Try to access element and return some default value if not found.
In contrast to [at2()], this function provides a less stricter element
access, that is, it remains valid even if peeked elements don't exist.
peek_at2(x, index, default = NULL)
# S3 method for Container
peek_at2(x, index, default = NULL)
# S3 method for dict.table
peek_at2(x, index, default = NULL)an R object of the respective class.
character name or numeric position of the sought value.
value to be returned if peeked value does not exist.
For Container, returns the value at the given index or (if not
found) the given default value.
For dict.table, returns the column named index if it exist
otherwise the given default value. If the default length does not match
the number of rows, it is recycled accordingly and a warning is given,
unless the default value has a length of 1, in which case recycling is
done silently.
at2() for strict element extraction
# Container
co = container(a = 1, 2, b = 3, 4)
peek_at2(co, 1)
#> [1] 1
peek_at2(co, "a")
#> [1] 1
peek_at2(co, "x")
#> NULL
peek_at2(co, "x", default = 0)
#> [1] 0
# Dict
d = dict(a = 1, b = 1:3)
peek_at2(d, "b")
#> [1] 1 2 3
peek_at2(d, "x")
#> NULL
peek_at2(d, "x", default = 4:7)
#> [1] 4 5 6 7
# dict.table
dit = dict.table(a = 1:3, b = 4:6)
peek_at2(dit, "a")
#> [1] 1 2 3
peek_at2(dit, 1)
#> [1] 1 2 3
peek_at2(dit, 3)
#> NULL
peek_at2(dit, 3, default = 9)
#> [1] 9 9 9
peek_at2(dit, "x")
#> NULL
peek_at2(dit, "x", default = 0)
#> [1] 0 0 0