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Diffstat (limited to 'test/typeparam/sets.go')
-rw-r--r-- | test/typeparam/sets.go | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/test/typeparam/sets.go b/test/typeparam/sets.go new file mode 100644 index 0000000..bd08ad7 --- /dev/null +++ b/test/typeparam/sets.go @@ -0,0 +1,280 @@ +// run + +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +import ( + "fmt" + "sort" +) + +// _Equal reports whether two slices are equal: the same length and all +// elements equal. All floating point NaNs are considered equal. +func _SliceEqual[Elem comparable](s1, s2 []Elem) bool { + if len(s1) != len(s2) { + return false + } + for i, v1 := range s1 { + v2 := s2[i] + if v1 != v2 { + isNaN := func(f Elem) bool { return f != f } + if !isNaN(v1) || !isNaN(v2) { + return false + } + } + } + return true +} + +// A _Set is a set of elements of some type. +type _Set[Elem comparable] struct { + m map[Elem]struct{} +} + +// _Make makes a new set. +func _Make[Elem comparable]() _Set[Elem] { + return _Set[Elem]{m: make(map[Elem]struct{})} +} + +// Add adds an element to a set. +func (s _Set[Elem]) Add(v Elem) { + s.m[v] = struct{}{} +} + +// Delete removes an element from a set. If the element is not present +// in the set, this does nothing. +func (s _Set[Elem]) Delete(v Elem) { + delete(s.m, v) +} + +// Contains reports whether v is in the set. +func (s _Set[Elem]) Contains(v Elem) bool { + _, ok := s.m[v] + return ok +} + +// Len returns the number of elements in the set. +func (s _Set[Elem]) Len() int { + return len(s.m) +} + +// Values returns the values in the set. +// The values will be in an indeterminate order. +func (s _Set[Elem]) Values() []Elem { + r := make([]Elem, 0, len(s.m)) + for v := range s.m { + r = append(r, v) + } + return r +} + +// _Equal reports whether two sets contain the same elements. +func _Equal[Elem comparable](s1, s2 _Set[Elem]) bool { + if len(s1.m) != len(s2.m) { + return false + } + for v1 := range s1.m { + if !s2.Contains(v1) { + return false + } + } + return true +} + +// Copy returns a copy of s. +func (s _Set[Elem]) Copy() _Set[Elem] { + r := _Set[Elem]{m: make(map[Elem]struct{}, len(s.m))} + for v := range s.m { + r.m[v] = struct{}{} + } + return r +} + +// AddSet adds all the elements of s2 to s. +func (s _Set[Elem]) AddSet(s2 _Set[Elem]) { + for v := range s2.m { + s.m[v] = struct{}{} + } +} + +// SubSet removes all elements in s2 from s. +// Values in s2 that are not in s are ignored. +func (s _Set[Elem]) SubSet(s2 _Set[Elem]) { + for v := range s2.m { + delete(s.m, v) + } +} + +// Intersect removes all elements from s that are not present in s2. +// Values in s2 that are not in s are ignored. +func (s _Set[Elem]) Intersect(s2 _Set[Elem]) { + for v := range s.m { + if !s2.Contains(v) { + delete(s.m, v) + } + } +} + +// Iterate calls f on every element in the set. +func (s _Set[Elem]) Iterate(f func(Elem)) { + for v := range s.m { + f(v) + } +} + +// Filter deletes any elements from s for which f returns false. +func (s _Set[Elem]) Filter(f func(Elem) bool) { + for v := range s.m { + if !f(v) { + delete(s.m, v) + } + } +} + +func TestSet() { + s1 := _Make[int]() + if got := s1.Len(); got != 0 { + panic(fmt.Sprintf("Len of empty set = %d, want 0", got)) + } + s1.Add(1) + s1.Add(1) + s1.Add(1) + if got := s1.Len(); got != 1 { + panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got)) + } + s1.Add(2) + s1.Add(3) + s1.Add(4) + if got := s1.Len(); got != 4 { + panic(fmt.Sprintf("(%v).Len() == %d, want 4", s1, got)) + } + if !s1.Contains(1) { + panic(fmt.Sprintf("(%v).Contains(1) == false, want true", s1)) + } + if s1.Contains(5) { + panic(fmt.Sprintf("(%v).Contains(5) == true, want false", s1)) + } + vals := s1.Values() + sort.Ints(vals) + w1 := []int{1, 2, 3, 4} + if !_SliceEqual(vals, w1) { + panic(fmt.Sprintf("(%v).Values() == %v, want %v", s1, vals, w1)) + } +} + +func TestEqual() { + s1 := _Make[string]() + s2 := _Make[string]() + if !_Equal(s1, s2) { + panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2)) + } + s1.Add("hello") + s1.Add("world") + if got := s1.Len(); got != 2 { + panic(fmt.Sprintf("(%v).Len() == %d, want 2", s1, got)) + } + if _Equal(s1, s2) { + panic(fmt.Sprintf("_Equal(%v, %v) = true, want false", s1, s2)) + } +} + +func TestCopy() { + s1 := _Make[float64]() + s1.Add(0) + s2 := s1.Copy() + if !_Equal(s1, s2) { + panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2)) + } + s1.Add(1) + if _Equal(s1, s2) { + panic(fmt.Sprintf("_Equal(%v, %v) = true, want false", s1, s2)) + } +} + +func TestAddSet() { + s1 := _Make[int]() + s1.Add(1) + s1.Add(2) + s2 := _Make[int]() + s2.Add(2) + s2.Add(3) + s1.AddSet(s2) + if got := s1.Len(); got != 3 { + panic(fmt.Sprintf("(%v).Len() == %d, want 3", s1, got)) + } + s2.Add(1) + if !_Equal(s1, s2) { + panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2)) + } +} + +func TestSubSet() { + s1 := _Make[int]() + s1.Add(1) + s1.Add(2) + s2 := _Make[int]() + s2.Add(2) + s2.Add(3) + s1.SubSet(s2) + if got := s1.Len(); got != 1 { + panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got)) + } + if vals, want := s1.Values(), []int{1}; !_SliceEqual(vals, want) { + panic(fmt.Sprintf("after SubSet got %v, want %v", vals, want)) + } +} + +func TestIntersect() { + s1 := _Make[int]() + s1.Add(1) + s1.Add(2) + s2 := _Make[int]() + s2.Add(2) + s2.Add(3) + s1.Intersect(s2) + if got := s1.Len(); got != 1 { + panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got)) + } + if vals, want := s1.Values(), []int{2}; !_SliceEqual(vals, want) { + panic(fmt.Sprintf("after Intersect got %v, want %v", vals, want)) + } +} + +func TestIterate() { + s1 := _Make[int]() + s1.Add(1) + s1.Add(2) + s1.Add(3) + s1.Add(4) + tot := 0 + s1.Iterate(func(i int) { tot += i }) + if tot != 10 { + panic(fmt.Sprintf("total of %v == %d, want 10", s1, tot)) + } +} + +func TestFilter() { + s1 := _Make[int]() + s1.Add(1) + s1.Add(2) + s1.Add(3) + s1.Filter(func(v int) bool { return v%2 == 0 }) + if vals, want := s1.Values(), []int{2}; !_SliceEqual(vals, want) { + panic(fmt.Sprintf("after Filter got %v, want %v", vals, want)) + } + +} + +func main() { + TestSet() + TestEqual() + TestCopy() + TestAddSet() + TestSubSet() + TestIntersect() + TestIterate() + TestFilter() +} |