Why not just use try/after? ...Paul
On Fri, Aug 5, 2016 at 10:39 AM, Filip Haglund <[email protected]> wrote: > I often find myself writing > > def func(a,b): > g = :digraph.new > > ... > > out = some_long_multiline_expression_using_g > :digraph.delete g > out > end > > when working with graphs. The distance between `:digraph.new` and > `:digraph.delete` makes it harder to remember to clean up the graph ets > tables. The little dance at the end to return a value and also clean up the > mutable state feels a bit awkward too. This problem is common when working > with mutex, files and other things you need to remember to clean up. Golang > has a great solution; the `defer` statement > <https://golang.org/ref/spec#Defer_statements>. > > def func(a,b): > g = :digraph.new > defer :digraph.delete g > > ... > > some_long_multiline_expression_using_g > end > > This minimizes the distance between declaration and cleanup statement, > makes it harder to forget it, and also cleans up the end of the function. > If there isn't a `defer` just after some mutable state is created, you > immediately know that you need to figure out where the mutable state is > cleaned up. If there is a `defer` statement there, you can read the rest of > the code without having to think about if every branch has the proper > clean-up code in it. > > Each `defer` statement pushes a function call onto a stack, with the > variable bindings it had when the `defer` statement was reached. When the > function returns, the function calls on the stack are executed one by one. > > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/elixir-lang-core/2c0d8195-ec44-4112-a0c1- > 2f5c5f3905b2%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/2c0d8195-ec44-4112-a0c1-2f5c5f3905b2%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CAD3kWz_ELjAM13pqA-xuCoizB1gKwQUnPUtepxnNRw9bE5eNDA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
