feat: add bounds(), make Range private back

ranges.v

@@ -3,9 +3,7 @@ module ranges
 import strconv
 import math.big
 
-@[noinit]
-pub struct Range[T] {
-pub:
+struct Range[T] {
 	start  T
 	end    T
 	step   T
@@ -31,6 +29,11 @@ pub fn (mut r Range[T]) reset() {
 	r.cur = r.start
 }
 
+// bounds returns the start, end and step values of range.
+pub fn (r Range[T]) bounds() (T, T, T) {
+	return r.start, r.end, r.step
+}
+
 // with_step returns copy of the range with new step value.
 pub fn (r Range[T]) with_step[T](step T) Range[T] {
 	return Range[T]{

ranges_test.v

@@ -179,3 +179,11 @@ fn test_range_new_with_step() {
 	}
 	assert result == [0, 2, 4]
 }
+
+fn test_range_bounds() {
+	r := ranges.range(0, 10, 2)
+	a, b, c := r.bounds()
+	assert a == 0
+	assert b == 10
+	assert c == 2
+}