[Tutor] Meta language and code generation

[Knacktus]

Am 01.04.2011 20:56, schrieb Karim:
> On 04/01/2011 08:29 PM, Knacktus wrote:
>> Am 01.04.2011 19:09, schrieb Karim:
>>>
>>> Hello All,
>>>
>>> I would to ask you if somebody has experience or can give direction in a
>>> new project I have.
>>> I have a meta language description (in xml) from which I should generate
>>> code on different
>>> languages. In my case, lisp and tcl.
>>
>> You need to provide more information of your description to get some
>> specific hints. The other day a had a xml file containing a business
>> object model with hierarchy and relations. Then I wrote a code
>> generator to build a module with Python classes for each business
>> item. The code generator created properties for lazily resolving
>> relations modelled via ids in the database and stuff like that. This
>> was very straightforeward using a simple print statements like the
>> following:
>>
>> print "class %s(object):\n" % class_name
>> print " def __init__(self, %s)" % constr_arg
>> ...
>>
>> Cheers,
>>
>> Jan
>
>
> In fact in xml I have something like that:
>
> A metafunction in fact kind of
>
> <metfunc name=call_back_do_stuff_function>
> <parameter>x</parameter>
> <parameter>y</parameter>
> </metafunc>
>
>
> I have to generate the call_back_do_stuff_function(x,y) in lisp and tcl
> according to a catalog of specs
> of what this function must do generically.
>
> I can do prints for each metafunctio I read but my concern is is there
> std libs to help to have good design
> and methodology. Is it interesting to use command module of something
> like that, is interesting to use
> a parser like pylex or pyparsing? I have 50 metafunctions in catalog for
> now.
>
> In fact, my point is to have a great extensive design methodology.
> Strategy pattern would suit?
> Other patterns? std modules?


No ideas about patterns or standarad lib modules from my side, but a 
short description of how I would do it:

Create an abstraction for the catalogue. That's as far as I can see the 
hardest part. Here you have to decide if and how to split the things 
your functions have to do into reusable chunks. Then create code 
generators for these chunks (using print statements). You can name these 
functions and store the references in dicts like 
catalog_comp_name_to_tcl_gen. If you get new functions that need new 
building blocks you can write new generator functions and extend your 
dictionaries.

The generation of your tcl and lisp "functions-frames" should be straigt 
forward. You need to link the parameters to the building block generator 
functions you've created before.

When you're done with that, you can improve the design step by step. Too 
me, this approach works better than thinking to much about design in 
advance, as often you don't see what you really need unless you've 
started to code.

HTH,

Jan



>
> Lots of question here!
>
> Regards
> Karim
>
>
>>
>>>
>>> Any idea in term of design, examples, links will be appreciated!
>>>
>>> Kind Regards
>>> Karim
>>> _______________________________________________
>>> Tutor maillist - Tutor at python.org
>>> To unsubscribe or change subscription options:
>>> http://mail.python.org/mailman/listinfo/tutor
>>
>> _______________________________________________
>> Tutor maillist - Tutor at python.org
>> To unsubscribe or change subscription options:
>> http://mail.python.org/mailman/listinfo/tutor
>
> _______________________________________________
> Tutor maillist - Tutor at python.org
> To unsubscribe or change subscription options:
> http://mail.python.org/mailman/listinfo/tutor