[dev.go2go] cmd/go2go: in testdata, drop type keyword, always provide constraint

This is a rewrite of the tests to drop the type keyword for parameterized
functions and types, and to instead always provide a constraint.

We can revert if we don't like this approach.

Change-Id: I9cd097b8db2aa3c84a40a7aeaa10246ab3b990dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/248897
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/go2go/testdata/go2path/src/alg/alg.go2

@@ -8,7 +8,7 @@ package alg
 import "constraints"
 
 // Max returns the maximum of two values of some ordered type.
-func Max[type T constraints.Ordered](a, b T) T {
+func Max[T constraints.Ordered](a, b T) T {
 	if a < b {
 		return b
 	}
@@ -16,7 +16,7 @@ func Max[type T constraints.Ordered](a, b T) T {
 }
 
 // Min returns the minimum of two values of some ordered type.
-func Min[type T constraints.Ordered](a, b T) T {
+func Min[T constraints.Ordered](a, b T) T {
 	if a < b {
 		return a
 	}

src/cmd/go2go/testdata/go2path/src/chans/chans.go2

@@ -12,7 +12,7 @@ import (
 
 // ReadAll reads from c until the channel is closed or the context is
 // canceled, returning all the values read.
-func ReadAll[type Elem](ctx context.Context, c <-chan Elem) []Elem {
+func ReadAll[Elem any](ctx context.Context, c <-chan Elem) []Elem {
 	var r []Elem
 	for {
 		select {
@@ -30,7 +30,7 @@ func ReadAll[type Elem](ctx context.Context, c <-chan Elem) []Elem {
 // Merge merges two channels into a single channel.
 // This will leave a goroutine running until either both channels are closed
 // or the context is canceled, at which point the returned channel is closed.
-func Merge[type Elem](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem {
+func Merge[Elem any](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem {
 	r := make(chan Elem)
 	go func(ctx context.Context, c1, c2 <-chan Elem, r chan<- Elem) {
 		defer close(r)
@@ -60,7 +60,7 @@ func Merge[type Elem](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem {
 // is sent on the returned channel. This will leave a goroutine running
 // until c is closed or the context is canceled, at which point the
 // returned channel is closed.
-func Filter[type Elem](ctx context.Context, c <-chan Elem, f func(Elem) bool) <-chan Elem {
+func Filter[Elem any](ctx context.Context, c <-chan Elem, f func(Elem) bool) <-chan Elem {
 	r := make(chan Elem)
 	go func(ctx context.Context, c <-chan Elem, f func(Elem) bool, r chan<- Elem) {
 		defer close(r)
@@ -84,7 +84,7 @@ func Filter[type Elem](ctx context.Context, c <-chan Elem, f func(Elem) bool) <-
 // Sink returns a channel that discards all values sent to it.
 // This will leave a goroutine running until the context is canceled
 // or the returned channel is closed.
-func Sink[type Elem](ctx context.Context) chan<- Elem {
+func Sink[Elem any](ctx context.Context) chan<- Elem {
 	r := make(chan Elem)
 	go func(ctx context.Context, r <-chan Elem) {
 		for {
@@ -103,12 +103,12 @@ func Sink[type Elem](ctx context.Context) chan<- Elem {
 
 // An Exclusive is a value that may only be used by a single goroutine
 // at a time. This is implemented using channels rather than a mutex.
-type Exclusive[type Val] struct {
+type Exclusive[Val any] struct {
 	c chan Val
 }
 
 // MakeExclusive makes an initialized exclusive value.
-func MakeExclusive[type Val](initial Val) *Exclusive[Val] {
+func MakeExclusive[Val any](initial Val) *Exclusive[Val] {
 	r := &Exclusive[Val]{
 		c: make(chan Val, 1),
 	}
@@ -152,7 +152,7 @@ func (e *Exclusive[Val]) Release(v Val) {
 //
 // This is a convenient way to exit a goroutine sending values when
 // the receiver stops reading them.
-func Ranger[type Elem]() (*Sender[Elem], *Receiver[Elem]) {
+func Ranger[Elem any]() (*Sender[Elem], *Receiver[Elem]) {
 	c := make(chan Elem)
 	d := make(chan struct{})
 	s := &Sender[Elem]{
@@ -168,7 +168,7 @@ func Ranger[type Elem]() (*Sender[Elem], *Receiver[Elem]) {
 }
 
