context
=======

Some resources, such as open files, have lifetimes which are better managed by
the user than by the garbage collector. The context module provides a Context
class that may be subclassed to assist in managing the lifetime of such
resources.

.. _stdlib_context_Context:

Context
-------

The Context class may be subclassed by a resource with a finite lifetime. Such
a resource may be passed to ``Context.with``, which will automatically call
``close`` on the subclass regardless of the outcome of the context function.

.. code-block:: wren

   import "context" for Context

   class MyResource is Context {
        // ...

        close() {
                System.print("closed!")
        }
   }

   Context.with(MyResource.open()) {|res|
           res.do_work()
   }

static with(res, fn)
++++++++++++++++++++

Passes the given resource to the given function, then call ``res.close()``. The
resource will be closed regardless of the outcome of the function (e.g.
aborting with an error).