feat: add Range function

mathutil/mathutil.go

@@ -183,3 +183,20 @@ func Average[T constraints.Integer | constraints.Float](numbers ...T) T {
 	}
 	return sum / n
 }
+
+// Range creates a slice of numbers from start with specified count, element step is 1.
+// Play: todo
+func Range[T constraints.Integer | constraints.Float](start T, count int) []T {
+	size := count
+	if count < 0 {
+		size = -count
+	}
+
+	result := make([]T, size)
+
+	for i, j := 0, start; i < size; i, j = i+1, j+1 {
+		result[i] = j
+	}
+
+	return result
+}