Keys+Values: accept multiple maps (vaargs) - Adding UniqKeys+UniqValues

README.md

@@ -125,9 +125,11 @@ Supported helpers for slices:
 Supported helpers for maps:
 
 - [Keys](#keys)
-- [HasKey](#HasKey)
+- [UniqKeys](#uniqkeys)
+- [HasKey](#haskey)
 - [ValueOr](#valueor)
 - [Values](#values)
+- [UniqValues](#uniqvalues)
 - [PickBy](#pickby)
 - [PickByKeys](#pickbykeys)
 - [PickByValues](#pickbyvalues)
@@ -1040,15 +1042,37 @@ result = lo.Splice([]string{"a", "b"}, 42, "1", "2")
 
 ### Keys
 
-Creates an array of the map keys.
+Creates a slice of the map keys.
+
+Use the UniqKeys variant to deduplicate common keys.
 
 ```go
 keys := lo.Keys(map[string]int{"foo": 1, "bar": 2})
 // []string{"foo", "bar"}
+
+keys := lo.Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+// []string{"foo", "bar", "baz"}
+
+keys := lo.Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 3})
+// []string{"foo", "bar", "bar"}
 ```
 
 [[play](https://go.dev/play/p/Uu11fHASqrU)]
 
+### UniqKeys
+
+Creates an array of unique map keys. 
+
+```go
+keys := lo.Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+// []string{"foo", "bar", "baz"}
+
+keys := lo.Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 3})
+// []string{"foo", "bar"}
+```
+
+[[play](https://go.dev/play/p/TPKAb6ILdHk)]
+
 ### HasKey
 
 Returns whether the given key exists.
@@ -1067,13 +1091,38 @@ exists := lo.HasKey(map[string]int{"foo": 1, "bar": 2}, "baz")
 
 Creates an array of the map values.
 
+Use the UniqValues variant to deduplicate common values.
+
 ```go
 values := lo.Values(map[string]int{"foo": 1, "bar": 2})
 // []int{1, 2}
+
+values := lo.Values(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+// []int{1, 2, 3}
+
+values := lo.Values(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 2})
+// []int{1, 2, 2}
 ```
 
 [[play](https://go.dev/play/p/nnRTQkzQfF6)]
 
+### UniqValues
+
+Creates an array of unique map values.
+
+```go
+values := lo.UniqValues(map[string]int{"foo": 1, "bar": 2})
+// []int{1, 2}
+
+values := lo.UniqValues(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+// []int{1, 2, 3}
+
+values := lo.UniqValues(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 2})
+// []int{1, 2}
+```
+
+[[play](https://go.dev/play/p/nf6bXMh7rM3)]
+
 ### ValueOr
 
 Returns the value of the given key or the fallback value if the key is not present.

map.go

@@ -2,11 +2,32 @@ package lo
 
 // Keys creates an array of the map keys.
 // Play: https://go.dev/play/p/Uu11fHASqrU
-func Keys[K comparable, V any](in map[K]V) []K {
-	result := make([]K, 0, len(in))
+func Keys[K comparable, V any](in ...map[K]V) []K {
+	result := make([]K, 0)
 
-	for k := range in {
-		result = append(result, k)
+	for i := range in {
+		for k := range in[i] {
+			result = append(result, k)
+		}
+	}
+
+	return result
+}
+
+// UniqKeys creates an array of unique keys in the map.
+// Play: https://go.dev/play/p/TPKAb6ILdHk
+func UniqKeys[K comparable, V any](in ...map[K]V) []K {
+	seen := make(map[K]struct{})
+	result := make([]K, 0)
+
+	for i := range in {
+		for k := range in[i] {
+			if _, exists := seen[k]; exists {
+				continue
+			}
+			seen[k] = struct{}{}
+			result = append(result, k)
+		}
 	}
 
 	return result
@@ -21,11 +42,33 @@ func HasKey[K comparable, V any](in map[K]V, key K) bool {
 
 // Values creates an array of the map values.
 // Play: https://go.dev/play/p/nnRTQkzQfF6
-func Values[K comparable, V any](in map[K]V) []V {
+func Values[K comparable, V any](in ...map[K]V) []V {
 	result := make([]V, 0, len(in))
 
-	for k := range in {
-		result = append(result, in[k])
+	for i := range in {
+		for k := range in[i] {
+			result = append(result, in[i][k])
+		}
+	}
+
+	return result
+}
+
+// UniqValues creates an array of unique values in the map.
+// Play: https://go.dev/play/p/nf6bXMh7rM3
+func UniqValues[K comparable, V comparable](in ...map[K]V) []V {
+	seen := make(map[V]struct{})
+	result := make([]V, 0)
+
+	for i := range in {
+		for k := range in[i] {
+			val := in[i][k]
+			if _, exists := seen[val]; exists {
+				continue
+			}
+			seen[val] = struct{}{}
+			result = append(result, val)
+		}
 	}
 
 	return result

map_example_test.go

@@ -9,20 +9,44 @@ import (
 
 func ExampleKeys() {
 	kv := map[string]int{"foo": 1, "bar": 2}
+	kv2 := map[string]int{"baz": 3}
 
