gsl_example

See README.pdf

If you are looking for usage examples of the FOR&IF control flow statement of iMatix GSL code generator, I created a simplified C program functions model in XML and use GSL to generate C header and source files.

GSL can be found here https://github.com/imatix/gsl (1) GSL specification can be found here https://imatix-legacy.github.io/gslgen/gsldoc4.htm (2)

Demo

The GSL application concept for the demo

 (cppsystem.xml)      (cppsystem.gsl, cmake,gsl, main,gsl,
                           service_cpp.gsl, service_h.gsl)
       XML ------ 1..* -- GSL template 
        |
        1
        |
        |
        |
  GSL command line ------ * -- output text file 
                            (CMakeLists.txt, ex_serv1.cpp, ex_serv2.cpp
                              serv1.cpp, serv1.h, serv2.cpp, serv2.h) 
        

GSL command line program

You will have to install the GSL command line program. GSL installation guide can be found here https://github.com/imatix/gsl

What I have on my computer

$ gsl
GSL/4.1.4 Copyright (c) 1996-2016 iMatix Corporation
syntax: gsl -<option> ... -<attr>[:<value>] ... <filename> ...
.. more detail about the command-line options omitted  

CMake (https://cmake.org/) is required if you want to compile the example C code files demonstrated by this project

Generate code

$ git clone https://github.com/vorachet/gsl_example.git
$ cd gsl_example
$ mkdir generated
$ gsl cppsystem

Once the command gsl cppsystem can be executed successfully, generated code files will be saved in the ```generated`` folder

gsl_example/generated
        ├── CMakeLists.txt
        ├── ex_serv1.cpp
        ├── ex_serv2.cpp
        ├── serv1.cpp
        ├── serv1.h
        ├── serv2.cpp
        └── serv2.h

Compile code

This step is optional. It deonstrates the creation of CMakeLists.txt and how to create executable C programs (ex_serv1, ex_serv2) from the example project.

$ cd generated
$ mkdir build
$ cd build
$ cmake ..
$ make

gsl_example/generated/build
        ├── CMakeCache.txt
        ├── CMakeFiles/ many files here
        ├── Makefile
        ├── cmake_install.cmake
        ├── ex_serv1
        └── ex_serv2

What I've learned

Advantages of GSL

• Super Fast
• Tiny program (<1Mb)
• Good Documentation
• No need to develop metamodels
• Built-in XML-based metamodel parser
• No IDE/Workbech/GUI required

GSL can be one of your productive software engineering tools. GSL has developed by Pieter. (R.I.P Pieter Hintjens - the creator of ZMQ and GSL). Pieter contributed many productive works to the software industry.

I am still looking for a solution for the following GSL application issues

• Issue-1 Merge task - How to use GSL to preserve manual code modifications across re-generations ?
• Issue-2 To parse the attr2 tag (XML element rather than XML attribute) with the following example XML model seems not possible with GSL?

<concept attr1="value1">
   <attr2>value2</attr2>
</concept>

As an MDE learner who uses more than one code generation tool, the following notes may be useful. If you are going to fix above issues and don't mind using alternative tools. Eclipse Epsilon (https://www.eclipse.org/epsilon) The Epsilon has features to satsify the issues. Issue-1 can be satisfied by https://www.eclipse.org/epsilon/doc/egl/#merge-engine. Issue-2 can be satisfied by the Eclipse Flexmi https://www.eclipse.org/epsilon/doc/flexmi/

I very much like a shell based environment and often perform MDE tasks with shell scripts. I developed mdeshell, a bash shell script based modeling environment that facilitates the definition of XML-based EMF metamodels/models and the execution of Model-2-Text transformation based on Model-Driven Engineering system implemented by the Eclipse Emfatic and the Epsilon Flexmi/EGL/EGX. Find more detail here https://github.com/vorachet/mdeshell