How do you implement error recovery?

Question

Accepted Answer

**Error recovery** — handle errors gracefully.

**Pattern matching:**
```rust
fn read_config() -> Result<Config, ConfigError> {
    match std::fs::read_to_string("config.toml") {
        Ok(content) => toml::from_str(&content).map_err(ConfigError::Parse),
        Err(e) => Err(ConfigError::Io(e)),
    }
}
```

**unwrap_or:**
```rust
let config = read_config().unwrap_or_default();
```

**map_err:**
```rust
let config = read_config()
    .map_err(|e| format!("Failed: {}", e))?;
```

**and_then:**
```rust
let value = parse_number("42")
    .and_then(|n| divide(n, 2));
```

**Key:** Use Result methods for recovery.

Rust: How do you implement error recovery?