asoutput.RdCreate objects of class output.
as.output(x, ...)object to be converted to an instance of output.
optional arguments to be passed to implementing methods
of as.output. Most methods support the following arguments:
sep string, column/value separator, nsep string, key
separator, keys either a logical (if FALSE names/row
names are suppressed) or a character vector with overriding
keys. The default for keys typically varies by class or is
auto-detected (e.g., named vectors user names as keys,
data.frames use row names if they are non-automatic
etc.). All methods also support con argument which pushes
the output into a connection instead of generating an output object
- so as.output(x, con=...) is thus not a coersion but used
only for its side-effect.
Note that con also supports special values
iotools.stdout, iotools.stderr and
iotools.fd(fd) which write directly into the corresponding
streams instead of using theconnection API.
as.output is generic, and methods can be written to support
new classes. The output is meant to be a raw vector suitable for
writing to the disk or sending over a connection.
if con is set to a connection then the result is NULL
and the method is used for its side-effect, otherwise the result is a raw vector.
Side note: we cannot create a formal type of output, because
writeBin does is.vector() check which doesn't dispatch
and prevents anything with a class to be written.
m = matrix(sample(letters), ncol=2)
as.output(m)
#> [1] 75 7c 63 0a 7a 7c 65 0a 78 7c 66 0a 6a 7c 6e 0a 72 7c 64 0a 79 7c 67 0a 76
#> [26] 7c 62 0a 6d 7c 68 0a 74 7c 73 0a 6f 7c 70 0a 77 7c 69 0a 6b 7c 71 0a 61 7c
#> [51] 6c 0a
df = data.frame(a = sample(letters), b = runif(26), c = sample(state.abb,26))
str(as.output(df))
#> raw [1:596] 6b 7c 30 2e ...
as.output(df, con=iotools.stdout)
#> NULL