feat: reduce

reduce.go

@@ -0,0 +1,8 @@
+package underscore
+
+func Reduce[T, P any](values []T, predicate func(T, P) P, acc P) P {
+	for _, v := range values {
+		acc = predicate(v, acc)
+	}
+	return acc
+}

reduce_test.go

@@ -0,0 +1,19 @@
+package underscore_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	u "github.com/rjNemo/underscore"
+)
+
+func TestReduce(t *testing.T) {
+	nums := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	reducer := func(n, acc int) int {
+		return n + acc
+	}
+	want := 45
+
+	assert.Equal(t, want, u.Reduce(nums, reducer, 0))
+}