-	result := Keys(kv)
+	result := Keys(kv, kv2)
+	sort.Strings(result)
+	fmt.Printf("%v", result)
+	// Output: [bar baz foo]
 
-	sort.StringSlice(result).Sort()
+}
+
+func ExampleUniqKeys() {
+	kv := map[string]int{"foo": 1, "bar": 2}
+	kv2 := map[string]int{"bar": 3}
+
+	result := UniqKeys(kv, kv2)
+	sort.Strings(result)
 	fmt.Printf("%v", result)
 	// Output: [bar foo]
+
 }
 
 func ExampleValues() {
 	kv := map[string]int{"foo": 1, "bar": 2}
+	kv2 := map[string]int{"baz": 3}
+
+	result := Values(kv, kv2)
+
+	sort.Ints(result)
+	fmt.Printf("%v", result)
+	// Output: [1 2 3]
+}
+
+func ExampleUniqValues() {
+	kv := map[string]int{"foo": 1, "bar": 2}
+	kv2 := map[string]int{"baz": 2}
 
-	result := Values(kv)
+	result := UniqValues(kv, kv2)
 
-	sort.IntSlice(result).Sort()
+	sort.Ints(result)
 	fmt.Printf("%v", result)
 	// Output: [1 2]
 }

map_test.go

@@ -15,8 +15,44 @@ func TestKeys(t *testing.T) {
 
 	r1 := Keys(map[string]int{"foo": 1, "bar": 2})
 	sort.Strings(r1)
+	is.Equal(r1, []string{"bar", "foo"})
+
+	r2 := Keys(map[string]int{})
+	is.Empty(r2)
+
+	r3 := Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+	sort.Strings(r3)
+	is.Equal(r3, []string{"bar", "baz", "foo"})
+
+	r4 := Keys[string, int]()
+	is.Equal(r4, []string{})
 
+	r5 := Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 3})
+	sort.Strings(r5)
+	is.Equal(r5, []string{"bar", "bar", "foo"})
+}
+
+func TestUniqKeys(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	r1 := UniqKeys(map[string]int{"foo": 1, "bar": 2})
+	sort.Strings(r1)
 	is.Equal(r1, []string{"bar", "foo"})
+
+	r2 := UniqKeys(map[string]int{})
+	is.Empty(r2)
+
+	r3 := UniqKeys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+	sort.Strings(r3)
+	is.Equal(r3, []string{"bar", "baz", "foo"})
+
+	r4 := UniqKeys[string, int]()
+	is.Equal(r4, []string{})
+
+	r5 := UniqKeys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"foo": 1, "bar": 3})
+	sort.Strings(r5)
+	is.Equal(r5, []string{"bar", "foo"})
 }
 
 func TestHasKey(t *testing.T) {
@@ -36,8 +72,48 @@ func TestValues(t *testing.T) {
 
 	r1 := Values(map[string]int{"foo": 1, "bar": 2})
 	sort.Ints(r1)
+	is.Equal(r1, []int{1, 2})
 
+	r2 := Values(map[string]int{})
+	is.Empty(r2)
+
+	r3 := Values(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+	sort.Ints(r3)
+	is.Equal(r3, []int{1, 2, 3})
+
+	r4 := Values[string, int]()
+	is.Equal(r4, []int{})
+
+	r5 := Values(map[string]int{"foo": 1, "bar": 2}, map[string]int{"foo": 1, "bar": 3})
+	sort.Ints(r5)
+	is.Equal(r5, []int{1, 1, 2, 3})
+}
+
+func TestUniqValues(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	r1 := UniqValues(map[string]int{"foo": 1, "bar": 2})
+	sort.Ints(r1)
 	is.Equal(r1, []int{1, 2})
+
+	r2 := UniqValues(map[string]int{})
+	is.Empty(r2)
+
+	r3 := UniqValues(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})
+	sort.Ints(r3)
+	is.Equal(r3, []int{1, 2, 3})
+
+	r4 := UniqValues[string, int]()
+	is.Equal(r4, []int{})
+
+	r5 := UniqValues(map[string]int{"foo": 1, "bar": 2}, map[string]int{"foo": 1, "bar": 3})
+	sort.Ints(r5)
+	is.Equal(r5, []int{1, 2, 3})
+
+	r6 := UniqValues(map[string]int{"foo": 1, "bar": 1}, map[string]int{"foo": 1, "bar": 3})
+	sort.Ints(r6)
+	is.Equal(r6, []int{1, 3})
 }
 
 func TestValueOr(t *testing.T) {