/
util.go
105 lines (89 loc) · 2.17 KB
/
util.go
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package goe
import (
"fmt"
"github.com/EscanBE/go-ienumerable/goe/comparers"
"github.com/EscanBE/go-ienumerable/goe/reflection"
)
func (src *enumerable[T]) copyExceptData() *enumerable[T] {
if src == nil {
return nil
}
return &enumerable[T]{
data: nil,
dataType: src.dataType,
defaultComparer: src.defaultComparer,
}
}
func (src *enumerable[T]) withData(data []T) *enumerable[T] {
if src == nil {
return nil
}
src.data = data
return src
}
func (src *enumerable[T]) withEmptyData() *enumerable[T] {
if src == nil {
return nil
}
src.data = make([]T, 0)
return src
}
func copySlice[T any](src []T) []T {
dst := make([]T, len(src))
if len(src) > 0 {
copy(dst, src)
}
return dst
}
func (src *enumerable[T]) findDefaultComparer() comparers.IComparer[any] {
comparer, found := src.tryFindDefaultComparer()
if found {
return comparer
}
panic(fmt.Errorf("no default comparer registered for [%s]", src.dataType))
}
func (src *enumerable[T]) tryFindDefaultComparer() (comparers.IComparer[any], bool) {
if comparer, found := comparers.TryGetDefaultComparer[T](); found {
return comparer, true
}
return nil, false
}
func (src *enumerable[T]) injectDefaultComparer() IEnumerable[T] {
if comparer, found := src.tryFindDefaultComparer(); found {
src.defaultComparer = comparer
}
return src
}
func firstNotNil(values ...any) any {
for _, value := range values {
_, isNil := reflection.RootValueExtractor(value)
if !isNil {
return value
}
}
return nil
}
// cast IEnumerable back to *enumerable for accessing private fields.
func e[T any](ie IEnumerable[T]) *enumerable[T] {
return ie.(*enumerable[T])
}
// cast IEnumerable[T] to IEnumerable[any]
func asIEnumerableAny[T any](ie IEnumerable[T]) IEnumerable[any] {
if ie == nil {
return nil
}
return ie.Select(func(v T) any {
return v
})
}
// Ptr convert a value into pointer form,
// usually used to provide default value for methods like FirstOrDefault, LastOrDefault, SingleOrDefault,...
func Ptr[T any](value T) *T {
return &value
}
// SelfSelector is KeySelector that returns the element itself
func SelfSelector[T any]() KeySelector[T] {
return func(value T) any {
return value
}
}