 // A Sender is used to send values to a Receiver.
-type Sender[type Elem] struct {
+type Sender[Elem any] struct {
 	values chan<- Elem
 	done   <-chan struct{}
 }
@@ -194,7 +194,7 @@ func (s *Sender[Elem]) Close() {
 }
 
 // A Receiver receives values from a Sender.
-type Receiver[type Elem] struct {
+type Receiver[Elem any] struct {
 	values <-chan Elem
 	done   chan<- struct{}
 }

src/cmd/go2go/testdata/go2path/src/graph/graph.go2

@@ -10,31 +10,31 @@ import "errors"
 // A Graph is a collection of nodes. A node may have an arbitrary number
 // of edges. An edge connects two nodes. Both nodes and edges must be
 // comparable. This is an undirected simple graph.
-type Graph[type Node NodeC[Edge], Edge EdgeC[Node]] struct {
+type Graph[Node NodeC[Edge], Edge EdgeC[Node]] struct {
 	nodes []Node
 }
 
 // NodeC is the contraints on a node in a graph, given the Edge type.
-type NodeC[type Edge] interface {
+type NodeC[Edge any] interface {
 	comparable
 	Edges() []Edge
 }
 
 // Edgec is the constraints on an edge in a graph, given the Node type.
-type EdgeC[type Node] interface {
+type EdgeC[Node any] interface {
 	comparable
 	Nodes() (a, b Node)
 }
 
 // New creates a new Graph from a collection of Nodes.
-func New[type Node NodeC[Edge], Edge EdgeC[Node]](nodes []Node) *Graph[Node, Edge] {
+func New[Node NodeC[Edge], Edge EdgeC[Node]](nodes []Node) *Graph[Node, Edge] {
 	return &Graph[Node, Edge]{nodes: nodes}
 }
 
 // nodePath holds the path to a node during ShortestPath.
 // This should ideally be a type defined inside ShortestPath,
 // but the translator tool doesn't support that.
-type nodePath[type Node NodeC[Edge], Edge EdgeC[Node]] struct {
+type nodePath[Node NodeC[Edge], Edge EdgeC[Node]] struct {
 	node Node
 	path []Edge
 }
@@ -79,12 +79,12 @@ type GraphP[type *Node NodeCP[Edge], *Edge EdgeCP[Node]] struct {
 }
 
 // NodeCP is the contraint on a Node in a GraphP.
-type NodeCP[type Edge] interface {
+type NodeCP[Edge any] interface {
 	Edges() []*Edge
 }
 
 // EdgeCP is the contraint on an Edge in a GraphP.
-type EdgeCP[type Node] interface {
+type EdgeCP[Node any] interface {
 	Nodes() (a, b *Node)
 }
 

src/cmd/go2go/testdata/go2path/src/gsort/gsort.go2

@@ -12,7 +12,7 @@ import (
 )
 
 // orderedSlice is a slice of values of some ordered type.
-type orderedSlice[type Elem constraints.Ordered] []Elem
+type orderedSlice[Elem constraints.Ordered] []Elem
 
 // orderedSlice implements sort.Interface.
 
@@ -30,13 +30,13 @@ func (s orderedSlice[Elem]) Less(i, j int) bool {
 func (s orderedSlice[Elem]) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 
 // OrderedSlice sorts a slice of any ordered type in ascending order.
-func OrderedSlice[type Elem constraints.Ordered](s []Elem) {
+func OrderedSlice[Elem constraints.Ordered](s []Elem) {
 	sort.Sort(orderedSlice[Elem](s))
 }
 
 // sliceFn implements sort.Interface for a slice of any type with an
 // explicit less-than function.
-type sliceFn[type Elem] struct {
+type sliceFn[Elem any] struct {
 	s    []Elem
 	less func(Elem, Elem) bool
 }
@@ -46,6 +46,6 @@ func (s sliceFn[Elem]) Less(i, j int) bool { return s.less(s.s[i], s.s[j]) }
 func (s sliceFn[Elem]) Swap(i, j int)      { s.s[i], s.s[j] = s.s[j], s.s[i] }
 
