C-analyzer

Problem

When learning compiler fundamentals, it’s hard to see how C source code becomes tokens and how grammar rules validate structure. I wanted a practical desktop tool that makes lexing/parsing more tangible with immediate feedback.

What I built

A Tkinter desktop app that:

• Lets you paste C code in an input editor
• Produces a token stream (lexer output)
• Runs syntax parsing using a custom grammar (subset of C)
• Prints a readable, tree-like representation of recognized rules (or clear syntax errors)

Highlights

• Lexer coverage: common C keywords, identifiers, numbers, strings, operators, preprocessor directives, and more.
• Parser coverage (subset): if/else, for, while, switch/case, declarations, assignments, expressions, arrays, and function declarations.
• More robust input handling: ignores inline comments (// ...) for syntax checks and skips unsupported lines like typedef / static declarations so the analyzer can focus on the supported grammar.
• Packaging improvements: pyproject.toml, __init__.py modules, and a cleaner runnable entry (renamed screen.py → app.py).

Architecture

• analyzers/lexicon.py: lexer rules + token definitions (PLY Lex)
• analyzers/syntax.py: grammar rules + parser (PLY Yacc)
• ui/app.py: Tkinter UI + wiring (analyze lexicon / syntax / both)
• assets/: UI assets (if present)

How to run

Option A: Install as a package (recommended)

# from the repo root
pip install -e .
# or, if you have dev extras configured:
# pip install -e ".[dev]"

Run the UI:

python -m ui.app
# or
python ui/app.py

Option B: Minimal dependencies

pip install ply
python ui/app.py

Usage

1. Paste C code into the INPUT panel or select a file
2. Click
   • Analyze Lexicon to see tokens,
   • Analyze Syntax to parse supported grammar,
   • Analyze Both to run both steps.

📷 Screenshots