A ‘name’ (also known as a ‘symbol’) is a way to refer to
R objects by name (rather than the value of the object, if any, bound
to that name).
as.name and as.symbol are identical: they attempt to
coerce the argument to a name.
is.symbol and the identical is.name return TRUE
or FALSE depending on whether the argument is a name or not.
object to be coerced or tested.
For as.name and as.symbol, an R object of type
"symbol" (see typeof).
For is.name and is.symbol, a length-one logical vector
with value TRUE or FALSE.
Names are limited to 10,000 bytes (and were to 256 bytes in versions
of R before 2.13.0).
as.name first coerces its argument internally to a character
vector (so methods for as.character are not used). It then
takes the first element and provided it is not "", returns a
symbol of that name (and if the element is NA_character_, the
name is `NA`).
as.name is implemented as as.vector(x, "symbol"),
and hence will dispatch methods for the generic function as.vector.