 // SliceFn sorts a slice of any type according to a less-than function.
-func SliceFn[type Elem](s []Elem, less func(Elem, Elem) bool) {
+func SliceFn[Elem any](s []Elem, less func(Elem, Elem) bool) {
 	sort.Sort(sliceFn[Elem]{s, less})
 }

src/cmd/go2go/testdata/go2path/src/gsort/gsort_test.go2

@@ -31,7 +31,7 @@ func TestSortOrderedStrings(t *testing.T) {
 	testOrdered(t, strs, sort.Strings)
 }
 
-func testOrdered[type Elem constraints.Ordered](t *testing.T, s []Elem, sorter func([]Elem)) {
+func testOrdered[Elem constraints.Ordered](t *testing.T, s []Elem, sorter func([]Elem)) {
 	s1 := make([]Elem, len(s))
 	copy(s1, s)
 	s2 := make([]Elem, len(s))

src/cmd/go2go/testdata/go2path/src/list/list.go2

@@ -9,7 +9,7 @@ package list
 // perhaps with different type names.
 
 // Element is an element of a linked list.
-type Element[type TElem] struct {
+type Element[TElem any] struct {
 	// Next and previous pointers in the doubly-linked list of elements.
 	// To simplify the implementation, internally a list l is implemented
 	// as a ring, such that &l.root is both the next element of the last
@@ -42,7 +42,7 @@ func (e *Element[TElem]) Prev() *Element[TElem] {
 
 // List represents a doubly linked list.
 // The zero value for List is an empty list ready to use.
-type List[type TElem] struct {
+type List[TElem any] struct {
 	root Element[TElem] // sentinel list element, only &root, root.prev, and root.next are used
 	len  int     // current list length excluding (this) sentinel element
 }
@@ -56,7 +56,7 @@ func (l *List[TElem]) Init() *List[TElem] {
 }
 
 // New returns an initialized list.
-func New[type TElem]() *List[TElem] { return new(List[TElem]).Init() }
+func New[TElem any]() *List[TElem] { return new(List[TElem]).Init() }
 
 // Len returns the number of elements of list l.
 // The complexity is O(1).
@@ -235,7 +235,7 @@ func (l *List[TElem]) PushFrontList(other *List[TElem]) {
 }
 
 // Transform runs a transform function on a list returning a new list.
-func Transform[type TElem1, TElem2](lst *List[TElem1], f func(TElem1) TElem2) *List[TElem2] {
+func Transform[TElem1, TElem2 any](lst *List[TElem1], f func(TElem1) TElem2) *List[TElem2] {
 	ret := New[TElem2]()
 	for p := lst.Front(); p != nil; p = p.Next() {
 		ret.PushBack(f(p.Value))

src/cmd/go2go/testdata/go2path/src/list/list_test.go2

@@ -9,7 +9,7 @@ import (
 	"testing"
 )
 
-func checkListLen[type TElem](t *testing.T, l *List[TElem], len int) bool {
+func checkListLen[TElem any](t *testing.T, l *List[TElem], len int) bool {
 	if n := l.Len(); n != len {
 		t.Errorf("l.Len() = %d, want %d", n, len)
 		return false
@@ -17,7 +17,7 @@ func checkListLen[type TElem](t *testing.T, l *List[TElem], len int) bool {
 	return true
 }
 
-func checkListPointers[type TElem](t *testing.T, l *List[TElem], es []*Element[TElem]) {
+func checkListPointers[TElem any](t *testing.T, l *List[TElem], es []*Element[TElem]) {
 	root := &l.root
 
 	if !checkListLen(t, l, len(es)) {
@@ -143,7 +143,7 @@ func TestList(t *testing.T) {
 	checkListPointers(t, l2, []*(Element[int]){})
 }
 
-func checkList[type TElem comparable](t *testing.T, l *List[TElem], es []interface{}) {
+func checkList[TElem comparable](t *testing.T, l *List[TElem], es []interface{}) {
 	if !checkListLen(t, l, len(es)) {
 		return
 	}

src/cmd/go2go/testdata/go2path/src/maps/maps.go2

@@ -5,12 +5,9 @@
 // Package maps implements simple functions to manipulate maps in various ways.
 package maps
 
