.. _stdlib_cross_context:

==================================================================
A module required after the walk, and calls into its macro context
==================================================================

.. das:module:: cross_context

The CROSS_CONTEXT module requires a ``shared`` module after the prerequisite walk -
from a macro, a simulate macro or an ``[init]``, never from a running script, which has
no compile for the module to join - and calls into its macro context by function name,
so a module that is expensive to bring up and only sometimes needed comes in at the point
that decides it needs it.

The function reached by name is ``[export]``\ ed - a macro context keeps only exported,
``[init]``, ``[finalize]`` and macro-init functions - and it runs under the target
context's lock, so it must not call back into the calling context; everything the caller
needs comes back through the result pointer.

All functions and symbols are in "cross_context" module, use require to get access to it.

.. code-block:: das

    require daslib/cross_context



++++++++++++
Late require
++++++++++++

  *  :ref:`macro_context_of (name: string) : Context? <function-cross_context_macro_context_of_string>`
  *  :ref:`require_module_now (name: string) : Module? <function-cross_context_require_module_now_string>`

.. _function-cross_context_macro_context_of_string:

.. das:function:: macro_context_of(name: string) : Context?

The macro context of the shared module `name`, required now when the process lacks
it; null, logged, when the module has no macros.


:Arguments: * **name** : string

.. _function-cross_context_require_module_now_string:

.. das:function:: require_module_now(name: string) : Module?

Compiles `name` - a `shared` module - and its prerequisites now, under the compiling
program's policies and file access, or answers the one already in the process; a panic
outside a compile (a macro, a simulate macro, an `[init]`). Null, logged, on failure.


:Arguments: * **name** : string