Add IndexedSet (#31)

gofp/indexed_set.go

@@ -0,0 +1,42 @@
+package gofp
+
+// IndexedSet works like a map but it keeps the order.
+type IndexedSet[Key, Value comparable] struct {
+	m map[Key]Value
+	i []Key
+}
+
+// Add adds a new element to the set.
+func (i *IndexedSet[Key, Value]) Add(k Key, v Value) {
+	if i.m == nil {
+		i.m = make(map[Key]Value)
+	}
+
+	if !i.Has(k) {
+		i.i = append(i.i, k)
+	}
+
+	i.m[k] = v
+}
+
+// Get returns a the value assigned to the provided key.
+func (i *IndexedSet[Key, Value]) Get(k Key) (Value, bool) {
+	v, ok := i.m[k]
+	return v, ok
+}
+
+// Has verifies if an element exists in the set.
+func (i *IndexedSet[Key, Value]) Has(k Key) bool {
+	_, ok := i.m[k]
+	return ok
+}
+
+// Keys returns the keys in order.
+func (i *IndexedSet[Key, Value]) Keys() []Key {
+	return i.i
+}
+
+// Map returns the map.
+func (i *IndexedSet[Key, Value]) Map() map[Key]Value {
+	return i.m
+}

gofp/indexed_set_test.go

@@ -0,0 +1,72 @@
+package gofp_test
+
+import (
+	"testing"
+
+	"github.com/msales/gox/gofp"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInitializeIndexedSet(t *testing.T) {
+	testCases := []struct {
+		name     string
+		initFunc func() gofp.IndexedSet[int, int]
+	}{
+		{
+			name: "Initialize with empty value",
+			initFunc: func() gofp.IndexedSet[int, int] {
+				return gofp.IndexedSet[int, int]{}
+			},
+		},
+		{
+			name: "Initialize with var",
+			initFunc: func() gofp.IndexedSet[int, int] {
+				var val gofp.IndexedSet[int, int]
+				return val
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			set := tc.initFunc()
+
+			assert.NotPanics(t, func() { set.Add(1, 1) })
+		})
+	}
+}
+
+func Test_IndexedSet_Has(t *testing.T) {
+	var intSet gofp.IndexedSet[int, int]
+	intSet.Add(1, 2)
+	intSet.Add(2, 1)
+
+	assert.True(t, intSet.Has(1))
+
+	type simpleStruct struct {
+		Foo int
+		Bar string
+	}
+
+	var simpleStructSet gofp.IndexedSet[simpleStruct, int]
+	simpleStructSet.Add(simpleStruct{Foo: 1, Bar: "foo"}, 1)
+	simpleStructSet.Add(simpleStruct{Foo: 2, Bar: "baz"}, 1)
+
+	assert.True(t, simpleStructSet.Has(simpleStruct{Foo: 1, Bar: "foo"}))
+}
+
+func Test_IndexedSet_Add(t *testing.T) {
+	var intSet gofp.IndexedSet[int, int]
+	// add unique elements
+	intSet.Add(1, 2)
+
+	val, ok := intSet.Get(1)
+	assert.True(t, ok)
+	assert.Equal(t, 2, val)
+
+	intSet.Add(2, 3)
+
+	val, ok = intSet.Get(2)
+	assert.True(t, ok)
+	assert.Equal(t, 3, val)
+}