= Exercise 5.1 // Refs: :url-base: https://github.com/fenegroni/TGPL-exercise-solutions :workflow: workflows/Exercise 5.1 :action: actions/workflows/ch5ex1.yml :url-workflow: {url-base}/{workflow} :url-action: {url-base}/{action} :badge-exercise: image:{url-workflow}/badge.svg?branch=main[link={url-action}]

{badge-exercise}

Change the findlinks program to traverse the n.FirstChild linked list using recursive calls to Visit instead of a loop.

== Test

The implementation validates that given an HTML document with zero, one, or more links, they are all still returned by the new recursive implementation, as they were returned by the original implementation.

=== Original implementation

The book's implementation of Visit uses a for-loop to visit c.NextSibling within the sub-node:

[source,go]

for c := n.FirstChild; c != nil; c = c.NextSibling { links = Visit(links, c) }

=== Fully-recursive implementation

The solution to the exercise uses no such for loop.

Visit now recursively calls itself with the correct parameters:

[source,go]

return Visit(Visit(links, n.FirstChild), n.NextSibling)

== Example

Given this example HTML document as input:

[source,html]

the Example function's Output is:

[source,go]

// Output: // link1 // link2