Added bit length method on int type.

Author: windelbouwman

tests/snippets/basic_types.py

@@ -41,3 +41,10 @@
 a = complex(2, 4)
 assert type(a) is complex
 assert type(a + a) is complex
+
+
+a = 12345
+
+b = a*a*a*a*a*a*a*a
+assert b.bit_length() == 109
+

vm/src/obj/objint.rs

@@ -363,6 +363,13 @@ fn int_and(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     }
 }
 
+fn int_bit_length(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(i, Some(vm.ctx.int_type()))]);
+    let v = get_value(i);
+    let bits = v.bits();
+    Ok(vm.ctx.new_int(bits.to_bigint().unwrap()))
+}
+
 pub fn init(context: &PyContext) {
     let ref int_type = context.int_type;
     int_type.set_attr("__eq__", context.new_rustfunc(int_eq));
@@ -385,4 +392,5 @@ pub fn init(context: &PyContext) {
     int_type.set_attr("__sub__", context.new_rustfunc(int_sub));
     int_type.set_attr("__truediv__", context.new_rustfunc(int_truediv));
     int_type.set_attr("__xor__", context.new_rustfunc(int_xor));
+    int_type.set_attr("bit_length", context.new_rustfunc(int_bit_length));
 }

vm/src/stdlib/json.rs

@@ -49,8 +49,10 @@ impl<'s> serde::Serialize for PyObjectSerializer<'s> {
         } else if objtype::isinstance(self.pyobject, &self.ctx.bool_type()) {
             serializer.serialize_bool(objbool::get_value(self.pyobject))
         } else if objtype::isinstance(self.pyobject, &self.ctx.int_type()) {
-            // TODO: Figure out how to use the serialize trait on BigInt:
-            serializer.serialize_i32(objint::get_value(self.pyobject).to_i32().unwrap())
+            let v = objint::get_value(self.pyobject);
+            serializer.serialize_i64(v.to_i64().unwrap())
+        // Allthough this may seem nice, it does not give the right result:
+        // v.serialize(serializer)
         } else if objtype::isinstance(self.pyobject, &self.ctx.list_type()) {
             let elements = objlist::get_elements(self.pyobject);
             serialize_seq_elements(serializer, elements)