Crawl uses fetcher to recursively crawl pages starting with url, to a maximum of depth.

image 256x256.

Same determines whether the trees t1 and t2 contain the same values.

exercise Sqrt with loop.

Walk walks the tree t sending all values from the tree to the channel ch.

const cannot be declared and assigned using ":=" constructor.

Errors.

example of implementing Stringer interface (method String()).

SafeCounter is safe to use concurrently.

interface is a type that can be anything that implements methods determind in the interfaces set, those functions have to be known during compilation (at least thats what i assume) otherwise it'll not compile.