container: Extending Base 'R' Lists

ee = expect_equal

# ------------------
# at2.Container
# ------------------
co = container(a = 1, 2, b = 3, 4)
ee(at2(co, 1), 1)
ee(at2(co, 2), 2)
ee(at2(co, "a"), 1)
expect_error(at2(container(), 1),
             "index 1 exceeds length of Container, which is 0")
expect_error(at2(co), "'index' is missing")
expect_error(at2(co, 1:2), "index must be of length 1")
expect_error(at2(co, "x"), "index 'x' not found")

# -------------
# at2.Dict
# -------------
d = dict(a = 1, b = 2)
ee(at2(d, 1), 1)
ee(at2(d, 2), 2)
ee(at2(d, "a"), 1)
expect_error(at2(dict(), 1), "index 1 exceeds length of Dict, which is 0")
expect_error(at2(d), "'index' is missing")
expect_error(at2(d, 1:2), "index must be of length 1")
expect_error(at2(d, "x"), "index 'x' not found")


# -------------------
# at2.dict.table
# -------------------
dit = dict.table(a = 1:3, b = 4:6)
ee(at2(dit, "a"), 1:3)
ee(at2(dit, 1), 1:3)
expect_error(at2(dict.table(), 1),
             "index 1 exceeds length of dict.table, which is 0")
expect_error(at2(dit), "'index' is missing")
expect_error(at2(dit, 1:2), "index must be of length 1")
expect_error(at2(dit, "x"), "index 'x' not found")