nwillc

printV := func(values ...int) { fmt.Println(values) }
args := []int{1, 2, 3, 4}
printv(args...)
// output: [1 2 3 4]

nwillc

fmt.Println(rotate(rotate(1, 2, 3)))
// output: 3 1 2

nwillc

aa, bb, cc = bb, cc, aa
fmt.Println(aa, bb, cc)
// output: 3 1 2

nwillc

rotate := func(a, b, c int) (int, int, int) {
  return b, c, a
 }
 aa, bb, cc := rotate(1, 2, 3)
 fmt.Println(aa, bb, cc)
 // output: 2 3 1
 

nwillc

func foo() *Result[int] {...}

func fooBar() *Result[string] {
  return Map(foo(), func(i int) *Result[string] {
      return NewResult(fmt.Print(i))
    })
}

nwillc

type Result[T any] struct {
   //...
}
// NewResult for a value.
func NewResult[T any](t T) *Result[T] {...}

// NewResultError creates a Result from a value, error tuple.
func NewResultError[T any](t T, err error) *Result[T] {...}

// NewError for an error.

nwillc

// This returns a single error and mutates v!
func json.Unmarshal(data []byte, v any) error {}
// This mutates b and returns an int and an error.
func (f *File) os.ReadAt(b []byte, off int64) (n int, err error)

nwillc

func foo() (int, error) {...}

func fooBar() (string, error) {
  value, err := foo()
  if err != nil {
    return 0, err
  }
  // ...
  return fmt.Print(value), nil
}

nwillc

// All returns true if all elements in the sequence match the predicate.
func All[T any](sequence Sequence[T], predicate func(t T) bool) bool {...}

// Any returns true if any element of the sequence matches the predicate.
func Any[T any](sequence Sequence[T], predicate func(t T) bool) bool {...}

// Compare two sequences with a comparator returning less/equal/greater (-1/0/1) and return comparison of the two.
func Compare[T any](s1, s2 Sequence[T], comparator func(t1, t2 T) int) int {...}

// Find returns the first element matching the given predicate, or Result error of NoSuchElement if not found.

nwillc

func CaculateSomething(i int) (result int, err error) {
  // Does a bunch of math to calculate a value, or
  // returns an error when it can't.
  done := false
  defer func() {
    if !done {
      err = fmt.Errorf("panic: %+v", recover())
    }
  }()
  // ... the magic ...