-// any is a convenient type bound.
-type any interface{}
-
 // Keys returns the keys of the map m.
 // The keys will be an indeterminate order.
-func Keys[type K comparable, V any](m map[K]V) []K {
+func Keys[K comparable, V any](m map[K]V) []K {
 	r := make([]K, 0, len(m))
 	for k := range m {
 		r = append(r, k)
@@ -20,7 +17,7 @@ func Keys[type K comparable, V any](m map[K]V) []K {
 
 // Values returns the values of the map m.
 // The values will be in an indeterminate order.
-func Values[type K comparable, V any](m map[K]V) []V {
+func Values[K comparable, V any](m map[K]V) []V {
 	r := make([]V, 0, len(m))
 	for _, v := range m {
 		r = append(r, v)
@@ -30,7 +27,7 @@ func Values[type K comparable, V any](m map[K]V) []V {
 
 // Equal reports whether two maps contain the same key/value pairs.
 // Values are compared using ==.
-func Equal[type K, V comparable](m1, m2 map[K]V) bool {
+func Equal[K, V comparable](m1, m2 map[K]V) bool {
 	if len(m1) != len(m2) {
 		return false
 	}
@@ -43,7 +40,7 @@ func Equal[type K, V comparable](m1, m2 map[K]V) bool {
 }
 
 // Copy returns a copy of m.
-func Copy[type K comparable, V any](m map[K]V) map[K]V {
+func Copy[K comparable, V any](m map[K]V) map[K]V {
 	r := make(map[K]V, len(m))
 	for k, v := range m {
 		r[k] = v
@@ -53,7 +50,7 @@ func Copy[type K comparable, V any](m map[K]V) map[K]V {
 
 // Add adds all key/value pairs in m2 to m1. Keys in m2 that are already
 // present in m1 will be overwritten with the value in m2.
-func Add[type K comparable, V any](m1, m2 map[K]V) {
+func Add[K comparable, V any](m1, m2 map[K]V) {
 	for k, v := range m2 {
 		m1[k] = v
 	}
@@ -61,7 +58,7 @@ func Add[type K comparable, V any](m1, m2 map[K]V) {
 
 // Sub removes all keys in m2 from m1. Keys in m2 that are not present
 // in m1 are ignored. The values in m2 are ignored.
-func Sub[type K comparable, V any](m1, m2 map[K]V) {
+func Sub[K comparable, V any](m1, m2 map[K]V) {
 	for k := range m2 {
 		delete(m1, k)
 	}
@@ -69,7 +66,7 @@ func Sub[type K comparable, V any](m1, m2 map[K]V) {
 
 // Intersect removes all keys from m1 that are not present in m2.
 // Keys in m2 that are not in m1 are ignored. The values in m2 are ignored.
-func Intersect[type K comparable, V any](m1, m2 map[K]V) {
+func Intersect[K comparable, V any](m1, m2 map[K]V) {
 	for k := range m1 {
 		if _, ok := m2[k]; !ok {
 			delete(m1, k)
@@ -78,7 +75,7 @@ func Intersect[type K comparable, V any](m1, m2 map[K]V) {
 }
 
 // Filter deletes any key/value pairs from m for which f returns false.
-func Filter[type K comparable, V any](m map[K]V, f func(K, V) bool) {
+func Filter[K comparable, V any](m map[K]V, f func(K, V) bool) {
 	for k, v := range m {
 		if !f(k, v) {
 			delete(m, k)
@@ -87,7 +84,7 @@ func Filter[type K comparable, V any](m map[K]V, f func(K, V) bool) {
 }
 
 // TransformValues applies f to each value in m. The keys remain unchanged.
-func TransformValues[type K comparable, V any](m map[K]V, f func(V) V) {
+func TransformValues[K comparable, V any](m map[K]V, f func(V) V) {
 	for k, v := range m {
 		m[k] = f(v)
 	}

src/cmd/go2go/testdata/go2path/src/metrics/metrics.go2

@@ -13,7 +13,7 @@ import (
 )
 
 // Metric1 tracks metrics of values of some type.
-type Metric1[type T comparable] struct {
+type Metric1[T comparable] struct {
 	mu sync.Mutex
 	m  map[T]int
 }
@@ -40,13 +40,13 @@ func (m *Metric1[T]) Metrics() []T {
 	return maps.Keys(m.m)
 }
 
