rustpython-vm 0.1.0

Rust Python virtual machine.
Documentation 
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use crate::obj::objstr::PyStringRef;
use crate::py_serde;
use crate::pyobject::{create_type, ItemProtocol, PyObjectRef, PyResult};
use crate::VirtualMachine;
use serde_json;

/// Implement json.dumps
pub fn json_dumps(obj: PyObjectRef, vm: &VirtualMachine) -> PyResult<String> {
    let serializer = py_serde::PyObjectSerializer::new(vm, &obj);
    serde_json::to_string(&serializer).map_err(|err| vm.new_type_error(err.to_string()))
}

/// Implement json.loads
pub fn json_loads(string: PyStringRef, vm: &VirtualMachine) -> PyResult {
    // TODO: Implement non-trivial deserialization case
    let de_result =
        py_serde::deserialize(vm, &mut serde_json::Deserializer::from_str(string.as_str()));

    de_result.map_err(|err| {
        let module = vm
            .get_attribute(vm.sys_module.clone(), "modules")
            .unwrap()
            .get_item("json", vm)
            .unwrap();
        let json_decode_error = vm.get_attribute(module, "JSONDecodeError").unwrap();
        let json_decode_error = json_decode_error.downcast().unwrap();
        let exc = vm.new_exception(json_decode_error, format!("{}", err));
        vm.set_attr(&exc, "lineno", vm.ctx.new_int(err.line()))
            .unwrap();
        vm.set_attr(&exc, "colno", vm.ctx.new_int(err.column()))
            .unwrap();
        exc
    })
}

pub fn make_module(vm: &VirtualMachine) -> PyObjectRef {
    let ctx = &vm.ctx;

    // TODO: Make this a proper type with a constructor
    let json_decode_error = create_type(
        "JSONDecodeError",
        &ctx.type_type,
        &ctx.exceptions.exception_type,
    );

    py_module!(vm, "json", {
        "dumps" => ctx.new_rustfunc(json_dumps),
        "loads" => ctx.new_rustfunc(json_loads),
        "JSONDecodeError" => json_decode_error
    })
}