Learning Functional Programming in Go

main.go

Let's have a look at the contents of main.go:

func init() {   GetOptions()   if Config.LogDebugInfo {      InitLog("trace-debug-log.txt", os.Stdout, os.Stdout, os.Stderr)   } else {      InitLog("trace-log.txt", ioutil.Discard, os.Stdout, os.Stderr)   }   // use a filename in a downloads subdirectory   fileName = os.Getenv("TEST_FILENAME")   if len(fileName) == 0 {      fileName = defaultFileName  // CloudflareLogFilename(time.Now())

   }   // . . .   HandlePanic(os.Chdir(Config.ProjectRoot))}

We direct Debug statements to standard out if our  log_debug_info setting is true; otherwise, we discard them. We hardcode the name of the log file for simplicity, but we could have used a config value or a function call to dynamically generate the filename.

The last thing we ...