reduce complexity for readability

Prioritize code readability by reducing complexity through better organization and clearer patterns. Use early returns to avoid deep nesting, extract methods to break down large functions, and choose appropriate data structures over generic ones.

Key practices:

• Use early returns to reduce nesting levels instead of deeply nested if-else chains
• Extract methods when functions become large or handle multiple responsibilities
• Replace tuples with named structs when multiple values need to be distinguished
• Prefer idiomatic patterns like match expressions and iterator methods over manual loops
• Remove unnecessary abstractions like builder patterns when they don’t add value

Example of improving nested code:

// Instead of deep nesting:
if ancestor.is::<Document>() {
    true
} else if ancestor.is::<Element>() {
    let ancestor = ancestor.downcast::<Element>().unwrap();
    // ... complex logic
} else {
    false
}

// Use early returns:
if ancestor.is::<Document>() {
    return true;
}
let Some(ancestor) = ancestor.downcast::<Element>() else {
    return false;
};
// ... simplified logic

This approach makes code easier to follow, test, and maintain by reducing cognitive load and making the control flow more explicit.