August 24: Pointers Part 5

[iennae]

Let's talk more about pointers! We've been working on a linked list in Go (https://github.com/osscda/lets-go-project) using pointers over the last 3 weeks (#10, #12, #14, #15 ), and we're going to continue that discussion this week.

Last week:

• Talked about different way to implement the item struct to keep track of total items in the list
• Review of tests
• Introduced slices: go built in method of list []TYPE .. list of type so list of strings with []string {}
• Updated testing
• Introduced range: range works on maps and lists.
• Talking about arrays and slices differences. Fixed sizes for arrays, program won't compile if specify out of bounds index.
• Introduced error interface
• Introduced export - captilizing it available for use for anyone else using the library. used with IndexNotFoundError struct
• Introduced fmt.Sprintf doesn't print to standard out, returns it as a string (S)
• Returning nil as a pattern to say there was no error
• Introduced profiles in VS Code, workspace specific so you can check in launch.json and figure out debugging/extensions that are needed
• Reviewed gopl problems:
• removed unreachable code
• anytime we export something (public code) we should have documented in comments because it ends up in the official go documentation. added comments for all the reported problems.
• built replace function and added testing

Agenda

• Talk about functional programming
• Call method with receiver nil
• Build Delete function
• Build Insert function

Notes

• range gives us an index and the value, use
  _ explicitly not caring about something
  idx if care about the index (or other applicable name)

• %d - holder for decimal

• documentation for the printing in use with testing -> https://pkg.go.dev/fmt?tab=doc

• Talked about differences in the struct and the meta about talking about the package itself.

• The challenge of indices and where you want

• Lots of repeating code, refactor!

• Implement getItemAtIndex

• if you are returning more than one thing (), if just one you don't need ()

• cached tests

• creating helpers for tests

checkLength(1) 
checkLength(2)

• Implement Delete
  Delete has a lot of boundary conditions. What if list has a single element, what if the list is nil.
• Pattern of putting the error handling within test for TestDelete

Rules of the Stream

• Comments and questions are always welcome in the chat.
• No question is too basic or "stupid" to ask in the chat.
• Tangents are accepted!
• No sorries needed.
• Please submit issues for new topics of interest in our repo!