Struct ReferenceTreeBuilder 

pub struct ReferenceTreeBuilder;

Builder for constructing reference trees from search results.

Rust Book Reference

Chapter 4: Understanding Ownership https://doc.rust-lang.org/book/ch04-00-understanding-ownership.html

This builder demonstrates how to work with borrowed data to construct owned data structures efficiently.

Implementations

impl ReferenceTreeBuilder

pub fn build(result: &SearchResult) -> ReferenceTree

Build a reference tree from search results.

Creates a hierarchical tree structure:

• Root: search query text
  • Translation: translation file entry
    • KeyPath: full translation key
      • CodeRef: code reference using the key

Rust Book Reference

Chapter 4.2: References and Borrowing https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html

Educational Notes - Borrowing with &SearchResult

This method signature demonstrates immutable borrowing:

pub fn build(result: &SearchResult) -> ReferenceTree
//                   ^
//                   Borrows result, doesn't take ownership

Why borrow instead of taking ownership?

1. Caller keeps ownership:

   let result = search_translations("add new")?;
   let tree = ReferenceTreeBuilder::build(&result);  // Borrow
   // result is still usable here!
   println!("Found {} entries", result.translation_entries.len());

2. No unnecessary cloning:

   • If we took ownership: build(result: SearchResult)
   • Caller would need: build(result.clone()) - expensive!
   • With borrowing: build(&result) - zero cost!

3. Rust’s borrowing rules ensure safety:

   • The reference &result is valid for the entire function
   • We can read all fields: result.query, result.translation_entries
   • We cannot modify the data (immutable borrow)
   • The original data cannot be moved while borrowed

Inside the function:

• We borrow fields: &result.translation_entries
• We clone when we need ownership: result.query.clone()
• We iterate with .iter() to borrow elements: for entry in &result.translation_entries

Key Insight: Borrowing is Rust’s way of saying “I just need to look at this data temporarily, I don’t need to own it.”