-type key2[type T1, T2 comparable] struct {
+type key2[T1, T2 comparable] struct {
 	f1 T1
 	f2 T2
 }
 
 // Metric2 tracks metrics of pairs of values.
-type Metric2[type T1, T2 comparable] struct {
+type Metric2[T1, T2 comparable] struct {
 	mu sync.Mutex
 	m  map[key2[T1, T2]]int
 }
@@ -77,14 +77,14 @@ func (m *Metric2[T1, T2]) Metrics() (r1 []T1, r2 []T2) {
 	return r1, r2
 }
 
-type key3[type T1, T2, T3 comparable] struct {
+type key3[T1, T2, T3 comparable] struct {
 	f1 T1
 	f2 T2
 	f3 T3
 }
 
 // Metric3 tracks metrics of triplets of values.
-type Metric3[type T1, T2, T3 comparable] struct {
+type Metric3[T1, T2, T3 comparable] struct {
 	mu sync.Mutex
 	m  map[key3[T1, T2, T3]]int
 }

src/cmd/go2go/testdata/go2path/src/orderedmap/orderedmap.go2

@@ -15,13 +15,13 @@ import (
 )
 
 // Map is an ordered map.
-type Map[type K, V] struct {
+type Map[K, V any] struct {
 	root    *node[K, V]
 	compare func(K, K) int
 }
 
 // node is the type of a node in the binary tree.
-type node[type K, V] struct {
+type node[K, V any] struct {
 	key         K
 	val         V
 	left, right *node[K, V]
@@ -30,14 +30,14 @@ type node[type K, V] struct {
 // New returns a new map. It takes a comparison function that compares two
 // keys and returns < 0 if the first is less, == 0 if they are equal,
 // > 0 if the first is greater.
-func New[type K, V](compare func(K, K) int) *Map[K, V] {
+func New[K, V any](compare func(K, K) int) *Map[K, V] {
 	return &Map[K, V]{compare: compare}
 }
 
 // NewOrdered returns a new map whose key is an ordered type.
 // This is like New, but does not require providing a compare function.
 // The map compare function uses the obvious key ordering.
-func NewOrdered[type K constraints.Ordered, V interface{}]() *Map[K, V] {
+func NewOrdered[K constraints.Ordered, V any]() *Map[K, V] {
 	return New[K, V](func(k1, k2 K) int {
 		switch {
 		case k1 < k2:
@@ -92,7 +92,7 @@ func (m *Map[K, V]) Find(key K) (V, bool) {
 }
 
 // keyValue is a pair of key and value used while iterating.
-type keyValue[type K, V] struct {
+type keyValue[K, V any] struct {
 	key K
 	val V
 }
@@ -119,7 +119,7 @@ func (m *Map[K, V]) Iterate() *Iterator[K, V] {
 }
 
 // Iterator is used to iterate over the map.
-type Iterator[type K, V] struct {
+type Iterator[K, V any] struct {
 	r *chans.Receiver[keyValue[K, V]]
 }
 

src/cmd/go2go/testdata/go2path/src/sets/sets.go2

@@ -6,12 +6,12 @@
 package sets
 
 // A Set is a set of elements of some type.
-type Set[type Elem comparable] struct {
+type Set[Elem comparable] struct {
 	m map[Elem]struct{}
 }
 
 // Make makes a new set.
-func Make[type Elem comparable]() Set[Elem] {
+func Make[Elem comparable]() Set[Elem] {
 	return Set[Elem]{m: make(map[Elem]struct{})}
 }
 
@@ -48,7 +48,7 @@ func (s Set[Elem]) Values() []Elem {
 }
 
 // Equal reports whether two sets contain the same elements.
-func Equal[type Elem comparable](s1, s2 Set[Elem]) bool {
+func Equal[Elem comparable](s1, s2 Set[Elem]) bool {
 	if len(s1.m) != len(s2.m) {
 		return false
 	}

src/cmd/go2go/testdata/go2path/src/slices/slices.go2

@@ -13,7 +13,7 @@ import (
 
 // Equal reports whether two slices are equal: the same length and all
 // elements equal. All floating point NaNs are considered equal.
-func Equal[type Elem comparable](s1, s2 []Elem) bool {
+func Equal[Elem comparable](s1, s2 []Elem) bool {
 	if len(s1) != len(s2) {
 		return false
 	}
@@ -31,7 +31,7 @@ func Equal[type Elem comparable](s1, s2 []Elem) bool {
 
