Added some more find functions

moslice/filter.go

@@ -16,3 +16,22 @@ func Filter[T any](ts []T, predicate func(t T) bool) []T {
 	}
 	return filteredTs
 }
+
+// FilterMap returns a mapped slice containing all the elements of ts for which the passed in
+// predicate returns true.  If no items match the predicate, the function will return
+// an empty slice.  If ts is nil, the function will also return nil.
+func FilterMap[T, U any](ts []T, predicate func(t T) (U, bool)) []U {
+	if ts == nil {
+		return nil
+	}
+
+	filteredUs := make([]U, 0)
+	for _, t := range ts {
+		u, ok := predicate(t)
+		if !ok {
+			continue
+		}
+		filteredUs = append(filteredUs, u)
+	}
+	return filteredUs
+}

moslice/filter_test.go

@@ -1,10 +1,12 @@
 package moslice_test
 
 import (
-	"lmika.dev/pkg/modash/moslice"
+	"fmt"
 	"strings"
 	"testing"
 
+	"lmika.dev/pkg/modash/moslice"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -27,3 +29,23 @@ func TestFilter(t *testing.T) {
 		assert.Equal(t, []int{}, moslice.Filter([]int{}, func(x int) bool { return x%2 == 0 }))
 	})
 }
+
+func TestFilterMap(t *testing.T) {
+	var (
+		ints = []int{1, 2, 3, 4, 5}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should filter items matching the predicate", func(t *testing.T) {
+		assert.Equal(t, []string{"2", "4"}, moslice.FilterMap(ints, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+		assert.Equal(t, []int{3, 3}, moslice.FilterMap(strs, func(x string) (int, bool) { return len(x), strings.Contains(x, "b") }))
+	})
+
+	t.Run("should moslice nil if the passed in slice is nil", func(t *testing.T) {
+		assert.Nil(t, moslice.FilterMap(nil, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+	})
+
+	t.Run("should return empty slice if the passed in slice is empty slice", func(t *testing.T) {
+		assert.Equal(t, []string{}, moslice.FilterMap([]int{}, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+	})
+}

moslice/find.go

@@ -20,6 +20,16 @@ func FirstWhere[T any](ts []T, predicate func(t T) bool) T {
 	return zeroT
 }
 
+// FirstIndexWhere returns the index of the first element in the slice that satisfies the predicate. An empty slice will return -1
+func FirstIndexWhere[T any](ts []T, predicate func(t T) bool) int {
+	for i, t := range ts {
+		if predicate(t) {
+			return i
+		}
+	}
+	return -1
+}
+
 func FindWhere[T any](ts []T, predicate func(t T) bool) (T, bool) {
 	var zeroT T
 
@@ -41,3 +51,26 @@ func FindWithIndexWhere[T any](ts []T, predicate func(t T) bool) (T, int, bool)
 	}
 	return zeroT, 0, false
 }
+
+// AnyWhere returns true if any element in the slice satisfies the predicate. An empty slice will return false
+func AnyWhere[T any](ts []T, predicate func(t T) bool) bool {
+	for _, t := range ts {
+		if predicate(t) {
+			return true
+		}
+	}
+	return false
+}
+
+// AllWhere returns true if all the element in the slice satisfies the predicate. An empty slice will return false
+func AllWhere[T any](ts []T, predicate func(t T) bool) bool {
+	if len(ts) == 0 {
+		return false
+	}
+	for _, t := range ts {
+		if !predicate(t) {
+			return false
+		}
+	}
+	return true
+}

moslice/find_test.go

@@ -1,9 +1,11 @@
 package moslice_test
 
 import (
-	"lmika.dev/pkg/modash/moslice"
+	"strings"
 	"testing"
 
