Regex Pattern Generator

## ROLE
You are a regex expert who creates precise, efficient patterns.

## CONTEXT
I need a regex pattern for:

**Pattern Requirements:**
- Use Case: [USE_CASE]
- Input Examples (should match): [MATCH_EXAMPLES]
- Input Examples (should NOT match): [NO_MATCH_EXAMPLES]
- Language/Engine: [REGEX_ENGINE]
- Case Sensitivity: [CASE_SENSITIVE]

## TASK
Generate and explain regex pattern:

### 1. THE PATTERN
```regex
[REGEX_PATTERN]
```

### 2. PATTERN BREAKDOWN
| Part | Pattern | Explanation |
|------|---------|-------------|
| 1 | [part] | [what it matches] |
| 2 | [part] | [what it matches] |
| ... | ... | ... |

### 3. VISUAL EXPLANATION
```
[REGEX_PATTERN]
│  │  │  │
│  │  │  └─ [explanation]
│  │  └──── [explanation]
│  └─────── [explanation]
└────────── [explanation]
```

### 4. TEST CASES
| Input | Expected | Match? |
|-------|----------|--------|
| [input1] | [expected1] | ✓ |
| [input2] | [expected2] | ✓ |
| [input3] | [expected3] | ✗ |

### 5. CODE EXAMPLES
```javascript
// JavaScript
const pattern = /[PATTERN]/g;
const matches = text.match(pattern);
```

```python
# Python
import re
pattern = r"[PATTERN]"
matches = re.findall(pattern, text)
```

### 6. CAPTURE GROUPS (if applicable)
| Group | Name | Captures |
|-------|------|----------|
| $1 | [name] | [what it captures] |
| $2 | [name] | [what it captures] |

### 7. EDGE CASES HANDLED
- [Edge case 1]: [how handled]
- [Edge case 2]: [how handled]

### 8. PERFORMANCE NOTES
- Avoid backtracking with [technique]
- Use possessive quantifiers if available
- Consider [optimization]

## RULES
- Make patterns as specific as possible
- Avoid catastrophic backtracking
- Use non-capturing groups when possible
- Consider unicode if needed
- Test with edge cases