Pundi kaya generics ana gawe ing Go?

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Accepted Answer

**Generics** (ditambahake ing Go 1.18) ngidini sampeyan nulis fungsi lan tipe sing bisa gunakake kanggo **pirang-pirang tipe** liwat parameter tipe, nalika njaga keamanan tipe ing wektu kompilasi. Dheweke ngilangi kompromi lawas antara nduplikasi kode saben tipe utawa ilang keamanan nganggo `interface{}`.

## Masalah sing diselesaike generics

```go
// ❌ before generics — either duplicate per type...
func MaxInt(a, b int) int { ... }
func MaxFloat(a, b float64) float64 { ... }   // copy-paste for each type

// ...or use interface{} and lose type safety + need casts/assertions
func Max(a, b interface{}) interface{} { ... }   // unsafe, clunky
```

## Fungsi generik

```go
// T is a type parameter constrained to be "ordered" (comparable with < >)
func Max[T constraints.Ordered](a, b T) T {
    if a > b {
        return a
    }
    return b
}

Max(3, 5)         // T inferred as int → 5
Max(2.5, 1.1)     // T inferred as float64 → 2.5
Max("a", "b")     // T inferred as string → "b"
```

`[T constraints.Ordered]` ngumumake parameter tipe `T` nganggo **kendala** (tipe apa sing diperbolehake). Kompiler nyimpulake `T` saka argumen — siji implementasi bisa digunakake kanggo pirang-pirang tipe, kabeh-kabeh type-safe.

## Kendala tipe

```go
// a constraint is an interface listing allowed types or required methods
type Number interface {
    ~int | ~int64 | ~float64        // the | union means "any of these"
}

func Sum[T Number](nums []T) T {
    var total T
    for _, n := range nums {
        total += n                   // safe — T is constrained to numeric types
    }
    return total
}
Sum([]int{1, 2, 3})       // 6
Sum([]float64{1.5, 2.5})  // 4.0

// built-in constraints:
any                        // any type (alias for interface{})
comparable                 // types usable with == (for map keys, etc.)
// golang.org/x/exp/constraints: Ordered, Integer, Float, etc.
```

Kendala nemtokake operasi apa sing valid ing parameter tipe (tanda `~` tegese "bab-bab tipe apa wae sing tipe dasarane iki").

## Tipe generik

```go
// a generic stack that works for any type
type Stack[T any] struct {
    items []T
}
func (s *Stack[T]) Push(item T) { s.items = append(s.items, item) }
func (s *Stack[T]) Pop() T {
    item := s.items[len(s.items)-1]
    s.items = s.items[:len(s.items)-1]
    return item
}

intStack := Stack[int]{}       // a stack of ints
strStack := Stack[string]{}     // a stack of strings — same code
```

## Kapan gunakake (lan ora) generics

```text
✓ Generic data structures (stacks, trees, sets), utility functions over collections
  (Map, Filter, Reduce), type-safe containers
✗ Don't overuse — if interfaces or a concrete type work simply, prefer them.
  Go's philosophy still favors simplicity; generics are a tool, not a default.
```

## Dene iku penting

Generics minangka tambahan Go sing penting lan ditunggu-tunggu (1.18) sing ngatasi masalah nyata: sadurunge, nulis kode sing bisa diulang kanggo pirang-pirang tipe meksa sampeyan nduplikasi kode saben tipe (padhai, ora gampang dirawat) utawa nganggo `interface{}` (ilang keamanan tipe ing wektu kompilasi lan mbutuhake pernyataan runtime).

Generics ngidini sampeyan nulis fungsi sing type-safe lan bisa diulang lan struktur data (wadah, utility koleksi kaya Map/Filter/Reduce) sekali, karo kompiler sing ngetrapake karusakan lan nyimpulake tipe.

Ngerteni parameter tipe, kendala (kapala `any`, `comparable`, lan sintaks union/`~`), lan tipe generik saya-saya dadi penting nalika ekosistem nerangake dheweke.

Sabar penting kaya iku cara pikir Go yen generics minangka **alat kanggo panggunaan sejati, ora standar asale** — nggunakake dheweke berlebihan bali marang filosofi kesederhanaan Go.

Iki minangka topik kiwari, sing kerep dirembug sing nggambarake kalokaripan karo Go modern.