LP Linter

LP Linter

LP Linter is a static analysis tool for LP language, similar to pylint, flake8, mypy for Python.

🚀 Basic Usage

# Check LP file
python tools/lp_linter.py myfile.lp

# Or use wrapper script
./tools/lp-check myfile.lp

Options

Flag	Description
--strict	Enable strict mode (check style)
--json	Output results as JSON
--quiet	Show only errors (no warnings)
--no-color	Disable colored output

Examples

# Strict mode
python tools/lp_linter.py myfile.lp --strict

# JSON output
python tools/lp_linter.py myfile.lp --json

# Only errors
python tools/lp_linter.py myfile.lp --quiet

🔍 Errors Detected

Errors (E001-E009)

Code	Description	Example
E001	Unknown module	import unknown_module
E002	Unknown type	x: foobar = 1
E003	Missing type annotation	def f(x): pass
E004	Using None instead of null	x = None
E005	Type ptr not allowed	x: ptr = ...
E006	Missing : after keyword	if x > 5
E007	Common typo	printl("hi")
E008	Missing dsa.flush()	When using dsa.write_*
E009	DSA output without flush	When using dsa module

Warnings (W001-W002)

Code	Description
W001	Assignment in if (did you mean ==?)
W002	Function defined but never called

Style (S001-S003) - only with --strict

Code	Description
S001	Line too long (> 100 chars)
S002	Trailing whitespace
S003	Multiple spaces around operator

📝 Output Examples

Normal output

🔍 Found 3 issue(s): 2 error(s), 1 warning(s), 0 style

❌ [E004] Line 5:7: Use 'null' instead of 'None' in LP
    💡 Suggestion: Replace 'None' with 'null'

❌ [E008] Line 10:1: dsa module requires dsa.flush() before program exit
    💡 Suggestion: Add 'dsa.flush()' at the end of your program

⚠️ [W002] Line 3:1: Function 'main/solve' defined but never called
    💡 Suggestion: Add 'main()' or 'solve()' at the end of the file

JSON output

[
  {
    "line": 5,
    "col": 7,
    "code": "E004",
    "severity": "ERROR",
    "message": "Use 'null' instead of 'None' in LP",
    "suggestion": "Replace 'None' with 'null'"
  }
]

✅ Correct Code

import dsa

def solve() -> int:
    n: int = dsa.read_int()
    dsa.write_int_ln(n * 2)
    dsa.flush()  # ← Correct: has flush()
    return 0

solve()  # ← Correct: calls function

❌ Incorrect Code

import dsa

def solve() -> int:
    n: int = dsa.read_int()
    arr: list = None  # ❌ E004: Using None
    dsa.write_int_ln(n * 2)
    # ❌ E008: Missing dsa.flush()
    return 0

# ❌ W002: Not calling solve()

🔧 Editor Integration

VS Code

Add to settings.json:

{
    "files.associations": {
        "*.lp": "lp"
    },
    "terminal.integrated.commandsToRun": [
        "python tools/lp_linter.py ${file}"
    ]
}

Vim/Neovim

" Add to .vimrc
autocmd BufWritePost *.lp :!python tools/lp_linter.py %

Pre-commit Hook

Create file .git/hooks/pre-commit:

#!/bin/bash
for file in $(git diff --cached --name-only | grep '\.lp$'); do
    python tools/lp_linter.py "$file" --quiet
    if [ $? -ne 0 ]; then
        echo "Linter found errors in $file"
        exit 1
    fi
done

🎯 Best Practices

1. Always run linter before compiling

   python tools/lp_linter.py myfile.lp && lp myfile.lp

2. Use --strict for production code

   python tools/lp_linter.py myfile.lp --strict

3. Integrate into CI/CD

   # GitHub Actions
   - name: Lint LP files
     run: python tools/lp_linter.py src/*.lp --strict

📊 Comparison with Python

Python	LP
pylint file.py	python tools/lp_linter.py file.lp
flake8 file.py	python tools/lp_linter.py file.lp --strict
mypy file.py	Type checking built into linter
black file.py	No formatter yet

🔄 Recommended Workflow

# 1. Write code
vim solution.lp

# 2. Run linter
python tools/lp_linter.py solution.lp --strict

# 3. Fix errors

# 4. Compile
lp solution.lp -c solution

# 5. Test
./solution < input.txt

# 6. Commit
git add solution.lp
git commit -m "Add solution"