File syntax
###########

The Lpy file format is based on the python language which is extended with L-system particular constructs.


.. _FileSyntax_Canvas_Of_LPy_File:

Canvas of L-Py file
===================

.. code-block:: python

    # pure python code
    def func():
       # python code
       nproduce lstring # it is possible to use the nproduce statement
                        # in this part of the file

    module A,B   # declaration of module name

    Axiom: lstring # declaration of axiom

    derivation length: int # default = 1
                           # number of derivation step to perform
    production: # beginning of production rules

    pattern :          # a production rule. Start with successor given as a pattern of module to replace
       python code     # rule core are pure python code with production statement
       produce lstring # production statement giving the new string pattern to produce

    # simple rules can be expressed this way
    pattern --> new_pattern

    homomorphism: # beginning of homomorphism rules.
                  # They are called before plotting the string or
                  # application of rule with query modules (?[PHUR])
    maximum depth: int # default = 1
                       # number of homomorphism recursive step to perform.
                       # should be defined only once

    decomposition: # beginning of decomposition rules.
                   # These rules are applied recursively after each production step
                   # usefull to decompose a module into a structure
    maximum depth: int # default = 1
                       # number of decomposition recursive step to perform.
                       # should be defined only once

    group: int  # all following rules will be assign to this group
                # to activate a group of rule see command useGroup
                # by default group 0 is active

    production: # again all types of rule can be defined
    homomorphism:
    decomposition:

    endgroup # following rules will be assign to default 0 group

    production: # again all types of rule can be defined
    homomorphism:
    decomposition:

    endlsystem # end of rules definition

    # pure python code is again possible


.. _FileSyntax_LSystem_Specific_Declaration:

L-System specific declaration
=============================

+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**module name**             |*Declaration of module name.*                                                                                                                                                                            |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**consider: name**          |*Symbol to consider.*                                                                                                                                                                                    |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**ignore: name**            |*Symbol to ignore.*                                                                                                                                                                                      |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**group id:**               |*Following rules will be associated to group id. By default rules are associated to group 0.*                                                                                                            |
|                            |*The rules of this group will always be applied. To additionnally activate other groups, use the command useGroup.*                                                                                          |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**Axiom: Lstring**          |*Declaration of the axiom of the Lsystem*                                                                                                                                                                |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**produce Lstring**         |*Produce an Lstring and return.*                                                                                                                                                                         |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**nproduce Lstring**        |*Produce an Lstring whithout returning.*                                                                                                                                                                 |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**derivation length: value**|*Number of derivation to do (default=1).*                                                                                                                                                                |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**production:**             |*Start of the production rules declaration.*                                                                                                                                                             |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**homomorphism:**           |*Start of the interpretation rules declaration.*                                                                                                                                                         |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**interpretation:**         |*Start of the interpretation rules declaration.*                                                                                                                                                         |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**decomposition:**          |*Start of the decomposition rules declaration.*                                                                                                                                                          |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**maximum depth:**          |*Number of decomposition or interpretation recursive call to do (default=1).*                                                                                                                            |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**endgroup**                |*Reactivate default group 0.*                                                                                                                                                                            |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|**endlsystem**              |*End of lsystem rules declaration.*                                                                                                                                                                      |
+----------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+