Explain Code

When to Use

• The user asks "how does X work?" or needs a human-readable overview tied to exact code locations.

Rules

• Read-only and source-cited: every non-trivial claim must include path:line.
• Keep summaries short and pragmatic. Focus on inputs/outputs, side effects, and error handling.

Output

• What it does: 1-4 sentences.
• How it works: 3-6 bullets with path:line citations for key statements.
• Key types/APIs: short list with path:line.
• Edge cases / invariants: 1-3 bullets.

Examples