---
name: functions
description: List every function, method and class in a file and explain each one in plain words (what it does, inputs → output, who calls it), plus how they connect; or explain one function step by step. Use when the user asks "what's in this file", "what does this file do", "explain these functions", "walk me through this code", or opens an unfamiliar file they vibe coded. Invoke with `<file>` for a tour or `<file> <function>` for a deep dive.
---

# Code Tour: what lives in this file?

Vibe coders end up with files full of functions they never read. A tour gives them a map:
every function, what it is for, and how the pieces call each other.

## Steps
1. **Read the whole file** (don't guess from the name). For big files (500+ lines), read it in parts.
2. **Find every definition**: functions, methods, classes, components, hooks, handlers, exported constants that hold logic.
   Record the **line number** for each so the user can jump to it.
3. **Work out the connections**: which function calls which, what is exported/used by other files, what is the entry point.
4. **Spot notable algorithms/patterns** while reading (skill `algorithms`) and mark them with 🧮.

No file given? Use the file most recently edited or discussed in the conversation and say which one you picked.

## Output format
**📄 `<file>` in one sentence:** what this file is responsible for, like a job title.

| # | Function | Line | What it does (plain words) | In → Out |
|---|---|---|---|---|
| 1 | `loadUser(id)` | 12 | Fetches one user from the database | user id → user object or `null` |

- Group methods under their class (`ClassName.method`), and list classes first.
- "What it does" is **one sentence**, no jargon. Mark helpers nobody calls with `⚠️ unused?`.
- Add 🧮 next to a function that contains a notable algorithm (details come from `$algorithms`).

**🔗 How they connect:** an arrow diagram of the main flow, at most ~6 boxes:
```
handleSubmit() → validateForm() → saveOrder() → showToast()
```

**🚪 Start reading here:** the one function a beginner should read first, and why (1 line).

## Principles
- Be exact: names and line numbers must match the file. Never invent a function.
- Prefer the *purpose* ("decides whether the user may log in") over restating code ("returns a boolean").
- More than ~25 functions → show the 15 most important ones and say how many were left out.
- With ADHD mode on: show only the table's first 5 rows, then ask whether to continue.

## One function in depth (a file and a function name were given)
1. **What it's for** (1 sentence).
2. **Step by step:** each block of the function in 1-2 plain lines, citing line numbers.
3. **In → Out:** parameters, return value, and side effects (writes to a file, calls an API, changes state...).
4. **Who calls it / what it calls.**
5. **🧮 Algorithm or pattern** inside, if any (skill `algorithms`).
6. **⚠️ Edge cases** it does or doesn't handle (empty input, `null`, errors).