T-Linter for Visual Studio Code

Intelligent syntax highlighting and validation for Python template strings (PEP 750) with embedded language support.

Features

🎨 Smart Syntax Highlighting - Automatic detection and highlighting of embedded languages
🔍 Type-based Detection - Understands Annotated[Template, "language"] annotations
💡 IntelliSense Support - Code completion within template strings
🚀 Fast & Lightweight - Built with Rust for optimal performance
🔧 Highly Configurable - Customize behavior to match your workflow

Supported Languages

HTML
SQL
JavaScript
CSS
JSON

Requirements

Visual Studio Code 1.74.0 or higher
Python 3.9+ (PEP 750 template strings require Python 3.14+)
t-linter language server (installed automatically or manually)

Installation

Option 1: Install from VSCode Marketplace

Open VSCode
Go to Extensions (Ctrl+Shift+X)
Search for "t-linter"
Click Install

Option 2: Install t-linter manually

pip install t-linter

Usage

Basic Example

from typing import Annotated
from string.templatelib import Template

# Automatic HTML syntax highlighting
def render_page(content: Annotated[Template, "html"]) -> str:
    return content.render()

page = t"""
<!DOCTYPE html>
<html>
    <body>
        <h1>{title}</h1>
        <p>{content}</p>
    </body>
</html>
"""

# SQL highlighting
query: Annotated[Template, "sql"] = t"SELECT * FROM users WHERE id = {user_id}"

Type Alias Support (Python 3.12+)

# Define reusable type aliases
type html = Annotated[Template, "html"]
type sql = Annotated[Template, "sql"]

# Use with automatic language detection
content: html = t"<div>{message}</div>"
db_query: sql = t"UPDATE users SET name = {name} WHERE id = {id}"

Function Parameter Inference

def execute_query(query: sql) -> list:
    return db.execute(query)

# Language inferred from function parameter type
execute_query(t"SELECT * FROM products WHERE price < {max_price}")

Configuration

This extension contributes the following settings:

t-linter.enabled: Enable/disable the t-linter extension
t-linter.serverPath: Path to t-linter executable (leave empty for automatic detection)
t-linter.highlightUntyped: Highlight template strings without type annotations (default: true)
t-linter.enableTypeChecking: Enable integration with Python type checkers for cross-module resolution (default: true)
t-linter.trace.server: Trace communication between VSCode and the language server (off/messages/verbose)

Commands

This extension contributes the following commands:

T-Linter: Restart Server: Restart the t-linter language server
T-Linter: Show Template String Statistics: Display statistics about template strings in the current file

Troubleshooting

Language server not found

If you see "t-linter binary not found", install it using:

pip install t-linter

No syntax highlighting

Ensure Python semantic highlighting is enabled
Check that your template strings use the t"..." syntax
Verify type annotations are correctly formatted

Performance issues

Disable t-linter.enableTypeChecking if you don't need cross-module type resolution
Set t-linter.trace.server to "off" in production

Known Issues

Cross-module type resolution requires a Python type checker (Pyright/Pylsp) to be installed
Limited to single-file analysis scope in the current version

Contributing

Found a bug or have a feature request? Please open an issue on our GitHub repository.

License

MIT - See LICENSE for details.

T-Linter - Python Template Strings Highlighter & Linter

Koudai Aono (koxudaxi)