Merge pull request #236 from coolreader18/proper-dict

Make `dict()` work like it does in cpython

tests/snippets/dict.py

@@ -0,0 +1,16 @@
+def dict_eq(d1, d2):
+    return (all(k in d2 and d1[k] == d2[k] for k in d1)
+            and all(k in d1 and d1[k] == d2[k] for k in d2))
+
+
+assert dict_eq(dict(a=2, b=3), {'a': 2, 'b': 3})
+assert dict_eq(dict({'a': 2, 'b': 3}, b=4), {'a': 2, 'b': 4})
+assert dict_eq(dict([('a', 2), ('b', 3)]), {'a': 2, 'b': 3})
+
+a = {'g': 5}
+b = {'a': a, 'd': 9}
+c = dict(b)
+c['d'] = 3
+c['a']['g'] = 2
+assert dict_eq(a, {'g': 2})
+assert dict_eq(b, {'a': a, 'd': 9})

vm/src/obj/objdict.rs

@@ -2,6 +2,7 @@ use super::super::pyobject::{
     PyContext, PyFuncArgs, PyObject, PyObjectKind, PyObjectRef, PyResult, TypeProtocol,
 };
 use super::super::vm::VirtualMachine;
+use super::objiter;
 use super::objstr;
 use super::objtype;
 use num_bigint::ToBigInt;
@@ -113,8 +114,43 @@ pub fn content_contains_key_str(elements: &DictContentType, key: &str) -> bool {
 
 // Python dict methods:
 
-fn dict_new(_vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
-    Ok(new(args.args[0].clone()))
+fn dict_new(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(
+        vm,
+        args,
+        required = [(_ty, Some(vm.ctx.type_type()))],
+        optional = [(dict_obj, None)]
+    );
+    let dict = vm.ctx.new_dict();
+    if let Some(dict_obj) = dict_obj {
+        if objtype::isinstance(&dict_obj, &vm.ctx.dict_type()) {
+            for (needle, value) in get_key_value_pairs(&dict_obj) {
+                set_item(&dict, &needle, &value);
+            }
+        } else {
+            let iter = objiter::get_iter(vm, dict_obj)?;
+            loop {
+                fn err(vm: &mut VirtualMachine) -> PyObjectRef {
+                    vm.new_type_error("Iterator must have exactly two elements".to_string())
+                }
+                let element = match objiter::get_next_object(vm, &iter)? {
+                    Some(obj) => obj,
+                    None => break,
+                };
+                let elem_iter = objiter::get_iter(vm, &element)?;
+                let needle = objiter::get_next_object(vm, &elem_iter)?.ok_or_else(|| err(vm))?;
+                let value = objiter::get_next_object(vm, &elem_iter)?.ok_or_else(|| err(vm))?;
+                if let Some(_) = objiter::get_next_object(vm, &elem_iter)? {
+                    return Err(err(vm));
+                }
+                set_item(&dict, &needle, &value);
+            }
+        }
+    }
+    for (needle, value) in args.kwargs {
+        set_item(&dict, &vm.new_str(needle), &value);
+    }
+    Ok(dict)
 }
 
 fn dict_len(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {