iotools (version 0.3-1)

as.output: Character Output

Description

Create objects of class output.

Usage

as.output(x, ...)

Arguments

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.

Value

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.

Details

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.

Examples

# NOT RUN {
  m = matrix(sample(letters), ncol=2)
  as.output(m)

  df = data.frame(a = sample(letters), b = runif(26), c = sample(state.abb,26))
  str(as.output(df))

  as.output(df, con=iotools.stdout)
# }