textlint-rule-punctuation-end-of-equation

A textlint rule to enforce punctuation at the end of LaTeX math environments in academic writing.

Installation

From npm (when published)

npm install textlint-rule-punctuation-end-of-equation

Local development/usage

1. Clone and build the rule:

   git clone <this-repo>
   cd period-endof-equation
   pnpm install
   pnpm run build

2. Install textlint globally:

   npm install -g textlint

3. Link the rule locally:

   # In the rule directory
   npm link
      
   # In your document directory
   npm link textlint-rule-punctuation-end-of-equation

4. Create a .textlintrc file in your document directory:

   {
     "plugins": ["@textlint/markdown"],
     "rules": {
       "punctuation-end-of-equation": true
     }
   }

5. Run textlint on your documents:

   # Check a single file
   textlint your-document.md
      
   # Check and auto-fix
   textlint --fix your-document.md
      
   # Check all markdown files
   textlint "**/*.md"

Configuration Options

You can customize which math environments and punctuation marks to check:

{
  "rules": {
    "punctuation-end-of-equation": {
      "allowedMathEnvironments": ["equation", "align", "gather", "multline"],
      "allowedPunctuation": [".", ",", ";", "!", "?"]
    }
  }
}

Options

• allowedMathEnvironments (default: ["equation", "align", "gather", "multline", "split", "eqnarray"]): LaTeX math environments to check
• allowedPunctuation (default: [".", ",", ";", "!", "?"]): Punctuation marks considered valid at the end of equations

Alternative: Direct usage without global installation

If you prefer not to install textlint globally:

1. Install textlint locally in your document project:

   # In your document directory
   npm init -y
   npm install textlint @textlint/textlint-plugin-markdown
   npm link textlint-rule-punctuation-end-of-equation

2. Add scripts to your package.json:

   {
     "scripts": {
       "lint": "textlint *.md",
       "lint:fix": "textlint --fix *.md"
     }
   }

3. Run with npm:

   npm run lint
   npm run lint:fix

What it checks

This rule enforces punctuation at the end of LaTeX math environments:

• Display math: $$...$$
• Display math: \[...\]
• Environment-based math: \begin{equation}...\end{equation}, \begin{align}...\end{align}, etc.

Valid examples

This is correct: $$x = y + z.$$

With comma: $$f(x) = x^2,$$

With semicolon: \[a = b + c;\]

\begin{equation}
E = mc^2.
\end{equation}

\begin{align}
x &= y + z, \\
a &= b + c.
\end{align}

Invalid examples

This is wrong: $$x = y + z$$

Another wrong example: \[a = b + c\]

\begin{equation}
E = mc^2
\end{equation}

Development

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Lint
npm run lint

License

MIT