# lists

assert_eq(reversed([]), [])
assert_eq(reversed('a'.elems()), ['a'])
assert_eq(reversed('abc'.elems()), ['c', 'b', 'a'])
assert_eq(reversed('__test  '.elems()), [' ', ' ', 't', 's', 'e', 't', '_', '_'])
assert_eq(reversed('bbb'.elems()), ['b', 'b', 'b'])

---
reversed(None) ### got .* 'NoneType', want 'sequence'
---
reversed(1) ### got .* 'int', want 'sequence'
---
reversed({1: 3}) ### got .* 'dict', want 'sequence'
---

x = ['a', 'b']
y = reversed(x)
y.append('c')
assert_eq(y, ['b', 'a', 'c'])
assert_eq(x, ['a', 'b'])

def reverse_equivalence(inp):
  assert_eq(reversed(inp), inp[::-1])
  assert_eq(reversed(reversed(inp)), inp)

reverse_equivalence([])
reverse_equivalence([1])
reverse_equivalence(["a", "b"])