Cursor Tab Completion Mastery

How Tab Completion Works

The Completion Flow

1. You type code
2. Cursor analyzes context (open files, imports, patterns)
3. AI generates suggestion (ghost text)
4. Ghost text appears in gray
5. Press Tab to accept, Esc to reject

Visual Indicators

def calculate_total(items):
    │                          ← Cursor here
    return sum(item.price for item in items)  ← Ghost text (gray)

Accepting Completions

Full Acceptance

• Tab: Accept entire suggestion
• Cursor moves to end of inserted text

Partial Acceptance

• Ctrl+Right: Accept next word
• Cmd+Right (Mac): Accept to end of line
• Hold Tab: Accept character by character

Rejecting Completions

• Esc: Dismiss current suggestion
• Continue typing: Suggestion updates
• Move cursor: Suggestion dismissed

Cycling Through Suggestions

Multiple Suggestions

• Alt+]: Next suggestion
• Alt+[: Previous suggestion
• Cycle through alternatives

Triggering Suggestions

• Ctrl+Space: Force suggestion
• Useful when suggestion doesn't appear automatically

Context Awareness

What Influences Completions

1. Current file content
2. Open tabs
3. Import statements
4. Recent edits
5. Project structure
6. .cursorrules file
7. Comments and docstrings

Writing Better Triggering Code

# Good - descriptive comment triggers better completion
# Calculate total price including tax and discounts
def calculate_final_price(items, tax_rate, discount):
    │ ← AI understands intent from comment

# Good - type hints guide completion
def process_users(users: list[User]) -> dict[str, int]:
    │ ← AI knows input/output types

Completion Settings

Adjusting Completion Behavior

// settings.json
{
  // Delay before showing suggestions (ms)
  "cursor.completion.delay": 100,

  // Enable/disable completions
  "cursor.completion.enabled": true,

  // Completion length preference
  "cursor.completion.preferLonger": true,

  // Inline suggestions
  "editor.inlineSuggest.enabled": true
}

Model for Completions

Settings > Cursor > Completion Model

Options:
- GPT-4 (higher quality, slower)
- GPT-3.5-turbo (faster, lighter)
- Cursor-small (optimized for speed)

Completion Patterns

Function Bodies

def fibonacci(n):
    # Tab completes the entire function
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

Repetitive Code

// If you've defined similar patterns, AI continues them
const handleNameChange = (e) => setName(e.target.value);
const handleEmailChange = │ // Completes similarly

Test Generation

def test_calculate_total():
    # AI suggests test cases based on function signature
    items = [Item(price=10), Item(price=20)]
    result = calculate_total(items)
    assert result == 30

Documentation

def complex_function(data: dict, options: Options) -> Result:
    """
    │ ← AI completes docstring with params, returns, examples
    """

Troubleshooting Completions

Completions Not Appearing

1. Check if enabled: Settings > Cursor > Completion
2. Check rate limits: Status bar shows remaining
3. Check network: AI needs connectivity
4. Restart Cursor if stuck

Poor Quality Suggestions

1. Add more context (comments, types)
2. Check .cursorrules configuration
3. Try different completion model
4. Let codebase indexing complete

Completions Too Aggressive

// Reduce completion frequency
{
  "cursor.completion.delay": 500,
  "editor.quickSuggestions": {
    "other": false,
    "comments": false,
    "strings": false
  }
}

Best Practices

Guide the AI

# Be explicit about what you want
# TODO: implement binary search on sorted array
def binary_search(arr, target):
    │ ← Better completion with clear intent

Use Type Hints

def process(data: pd.DataFrame) -> pd.DataFrame:
    │ ← AI knows pandas methods to suggest

Maintain Code Style

// If your codebase uses certain patterns,
// AI learns and continues them
const Component = ({ props }) => {
  │ ← Matches your existing component patterns
};

Review Before Accepting

Always review ghost text:
- Check logic correctness
- Verify variable names
- Ensure style consistency
- Watch for security issues