@extends('template')

@section('title')
    Lab 13: Fruitful Recursion
@stop

@section('content')

{{--# Lab 13: Fruitful Recursion
--}}


{{--## [Solutions](/content/labs/lab13/solutions)
--}}


## Summary
+ Part 0: Fruitful Recursion Worksheet
+ Part 1: Fruitful Recursion Warm up
{{--+ Part 2: Recursive File Traversal
--}}
+ Part 2: Fruitful Turtle Recursion 
+ Part 3: More Fruitful Turtle Recursion 


@include('/labs/_setup', ['folder' => 'lab13'])

@include('/labs/lab13/_toc')

## Big Questions {.bigqs}

- **In a fruitful recursive function, which function frames contribute to the
  value returned by the original function frame?**
  <details class="answer">
    <summary>Show Answer</summary>
    The answer here is "all of them." Although only the original function frame
    directly returns the result value, it will typically use information
    returned by other function frames to construct that value, so all of the
    function frames end up contributing to the eventual result somehow.
  </details>
- **Why is it difficult to construct an iterative function that deals with
  files in an arbitrary directory structure?**
  <details class="answer">
    <summary>Show Answer</summary>
    Because each directory can contain other directories and/or files, the
    structure of a directory is a branching structure that's similar to a tree,
    rather than a linear structure. Because of this, there is no obvious single
    dimension (or even two dimensions) along which to iterate: as you go deeper
    into the directory tree, you may find more and more files (or you might
    not). A recursive solution tends to be more natural for these kinds of
    problems: because the structure of the file tree itself is recursive:
    directories contain other directories, which may contain other directories,
    and so on.
  </details>

@stop