Error in evaluation of function default arguments

[faerot]

x = []

for i in range(5):
    x.append(lambda i=i: print(i))

for c in x:
    c()

python output:

0
1
2
3
4

javascript output:

undefined
undefined
undefined
undefined
undefined

The problem is transcrypt postpones evaluation of default arguments to inside function:

export var x = [];
for (var i = 0; i < 5; i++) {
    x.append ((function __lambda__ (i) {
        if (typeof i == 'undefined' || (i != null && i.hasOwnProperty ("__kwargtrans__"))) {;
            var i = i;
        };
        return print (i);
    }));
}
for (var c of x) {
    c ();
}

To fix it we need to wrap function declaration in another closure and have default values locked inside that function call like this:

export var x = [];
for (var i = 0; i < 5; i++) {
    x.append (
    (function() {
        var default_i = i;
        return (function __lambda__ (i) {
            if (typeof i == 'undefined' || (i != null && i.hasOwnProperty ("__kwargtrans__"))) {
                var i = default_i;
            };
            return print (i);
        });
    })()
    
    );
}
for (var c of x) {
    c ();
}

[faerot]

Ok, looks like it was already reviewed 3 years ago here: https://github.com/QQuick/Transcrypt/issues/36 and it was suggested to consider it a transcrypt "limitation", but what about my suggested solution above? This requires minimal overhead but should provide correct behavior with python.

[JdeH]

I find the current limitation very annoying and will take a good look at your solution!

[trenta3]

Is there any update on this issue? This basically prevents using partially evaluated functions to pass around as values. In my usage this is pretty worrysome!