consul/vendor/github.com/mitchellh/pointerstructure/sort.go

43 lines
1.1 KiB
Go

package pointerstructure
import (
"sort"
)
// Sort does an in-place sort of the pointers so that they are in order
// of least specific to most specific alphabetized. For example:
// "/foo", "/foo/0", "/qux"
//
// This ordering is ideal for applying the changes in a way that ensures
// that parents are set first.
func Sort(p []*Pointer) { sort.Sort(PointerSlice(p)) }
// PointerSlice is a slice of pointers that adheres to sort.Interface
type PointerSlice []*Pointer
func (p PointerSlice) Len() int { return len(p) }
func (p PointerSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p PointerSlice) Less(i, j int) bool {
// Equal number of parts, do a string compare per part
for idx, ival := range p[i].Parts {
// If we're passed the length of p[j] parts, then we're done
if idx >= len(p[j].Parts) {
break
}
// Compare the values if they're not equal
jval := p[j].Parts[idx]
if ival != jval {
return ival < jval
}
}
// Equal prefix, take the shorter
if len(p[i].Parts) != len(p[j].Parts) {
return len(p[i].Parts) < len(p[j].Parts)
}
// Equal, it doesn't matter
return false
}