :: check ( & mapping, vm) {
137+ Ok ( Self :: new ( mapping) )
138+ } else {
139+ Err ( vm. new_type_error ( format ! ( "{} is not a mapping object" , mapping. class( ) ) ) )
140+ }
141+ }
142+ }
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