go_goutils/types/bitmasks.go
2021-07-27 22:30:10 -04:00

65 lines
902 B
Go

package types
/*
See https://yourbasic.org/golang/bitmask-flag-set-clear/ for more information.
To use this, set constants like thus:
const (
OPT1 types.MaskBit = 1 << iota
OPT2
OPT3
// ...
)
type Object struct {
Opts BitMask
}
o := Object{
BitMask: uint8(0)
}
o.AddFlag(OPT1)
o.AddFlag(OPT3)
This would return true:
o.HasFlag(OPT1)
As would this:
o.HasFlag(OPT3)
But this would return false:
o.HasFlag(OPT2)
*/
type BitMask interface {
HasFlag(bit MaskBit) bool
AddFlag(bit MaskBit)
ClearFlag(bit MaskBit)
ToggleFlag(bit MaskBit)
}
// BitMasks
type MaskBit uint8
func (f MaskBit) HasFlag(flag MaskBit) (r bool) {
if f&flag != 0 {
r = true
}
return
}
func (f *MaskBit) AddFlag(flag MaskBit) {
*f |= flag
return
}
func (f *MaskBit) ClearFlag(flag MaskBit) {
*f &= flag
return
}
func (f *MaskBit) ToggleFlag(flag MaskBit) {
*f ^= flag
return
}