2025-03-13 Meeting notes

GoLang Review

• defer: https://go.dev/tour/flowcontrol/12

  • in lower level languages, failing to close a file can result in memory leaks

  • defer closes the file even on error

  • Extra info: Defer, Panic, and Recover - The Go Programming Language

GoLang Continued

• Errors

  • GoLang is very explicit in error handling

  • If a function you call has the possibility to return an error, you must check for it, lest the compiler be mad

• Pointers: https://go.dev/tour/moretypes/1

  • Type safe so can’t do

    • Pointer arithmatic

    • Explicit typing prevents incorrect conversions

• struct

  • No inheritance but there is composition (include fields from one struct in another)

  • Can declare with values in order of the fields or explicity

    • Vertex{1, 2} and Vertex{X:1, Y:2} are the same

    • Undeclared values default to 0 for numeric and nil for others

  • Access a struct when it is a pointer with V.X instead of V->X

• Arrays

  • Fixed size, low level

  • Is an array when given a size. ex. var x [2]int

• Slices

  • Resizable

  • Is a slice when not given a size. ex. var x []int

  • Resizing can be done with s = s[x:y] syntax where x and y represent the start and end of the resizing

    • Elements cut off from the end can be recovered by enlarging the array

    • Cutting off elements from the front discards them

  • make: create an underlying array

    • can set capacity and length (number to initialize)

    • slice of a slice is a reference to a reference which means its referring to the same base array

    • indexing beyond the length is allowed as long as it is within the capacity

  • append

    • adds values, increasing capacity when necessary

      • doubles the capacity when needed

    • does not modify the slice, creates a new one that must be assigned

      • s = append(s, 0)

Questions

• What do we need to know to get started with ChromeDP

  • What we’ve covered so far should be sufficient

  • Maybe look into methods and interfaces as well. Try to get up to but not through generics on A Tour of Go

  • Resources

    • chromedp package - github.com/chromedp/chromedp - Go Packages

    • GitHub - chromedp/examples: chromedp code examples.