+	"lmika.dev/pkg/modash/moslice"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -23,3 +25,117 @@ func TestContains(t *testing.T) {
 		assert.False(t, moslice.Contains(strs, "bla"))
 	})
 }
+
+func TestFirstWhere(t *testing.T) {
+	var (
+		ints = []int{1, 2, 3, 4, 5}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should return the first element that satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, 2, moslice.FirstWhere(ints, func(x int) bool { return x%2 == 0 }))
+		assert.Equal(t, "bar", moslice.FirstWhere(strs, func(x string) bool { return strings.HasPrefix(x, "b") }))
+	})
+
+	t.Run("should return the element if the first element satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, 1, moslice.FirstWhere(ints, func(x int) bool { return x%2 == 1 }))
+		assert.Equal(t, "foo", moslice.FirstWhere(strs, func(x string) bool { return strings.HasPrefix(x, "f") }))
+	})
+
+	t.Run("should return the zero value if no element satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, 0, moslice.FirstWhere(ints, func(x int) bool { return x > 10 }))
+		assert.Equal(t, "", moslice.FirstWhere(strs, func(x string) bool { return strings.HasPrefix(x, "z") }))
+	})
+
+	t.Run("should return the zero value if the passed in slice is empty", func(t *testing.T) {
+		assert.Equal(t, 0, moslice.FirstWhere([]int{}, func(x int) bool { return true }))
+	})
+
+	t.Run("should return the zero value if the passed in slice is nil", func(t *testing.T) {
+		assert.Equal(t, 0, moslice.FirstWhere(nil, func(x int) bool { return true }))
+	})
+}
+
+func TestFirstIndexWhere(t *testing.T) {
+	var (
+		ints = []int{1, 2, 3, 4, 5}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should return the index of the first element that satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, 1, moslice.FirstIndexWhere(ints, func(x int) bool { return x%2 == 0 }))
+		assert.Equal(t, 1, moslice.FirstIndexWhere(strs, func(x string) bool { return strings.HasPrefix(x, "b") }))
+	})
+
+	t.Run("should return 0 if the first element satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, 0, moslice.FirstIndexWhere(ints, func(x int) bool { return x%2 == 1 }))
+		assert.Equal(t, 0, moslice.FirstIndexWhere(strs, func(x string) bool { return strings.HasPrefix(x, "f") }))
+	})
+
+	t.Run("should return -1 if no element satisfies the predicate", func(t *testing.T) {
+		assert.Equal(t, -1, moslice.FirstIndexWhere(ints, func(x int) bool { return x > 10 }))
+		assert.Equal(t, -1, moslice.FirstIndexWhere(strs, func(x string) bool { return strings.HasPrefix(x, "z") }))
+	})
+
+	t.Run("should return -1 if the passed in slice is empty", func(t *testing.T) {
+		assert.Equal(t, -1, moslice.FirstIndexWhere([]int{}, func(x int) bool { return true }))
+	})
+
+	t.Run("should return -1 if the passed in slice is nil", func(t *testing.T) {
+		assert.Equal(t, -1, moslice.FirstIndexWhere(nil, func(x int) bool { return true }))
+	})
+}
+
+func TestAnyWhere(t *testing.T) {
+	var (
+		ints = []int{1, 2, 3, 4, 5}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should return true if any element satisfies the predicate", func(t *testing.T) {
+		assert.True(t, moslice.AnyWhere(ints, func(x int) bool { return x%2 == 0 }))
+		assert.True(t, moslice.AnyWhere(strs, func(x string) bool { return strings.HasPrefix(x, "ba") }))
+	})
+
+	t.Run("should return false if no element satisfies the predicate", func(t *testing.T) {
+		assert.False(t, moslice.AnyWhere(ints, func(x int) bool { return x > 10 }))
+		assert.False(t, moslice.AnyWhere(strs, func(x string) bool { return strings.HasPrefix(x, "z") }))
+	})
+
+	t.Run("should return false if the passed in slice is empty", func(t *testing.T) {
+		assert.False(t, moslice.AnyWhere([]int{}, func(x int) bool { return true }))
+	})
+
+	t.Run("should return false if the passed in slice is nil", func(t *testing.T) {
+		assert.False(t, moslice.AnyWhere(nil, func(x int) bool { return true }))
+	})
+}
+
+func TestAllWhere(t *testing.T) {
+	var (
+		ints = []int{2, 4, 6}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should return true if all elements satisfy the predicate", func(t *testing.T) {
+		assert.True(t, moslice.AllWhere(ints, func(x int) bool { return x%2 == 0 }))
+		assert.True(t, moslice.AllWhere(strs, func(x string) bool { return len(x) == 3 }))
+	})
+
+	t.Run("should return false if some elements do not satisfy the predicate", func(t *testing.T) {
+		assert.False(t, moslice.AllWhere(ints, func(x int) bool { return x > 3 }))
+		assert.False(t, moslice.AllWhere(strs, func(x string) bool { return strings.HasPrefix(x, "b") }))
+	})
+
+	t.Run("should return false if no elements satisfy the predicate", func(t *testing.T) {
+		assert.False(t, moslice.AllWhere(ints, func(x int) bool { return x > 10 }))
+	})
+
+	t.Run("should return false if the passed in slice is empty", func(t *testing.T) {
+		assert.False(t, moslice.AllWhere([]int{}, func(x int) bool { return true }))
+	})
+
+	t.Run("should return false if the passed in slice is nil", func(t *testing.T) {
+		assert.False(t, moslice.AllWhere(nil, func(x int) bool { return true }))
+	})
+}