.continue() method

[faerot]

When using IndexedDB, there is a continue() method in IDBCursor object. It is impossible to use in python due to parser error as "continue" is a reserved keyword. Trivial solution is to add 'js_continue' => 'continue' default alias into modules/org/transcrypt/compiler.py. Maybe it makes sense to add all python keywords this way. At least some other keywords like js_catch which is used in promises should be added.

[mentalisttraceur]

Does getattr(foo, 'continue') work instead of foo.continue?

[faerot]

I doubt it. Transcrypt does not produce bound methods for the built-in ones. I use foo['continue']() as a work around.

[mentalisttraceur]

Ohhh, okay, I think I see. (Thanks for adding that edit - before the edit my reaction was just "why do you doubt it? based on what?")

So as I understand it now:

foo.some_method normally works in Transcrypt because it does something to make sure that the generated JavaScript binds foo to some_method.

So even if getattr(foo, 'continue') can successfully get an attribute named continue, you're thinking it won't actually do the binding, and the binding won't be done prior.

Meanwhile, foo['continue']() works because it ends up falling through to basically identical JavaScript, and the JavaScript engine sets this to foo inside the function call the same whether you write foo['bar']() or foo.bar().

But I'm a little confused why Transcrypt can't implement getattr in a way that does all the same things as normal attribute access, or why Transcrypt can't bind all methods the same way even if they have names that match keywords....

[faerot]

The difference between python and javascript in terms of calling a method is basically python has call operator () and attribute operator . so calling a method is two independent operators, while in javascript .xxx() or ['xxx']() is sort of a single operator which sets "this" and calls method.

For user defined methods transcrypt generates properties that return callable closures so this works like bound methods in python, but for built-in methods this is impossible for obvious reasons. You can do getattr(foo, 'continue')() if foo is the class defined in transcrypt, but you cannot do it for builtins.