Go for essential to Advanced

Logging & Error Handling

Logging or others

• log.Print: General purpose logging of information. Doesn't terminate.
• log.Printf: Same as Print but allows formatting.
• log.Fatal: Logs and then calls os.Exit(1) to terminate. For unrecoverable errors.
• log.Panic: Logs and panics. For critical unrecoverable errors.
• log.Panicf: Same as Panic but allows formatting.
• fmt.Errorf: Returns an error object. Doesn't log or terminate. Used to return errors.
• errors.New: Same as Errorf but without formatting.

Testing

• t.Error: Logs an error but continues test execution.
• t.Errorf: Logs a formatted error but continues.
• t.Fatal: Logs and marks the test as failed. Terminates the test.
• t.Fatalf: Same as Fatal but with formatting.

Summary

• Print | Printf for general logging
• Fatal for unrecoverable errors that need to terminate
• Panic for critical errors that shouldn't continue
• Errorf to create error objects to return
• t.Error | t.Errorf to log errors but continue tests
• t.Fatal | t.Fatalf to log and fail fast during tests

Build Options & Compiler Directives

Build Options

• escape analysis

go build -gcflags=-m main.go

• Run benchmark testing

go test -bench .

• Detect data race

go run -race .
go test -race ./...

Compiler Directives

• //go:linkname, only useable in condition of package unsafe

//go:linkname localname [importpath.name]

• //go:noescape, prevent variables escape to heap
• //go:nosplit, disable stack splitting
• //go:inline

Useful third-party packages

strings

• NewReplacer

  used to replace multiple values, here is an example:

  // Even index for argument be replaced, odd index for what you want to replace with.
  replacer := strings.NewReplacer(":", "", "^", "", "*", "")
  str := "Hi:, I'm *Tinaaa, Help.... m^e..:)"
  str = replacer.Replace(str)
  
  fmt.Println(str)    // Hi, I'm Tinaaa, Help.... me..)
  

Resources

• The Go Programming Language Specification 1.23