1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129

use super::objdict::PyDictRef;
use super::objiter;
use super::objstr::PyStringRef;
use super::objtype::PyClassRef;
use crate::function::OptionalArg;
use crate::pyobject::{
    ItemProtocol, PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject,
};
use crate::vm::VirtualMachine;

#[pyclass]
#[derive(Debug)]
pub struct PyMappingProxy {
    mapping: MappingProxyInner,
}

#[derive(Debug)]
enum MappingProxyInner {
    Class(PyClassRef),
    Dict(PyObjectRef),
}

pub type PyMappingProxyRef = PyRef<PyMappingProxy>;

impl PyValue for PyMappingProxy {
    fn class(vm: &VirtualMachine) -> PyClassRef {
        vm.ctx.types.mappingproxy_type.clone()
    }
}

#[pyimpl]
impl PyMappingProxy {
    pub fn new(class: PyClassRef) -> PyMappingProxy {
        PyMappingProxy {
            mapping: MappingProxyInner::Class(class),
        }
    }

    #[pyslot]
    fn tp_new(cls: PyClassRef, mapping: PyObjectRef, vm: &VirtualMachine) -> PyResult<PyRef<Self>> {
        PyMappingProxy {
            mapping: MappingProxyInner::Dict(mapping),
        }
        .into_ref_with_type(vm, cls)
    }

    fn get_inner(&self, key: PyObjectRef, vm: &VirtualMachine) -> PyResult<Option<PyObjectRef>> {
        let opt = match &self.mapping {
            MappingProxyInner::Class(class) => {
                let key = PyStringRef::try_from_object(vm, key)?;
                class.get_attr(key.as_str())
            }
            MappingProxyInner::Dict(obj) => obj.get_item(&key, vm).ok(),
        };
        Ok(opt)
    }

    #[pymethod]
    fn get(&self, key: PyObjectRef, default: OptionalArg, vm: &VirtualMachine) -> PyResult {
        let default = default.into_option();
        Ok(self
            .get_inner(key, vm)?
            .or(default)
            .unwrap_or_else(|| vm.get_none()))
    }

    #[pymethod(name = "__getitem__")]
    pub fn getitem(&self, key: PyObjectRef, vm: &VirtualMachine) -> PyResult {
        self.get_inner(key.clone(), vm)?
            .ok_or_else(|| vm.new_key_error(key))
    }

    #[pymethod(name = "__contains__")]
    pub fn contains(&self, key: PyObjectRef, vm: &VirtualMachine) -> PyResult {
        match &self.mapping {
            MappingProxyInner::Class(class) => {
                let key = PyStringRef::try_from_object(vm, key)?;
                Ok(vm.new_bool(class.has_attr(key.as_str())))
            }
            MappingProxyInner::Dict(obj) => vm._membership(obj.clone(), key),
        }
    }

    #[pymethod(name = "__iter__")]
    pub fn iter(&self, vm: &VirtualMachine) -> PyResult {
        let obj = match &self.mapping {
            MappingProxyInner::Dict(d) => d.clone(),
            MappingProxyInner::Class(c) => {
                // TODO: something that's much more efficient than this
                PyDictRef::from_attributes(c.attributes.borrow().clone(), vm)?.into_object()
            }
        };
        objiter::get_iter(vm, &obj)
    }
    #[pymethod]
    pub fn items(&self, vm: &VirtualMachine) -> PyResult {
        let obj = match &self.mapping {
            MappingProxyInner::Dict(d) => d.clone(),
            MappingProxyInner::Class(c) => {
                PyDictRef::from_attributes(c.attributes.borrow().clone(), vm)?.into_object()
            }
        };
        vm.call_method(&obj, "items", vec![])
    }
    #[pymethod]
    pub fn keys(&self, vm: &VirtualMachine) -> PyResult {
        let obj = match &self.mapping {
            MappingProxyInner::Dict(d) => d.clone(),
            MappingProxyInner::Class(c) => {
                PyDictRef::from_attributes(c.attributes.borrow().clone(), vm)?.into_object()
            }
        };
        vm.call_method(&obj, "keys", vec![])
    }
    #[pymethod]
    pub fn values(&self, vm: &VirtualMachine) -> PyResult {
        let obj = match &self.mapping {
            MappingProxyInner::Dict(d) => d.clone(),
            MappingProxyInner::Class(c) => {
                PyDictRef::from_attributes(c.attributes.borrow().clone(), vm)?.into_object()
            }
        };
        vm.call_method(&obj, "values", vec![])
    }
}

pub fn init(context: &PyContext) {
    PyMappingProxy::extend_class(context, &context.types.mappingproxy_type)
}