Extracts the value of a Container at the given index. If the index is invalid, an error is signaled. If given as a string, the element matching the name is returned. If there are two or more identical names, the value of the first match (i.e. leftmost element) is returned. Extract value at index. If index is invalid or not found, an error is signaled. If given as a string, the element matching the name is returned. If there are two or more identical names, the value of the first match (i.e. leftmost element) is returned.
at2(x, ...)
# S3 method for Container
at2(x, index, ...)
# S3 method for dict.table
at2(x, index, ...)an R object of the respective class.
other arguments passed to or from methods.
character name or numeric position of the sought value.
For Container, returns the value at the given index.
For dict.table, returns the column at the given index or signals
an error if not found.
peek_at2() for less strict extraction
# Container
co = container(a = 1, 2, b = 3, 4)
at2(co, 1)
#> [1] 1
at2(co, "a")
#> [1] 1
at2(co, 2)
#> [1] 2
try(at2(co, "x")) # index 'x' not found
#> Error : index 'x' not found
try(at2(co, 5)) # index 5 exceeds length of Container
#> Error : index 5 exceeds length of Container, which is 4
# Dict
d = dict(a = 1, b = 3)
at2(d, 1)
#> [1] 1
at2(d, "a")
#> [1] 1
at2(d, 2)
#> [1] 3
try(at2(d, "x")) # index 'x' not found
#> Error : index 'x' not found
try(at2(d, 5)) # index 5 exceeds length of Dict
#> Error : index 5 exceeds length of Dict, which is 2
# dict.table
dit = dict.table(a = 1:3, b = 4:6)
at2(dit, 1)
#> [1] 1 2 3
at2(dit, "a")
#> [1] 1 2 3
at2(dit, 2)
#> [1] 4 5 6
try(at2(dit, "x")) # index 'x' not found
#> Error : index 'x' not found
try(at2(dit, 5)) # index 5 exceeds length of dict.table
#> Error : index 5 exceeds length of dict.table, which is 2