Re:Implementing Go's defer keyword in C++
by tedunangst on Saturday October 21, 2017 @09:18PM
(#15524578)
But how does that close over other locals? I'll admit I haven't looked too closely, but go defer makes it pretty easy to drop in a lambda. Getting stuff into your decorated functions by reference is going to be awkward, unless I'm missing something.
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Re:Implementing Go's defer keyword in C++
by masklinn on Sunday October 22, 2017 @06:49AM
(#15526122)
> But how does that close over other locals?
It does not, it works like a C++ destructor, the context management code is static, and anything it needs is provided as a parameter.
While "ad-hoc" context managers are possible (and quite trivial in fact):
1. I don't remember ever wanting one
2. they would not be convenient owing to Python's limited lambdas so
3. you'd probably implement them using a ~decorator on a nested function instead which
4. may look quite odd to most Python developers
Re:Implementing Go's defer keyword in C++
by eesmith on Sunday October 22, 2017 @06:26AM
(#15526041)
I'll need to see an example to understand the issue. The idioms between the two languages are different enough that idiomatic Go might be written a different way for idiomatic Python.
Remember, "with" isn't always required - you can also write the code using a try/finally.