Format Rules
============


Basic definition
****************

Format rules are rules that define how the result of the execution must be printed.
I guess that it will be ultimately be replaced / transformed into the program that can speak


::

    > when <predicate> print <action>

where:

    predicate is a valid sheerka syntax

    action is a custom language defined below


Action
*******

::

    ACTION := FUNCTION | VARIABLE | RAW
    FUNCTION := IDENT \( PARAM* (, PARAM)* \)
    PARAM :=
    VARIABLE := \{PREFIX:IDENT \}
    PREFIX :=
    RAW :=

Some examples

::

    blue(digest) : {command}\nlist(body) 


Predicate
*********
The predicate indicates the conditions to trigger the print / formatting
You can use the whole Sheerka language (methods and Concepts)

In addition to the regular function, you have also access to local variables

+-----------------+-------------------------------------------------------------------------------------------------------------------------+
| Name            | Definition                                                                                                              |
+=================+=========================================================================================================================+
| __obj           |  The current object being processed                                                                                     |
+-----------------+-------------------------------------------------------------------------------------------------------------------------+
| __ret           | current object if it is a ``ReturnValueConcept``                                                                        |
+-----------------+-------------------------------------------------------------------------------------------------------------------------+
| __ret_value     |                                                                                                                         |
|                 |  * current value's body if the current value is a ``ReturnValueConcept``                                                |
|                 |  * current value's body's body if the current value is a ``ReturnValueConcept`` and the body is a container concept     |
|                 |  * current value otherwise                                                                                              |
+-----------------+-------------------------------------------------------------------------------------------------------------------------+
| __ret_container | When the current value is a ``ReturnValueConcept`` and its body is a container concept such as                          |
|                 |     * ``ParserResultConcept``                                                                                           |
|                 |     * ``ErrorConcept``                                                                                                  |
|                 |     * ``OnlySuccessfulConcept``                                                                                         |
|                 |     * ...                                                                                                               |
+-----------------+-------------------------------------------------------------------------------------------------------------------------+