/
util.go
67 lines (57 loc) · 1.34 KB
/
util.go
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package core
import "database/sql"
func toMap[T any, K comparable, V any](items []T, keyExtractor func(T) K, valueExtractor func(T) V) map[K]V {
m := make(map[K]V)
for _, item := range items {
m[keyExtractor(item)] = valueExtractor(item)
}
return m
}
func toMapSelf[T any, K comparable](items []T, keyExtractor func(T) K) map[K]T {
return toMap(items, keyExtractor, func(t T) T { return t })
}
func contains[K comparable, V any](m map[K]V, key K) bool {
_, found := m[key]
return found
}
func remove[T any](items []T, idx int) []T {
return append(items[:idx], items[idx+1:]...)
}
func removeFirstByPredicate[T any](items []T, predicate func(T) bool) []T {
for i, item := range items {
if predicate(item) {
return remove(items, i)
}
}
return items
}
func mapItems[T any, R any](items []T, mapper func(T) R) []R {
r := make([]R, len(items))
for i, item := range items {
r[i] = mapper(item)
}
return r
}
func filter[T any](items []T, predicate func(T) bool) []T {
var r []T
for _, item := range items {
if predicate(item) {
r = append(r, item)
}
}
return r
}
func fromNullString(s sql.NullString) *string {
if s.Valid {
return &s.String
} else {
return nil
}
}
func toNullString(s *string) sql.NullString {
if s != nil {
return sql.NullString{String: *s, Valid: true}
} else {
return sql.NullString{Valid: false}
}
}