Compiler Starter Project

• Compiler Starter Project
  • Dependencies
  • Getting Started
    • VSCode setup
    • Running Debug
    • Running Task
    • Installing dependency
  • Code Explain
    • components/lexica.py
    • components/parsers.py
      • MyParser class
      • ASTParser class
    • components/memory.py
    • main.py and components/main.ui
  • Design a GUI

This is the starter project for the Programming Language and Compiler course @ AIT. Since 2024, we use Python.

Dependencies

• Python version 3.9.18
• uv for managing project
• PySide6 for GUI development

Getting Started

As of January 2026, this project drop the support for Docker. We figure that it only make thing more complicated and decided to use uv and vscode to control the environment.

To use this repository, follow below steps.

1. (Optional) Click Use this template on the top right of this page to clone this to your repository.
2. Clone the project to your local machine.
3. Go to project folder and run uv sync.

VSCode setup

The repository has a file .vscode/extensions.json which will automatically install extension for you. In case that this mechanism fails, here are the list of required extension.

• ms-python.python
• ms-python.debugpy

Running Debug

The repository has support for running the code in debug mode. Check the .vscode/launch.json.

By default, you can run [example] Python Debugger option which launch the src/example module. We sort-of giving an example of how to create mulitple entrypoints by providing the second option [project] Python Debugger which is not ready to use until you create a module src/project.

Running Task

To execute the module, we provide Tasks under the .vscode/tasks.json. There are three tasks initially.

1. start app: For launching the example project.
2. start designer: For launching PySide6-designer app.
3. compile designer: For compiling the ui file generated from the PySide6-designer.

To run them, you can do it from the command palette Ctrl/Cmd + Shift + P. Choose Tasks: Run Task, and choose the option will appear.

Installing dependency

Most of the requirement should be sorted out with uv sync. However, for no obvious reason right now, PySide6-designer would not run within the uv context. You will need to install the PySide6 library again using pip install.

pip install pyside6

When you are done with this project, you can remove them with this

pip uninstall pyside6 PySide6_Addons PySide6_Essentials

Code Explain

Inside src/example/ folder is all the code developed.

compiler-starter-project/
  |- components/
      |- ast/
          |- statement.py
      |- lexica.py
      |- main.ui
      |- memory.py
      |- parsers.py
  |- main.py

Since the project is done just to showcase libraries and techniques, here we divided it into subsections to explain the code.

components/lexica.py

This file showcases the Lexica analyzer component. It has a MyLexer class that extends sly.Lexer. It will translate a code/string into token stream/generator that feeds to a Parser. This file has a main just for testing the class.

components/parsers.py

There are two parsers. (1) MyParser and (2) ASTParser.

MyParser class

This class is what I call immediate evaluation which each of the semantics, once reduced, evaluates/calculates right away. This type of parser is fine for calculator projects or simple parsing. This parser also implements Memory and Variable assignment.

ASTParser class

This is a more complex but flexible way of parsing. AST (Abstract Syntax Trees) is actually a parse tree. This will allow you to control when to run a subsection of code like if-else statement. You can see that the semantic part is only creating an object inside components.ast. All the logic (in this case, addition and subtraction) is in the AST object. The Parser is there is create a parse tree that once ready will execute .run(). I only add the essentials to demonstrate this technique.

components/memory.py

This contains Memory class which is a singleton. Inside is just a simple dictionary where variable_name is a key and {'value':value,'data_type':<type>} as a value. Whether this solution is appropriate or not is your judgment.

main.py and components/main.ui

Finally, the main.py is the main file to run the entire project. It will render a GUI from components/main.ui that was designed from PyQt6. This shows how to bind a function with a button and how to display the result back to the GUI.

Design a GUI

We use PySide6 and pyside6-designer for GUI development. You can start to learn this tool from

• Official Document
• 3rd party Tutorial

To launch the designer, use Running Task