 // EqualFn reports whether two slices are equal using a comparision
 // function on each element.
-func EqualFn[type Elem](s1, s2 []Elem, eq func(Elem, Elem) bool) bool {
+func EqualFn[Elem any](s1, s2 []Elem, eq func(Elem, Elem) bool) bool {
 	if len(s1) != len(s2) {
 		return false
 	}
@@ -45,7 +45,7 @@ func EqualFn[type Elem](s1, s2 []Elem, eq func(Elem, Elem) bool) bool {
 }
 
 // Map turns a []Elem1 to a []Elem2 using a mapping function.
-func Map[type Elem1, Elem2](s []Elem1, f func(Elem1) Elem2) []Elem2 {
+func Map[Elem1, Elem2 any](s []Elem1, f func(Elem1) Elem2) []Elem2 {
 	r := make([]Elem2, len(s))
 	for i, v := range s {
 		r[i] = f(v)
@@ -55,7 +55,7 @@ func Map[type Elem1, Elem2](s []Elem1, f func(Elem1) Elem2) []Elem2 {
 
 // Reduce reduces a []Elem1 to a single value of type Elem2 using
 // a reduction function.
-func Reduce[type Elem1, Elem2](s []Elem1, initializer Elem2, f func(Elem2, Elem1) Elem2) Elem2 {
+func Reduce[Elem1, Elem2 any](s []Elem1, initializer Elem2, f func(Elem2, Elem1) Elem2) Elem2 {
 	r := initializer
 	for _, v := range s {
 		r = f(r, v)
@@ -64,7 +64,7 @@ func Reduce[type Elem1, Elem2](s []Elem1, initializer Elem2, f func(Elem2, Elem1
 }
 
 // Filter filters values from a slice using a filter function.
-func Filter[type Elem](s []Elem, f func(Elem) bool) []Elem {
+func Filter[Elem any](s []Elem, f func(Elem) bool) []Elem {
 	var r []Elem
 	for _, v := range s {
 		if f(v) {
@@ -76,7 +76,7 @@ func Filter[type Elem](s []Elem, f func(Elem) bool) []Elem {
 
 // Max returns the maximum element in a slice of some ordered type.
 // If the slice is empty it returns the zero value of the element type.
-func Max[type Elem constraints.Ordered](s []Elem) Elem {
+func Max[Elem constraints.Ordered](s []Elem) Elem {
 	if len(s) == 0 {
 		var zero Elem
 		return zero
@@ -86,7 +86,7 @@ func Max[type Elem constraints.Ordered](s []Elem) Elem {
 
 // Min returns the minimum element in a slice of some ordered type.
 // If the slice is empty it returns the zero value of the element type.
-func Min[type Elem constraints.Ordered](s []Elem) Elem {
+func Min[Elem constraints.Ordered](s []Elem) Elem {
 	if len(s) == 0 {
 		var zero Elem
 		return zero
@@ -99,7 +99,7 @@ func Min[type Elem constraints.Ordered](s []Elem) Elem {
 // of how to write it using generics. We used to write code like
 // this before append was added to the language, but we had to write
 // a separate copy for each type.
-func Append[type T](s []T, t ...T) []T {
+func Append[T any](s []T, t ...T) []T {
 	lens := len(s)
 	tot := lens + len(t)
 	if tot <= cap(s) {
@@ -116,7 +116,7 @@ func Append[type T](s []T, t ...T) []T {
 // Copy copies values from t to s, stopping when either slice is full,
 // returning the number of values copied. This is like the predeclared
 // copy function; it's an example of how to write it using generics.
-func Copy[type T](s, t []T) int {
+func Copy[T any](s, t []T) int {
 	i := 0
 	for ; i < len(s) && i < len(t); i++ {
 		s[i] = t[i]

src/cmd/go2go/testdata/go2path/src/slices/slices_test.go2

@@ -42,7 +42,7 @@ func TestEqual(t *testing.T) {
 	}
 }
 
-func offByOne[type Elem constraints.Integer](a, b Elem) bool {
+func offByOne[Elem constraints.Integer](a, b Elem) bool {
 	return a == b + 1 || a == b - 1
 }