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pythonc++parsingcode-generationply

Python generating different files from one file

What I am trying to do is to use Python to parse script bob.ps and output bob.py and bob.cpp depending on user input.

lets say we had bob.ps which is python-like simple language

#comment
use ShowBase
# Load the environment model.
environ = loadModel 'cube'
# Reparent the model to render.
render environ
run

User would need to run python script with commands like : $ python main.py -py -c++ and it would result generating following python and c++ scripts:

from direct.showbase.ShowBase import ShowBase
class MyApp(ShowBase):

    def __init__(self):
       ShowBase.__init__(self)
       # Load the environment model.
          self.environ = self.loader.loadModel("models/environment")
       # Reparent the model to render.
       self.environ.reparentTo(self.render)
app = MyApp()
app.run()

and c++

#include "pandaFramework.h"
#include "pandaSystem.h"

int main(int argc, char *argv[]) {
      // Load the window and set its title.
   PandaFramework framework;
   framework.open_framework(argc, argv);
   framework.set_window_title("My Panda3D Window");
   WindowFramework *window = framework.open_window();
      // Load the environment model.
   NodePath environ = window->load_model(framework.get_models(), "models/environment");
      // Reparent the model to render.
   environ.reparent_to(window->get_render());
      // Run the engine.
   framework.main_loop();
      // Shut down the engine when done.
   framework.close_framework();
   return (0);
}

The problem

I spent some time browsing the internet for answers. What I found out is that I need to parse bob.ps and use lexer. I tried to mess little bit with PLY-3.4 and it doesn't exactly do what I want to accomplish. I don't need/want to execute code while parsing instead my intention is only to generate equivalent python/c++ code.

What would be best approach to this problem, is there any module/book/article/tutorial on this specific subject? I really hit the wall and don't know where to look. Any help is highly appreciated.

Solution

  • What you want to do here is a bit like a compiler. You want to compile "ps" to python or cpp.

    Standard tools for that are lex and yacc and there is plenty of litterature on that everywhere.