76 lines
1.9 KiB
Go
76 lines
1.9 KiB
Go
|
// Package aghalgo contains common generic algorithms and data structures.
|
||
|
|
//
|
||
|
|
// TODO(a.garipov): Update to use type parameters in Go 1.18.
|
||
|
|
package aghalgo
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"sort"
|
||
|
|
)
|
||
|
|
|
||
|
|
// comparable is an alias for interface{}. Values passed as arguments of this
|
||
|
|
// type alias must be comparable.
|
||
|
|
//
|
||
|
|
// TODO(a.garipov): Remove in Go 1.18.
|
||
|
|
type comparable = interface{}
|
||
|
|
|
||
|
|
// UniquenessValidator allows validating uniqueness of comparable items.
|
||
|
|
type UniquenessValidator map[comparable]int64
|
||
|
|
|
||
|
|
// Add adds a value to the validator. v must not be nil.
|
||
|
|
func (v UniquenessValidator) Add(elems ...comparable) {
|
||
|
|
for _, e := range elems {
|
||
|
|
v[e]++
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Merge returns a validator containing data from both v and other.
|
||
|
|
func (v UniquenessValidator) Merge(other UniquenessValidator) (merged UniquenessValidator) {
|
||
|
|
merged = make(UniquenessValidator, len(v)+len(other))
|
||
|
|
for elem, num := range v {
|
||
|
|
merged[elem] += num
|
||
|
|
}
|
||
|
|
|
||
|
|
for elem, num := range other {
|
||
|
|
merged[elem] += num
|
||
|
|
}
|
||
|
|
|
||
|
|
return merged
|
||
|
|
}
|
||
|
|
|
||
|
|
// Validate returns an error enumerating all elements that aren't unique.
|
||
|
|
// isBefore is an optional sorting function to make the error message
|
||
|
|
// deterministic.
|
||
|
|
func (v UniquenessValidator) Validate(isBefore func(a, b comparable) (less bool)) (err error) {
|
||
|
|
var dup []comparable
|
||
|
|
for elem, num := range v {
|
||
|
|
if num > 1 {
|
||
|
|
dup = append(dup, elem)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if len(dup) == 0 {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
if isBefore != nil {
|
||
|
|
sort.Slice(dup, func(i, j int) (less bool) {
|
||
|
|
return isBefore(dup[i], dup[j])
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
return fmt.Errorf("duplicated values: %v", dup)
|
||
|
|
}
|
||
|
|
|
||
|
|
// IntIsBefore is a helper sort function for UniquenessValidator.Validate.
|
||
|
|
// a and b must be of type int.
|
||
|
|
func IntIsBefore(a, b comparable) (less bool) {
|
||
|
|
return a.(int) < b.(int)
|
||
|
|
}
|
||
|
|
|
||
|
|
// StringIsBefore is a helper sort function for UniquenessValidator.Validate.
|
||
|
|
// a and b must be of type string.
|
||
|
|
func StringIsBefore(a, b comparable) (less bool) {
|
||
|
|
return a.(string) < b.(string)
|
||
|
|
}
|