As a practical person with needs for things quickly rarely do I have a need to do anything with bitwise, but that should probably change. It really isn’t that hard to use a bitfield for things instead of blowing a whole variable, but let’s be honest, that’s not the mindset of a bash coder. It is, however, of a Go coder, even one who’s just making things really quickly. Here are the basics for using them instead of variables for flags.
The long and short of it is that use |= is to turn them on and ^= is
off. All the other operators don’t seem as useful to me for most things.
But they are worth mastering eventually as well. I always learn them and
then forget them because I use them so little day to day, but flags I
definitely will.
package main
import "fmt"
const (
asleep = 1 << iota
dream
nightmare
walking
_
_
_
lucid
)
func main() {
flags := 0
flags = asleep | dream | lucid
// check em
fmt.Println(flags&(lucid|dream) == lucid|dream) // true
fmt.Println(flags&(lucid|walking) == lucid|walking) // false
fmt.Println(flags|lucid == flags) // true
fmt.Println(flags|lucid|dream == flags) // true
fmt.Println(flags|lucid|dream|asleep == flags) // true
fmt.Println(flags|lucid|dream|asleep|walking == flags) // false
fmt.Println(flags|walking == flags) // false
fmt.Printf("%010b\n", flags)
flags ^= dream
fmt.Printf("%010b\n", flags)
flags |= dream
fmt.Printf("%010b\n", flags)
/*
flags |= asleep
fmt.Printf("%b\n", flags)
flags &= asleep
fmt.Printf("%b\n", flags)
flags |= lucid
fmt.Printf("%b\n", flags)
flags >>= 3
fmt.Printf("%b\n", flags)
flags <<= 3
fmt.Printf("%b\n", flags)
*/
}
Go Bitwise Operators
https://www.w3schools.com/go/go_bitwise_operators.php
#golang #tips #bitwise #coding