problem with invert operator expression

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
javascript, python
Domain
compilers

Research direction

Start with the provided Python sample and compare the two generated JavaScript forms in a Firefox 133 environment. Trace how the compiler handles ~(obj) versus the __invert__() method call; done means the operator expression dispatches correctly without the reported TypeError and the behavior has a regression check.

Written by the indexing model from the issue text.

Description

IS: bug?

Expression with invert operator of an class instance causes error.

Error occurs with iobj = ~(obj) expression.
Browser error: Uncaught TypeError: Function.prototype.toString called on incompatible object.
Worked properly with iobj = obj.__invert__() expression.

python code:

class Obj:
    def __init__(self, x):
        self.x = x
    def __invert__(self):
        return ~self.x

# __pragma__ ('opov')
def op_invert():
    obj = Obj(42)
    if False:
        iobj = ~(obj)
# __pragma__ ('noopov')

op_invert()

compiled javascript code with ~(obj):

export var op_invert = function () {
	var obj = __call__ (Obj, null, 10);
	var iobj = ~(obj);
};

compiled javascript code with obj.__invert__():

export var op_invert = function () {
	var obj = __call__ (Obj, null, 10);
	var iobj = (function () {
		var __accu0__ = obj;
		return __call__ (__accu0__.__invert__, __accu0__);
	}) ();
};

env: Python3.9 venv with pip install Transcrypt
testing: Firefox version 133 in Linux

Dominant language
Python
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