[zem]

it's a ubiquitous pattern in ruby. this blog post uses a file open/close lifecycle manager as an example: http://yehudakatz.com/2012/01/10/javascript-needs-blocks/

[Evbn]

That's more about coroutines than first class functions, and it is RAII, using a wrapper methodd for the actor/dtor instead of defining a class.

[zem]

it is not raii as i understand the term. there is no destructor involved in closing the file, there is just a function that opens the file, passes your code the handle, then closes it when you're done.

[bowyakka]

Doesn't this amount to the same thing ?

[zem]

it accomplishes the same purpose, but the filehandle gets closed explicitly, not when it goes out of scope and its destructor gets called.