From: KishoreKumar Bairi
Date: March 18 2008 9:54am
Subject: Adding Lua support to the mysql command-line client
List-Archive: http://lists.mysql.com/soc/57
Message-Id: <d75889800803180254j966539ei88366f235456de9e@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/alternative; 
	boundary="----=_Part_10532_6223533.1205834044062"

------=_Part_10532_6223533.1205834044062
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Hi..

I am happy that this year also mysql is participating in SOC.
I am interested in mysql development as part of SOC.
From the project Ideas page I found, *Adding Lua
<http://www.lua.org/>support to the
mysql command-line client *interesting.
I want to know more about this project.
and here is what I understood.
Please correct me If I am wrong and add if I'm missing something.


   - *Purpose of the project:*

This gives more flexibility to the user by providing him a feature to
execute a program(written by him in lua)
I feel this feature serves the same purpose as Shell Scripting in Unix or
m-file programs in matlab.
SQL file is also an executable script, but it is just a QUERY language and
its not like a full fledged programming lanugage
and so there comes the need for proper programming environment and this
project is going to provide it.
since we are adding support of a programming language. It enables user to
build applications using this programming language
and hence it leads to the personalization of mysql interface.


   - *Why only LUA*? :

LUA is proven to be fast,portable,small yet powerful and most importantly *
Embeddable*.
It is easy to extend Lua with libraries written in other languages.
It is also easy to extend programs written in other languages with Lua.


   - *How it works?*


   - user issues the command for lua script execution.
      - lua interpreter will be invoked.(which is *lua.c* file as
      mentioned in documentation of lua)
      - while executing the script it builds the mysql command.
      - and now we call the same functions of mysql library which are
      called when that built command was directly given on command line client.
      - So, ultimately here we are doing the same thing but prepending
      the process with an additional step.
      - (*This is just my understanding. **Please correct me if am
      wrong. **)*


   - *How this can be done?*


   - firstly I should add a feature to command line client to invoke
      interpreter when proper command for execution of lua script is given.
      - next step is regarding Lua library and interpretation. The
      library is available from Lua and Interpreter is also written by them
      - It depends on us if we are willing to use their Interpreter of
      write our own from scratch(I feel its useless to reinvent the wheel).
      - In the interpreter we have to add functionality to hand over
      the control to an intermediate(new) program(to be written).
      - this new program maps the  command command handed by
      interpreter to the mysql functionality which is supposed to be executed.
      - (*am I right?)*

*
*

   - *Qualifications:*


   - programming skills: c++,lua
      - Idea of compilers.(how they work?)
      - knowledge mysql command line client source.



   1. Am I right? If not please correct me. and guide me to know it
   better.
   2. Kindly give me some keywords or reference which would help me in
   knowing this better.

------=_Part_10532_6223533.1205834044062--