My Answers to the Official Go Tour

Found at: https://go.dev/tour/ My first time learning and using Go

Problem Descriptions

Exercise Loops and Functions

Implement a square root function using Newton's method. Function returns when the error is less than or equal to epsilon or maxitr number of max iterations are reached.

Exercise Slices

Pic should return a slice of length dy, each element of which is a slice of dx 8-bit unsigned integers. When you run the program, it output base 64 representing your picture, interpreting the integers as grayscale values. Otherwise if you're using the Go Tour page it will display your picture in bluescale. The choice of image generation fn is free.

Exercise Maps

Implement WordCount using stirngs.Fields. It returns a map of the counts of each "word" (space separated) in the string s. Uses the golang tour wc.Test function to run a test suite against the provided function and prints success or failure.

Exercise Fibonacci Closure

The fibonacci function returns a function that returns successive fibonacci numbers (0, 1, 1, 2, 3, 5, ...) using a closure.

Exercise Stringers

Implement fmt.Stringer on the IPAddr type to print the address as a dotted quad. IPAddr{1, 2, 3, 4} should print as "1.2.3.4".

Exercise Errors

Copy the Sqrt function from the earlier "Loops and Functions" exercise. It is modified to return an error value when given a negative number. Implements the Error() function.

Exercise Readers

Implemented a Reader type that emits an infinite stream of ASCII "A".

Exercise rot13Reader

Implement the io.Reader interface on the rot13Reader type by implementing the Read method. The rot13Reader implements io.Reader and reads from an io.Reader, modifying the stream by applying the rot13 substitution cipher to all alphabetical characters.

Exercise Images

Rewrite the earlier picture generator in the "Slices" exercise to implement image.Image instead of a slice. A custom Image type is defined and the ColorModel, Bounds and At functions are implemented to be able to call pic.ShowImage.

Exercise Equivalent Binary Trees

Using the golang tour tree package, implement and test the Walk function. Implement the Same function and test it.

Exercise Web Crawler

Used Go's concurrency features to parallelise a web crawler. Modified the Crawl function to fetch URLs in parallel without fetching the same URL twice. Crawl uses fetcher to recursively crawl pages starting with url, to a maximum of depth.