deparseOpts               package:base               R Documentation

Options for Expression Deparsing

Description:

     Process the deparsing options for 'deparse', 'dput' and 'dump'.

Usage:

     .deparseOpts(control)

Arguments:

 control: character vector of deparsing options.

Details:

     This is called by 'deparse', 'dput' and 'dump' to process their
     'control' argument.

     The 'control' argument is a vector containing zero or more of the
     following strings.  Partial string matching is used.

     'keepInteger' Either surround integer vectors by 'as.integer()' or
          use suffix 'L', so they are not converted to type double when
          parsed.  This includes making sure that integer 'NA's are
          preserved (via 'NA_integer_' if there are no non-'NA' values
          in the vector, unless '"S_compatible"' is set).

     'quoteExpressions' Surround expressions with 'quote()', so they
          are not evaluated when re-parsed.

     'showAttributes' If the object has attributes (other than a
          'source' attribute), use 'structure()' to display them as
          well as the object value.  This is the default for 'deparse'
          and 'dput'.

     'useSource' If the object has a 'source' attribute, display that
          instead of deparsing the object.  Currently only applies to
          function definitions.

     'warnIncomplete' Some exotic objects such as environments,
          external pointers, etc. can not be deparsed properly.  This
          option causes a warning to be issued if any of those may give
          problems.

          Also, the parser in R < 2.7.0 would only accept strings of up
          to 8192 bytes, and this option gives a warning for longer
          strings.

     'keepNA' Integer, real and character 'NA's are surrounded by
          coercion where necessary to ensure that they are parsed to
          the same type.

     'all' An abbreviated way to specify all of the options listed
          above.  This is the default for 'dump', and the options used
          by 'edit' (which are fixed).

     'delayPromises' Deparse promises in the form <promise: expression>
          rather than evaluating them.  The value and the environment
          of the promise will not be shown and the deparsed code cannot
          be sourced.

     'S_compatible' Make deparsing as far as possible compatible with S
          and R < 2.5.0. For compatibility with S, integer values of
          double vectors are deparsed with a trailing decimal point.


     For the most readable (but perhaps incomplete) display, use
     'control = NULL'. This displays the object's value, but not its
     attributes.  The default in 'deparse' is to display the attributes
     as well, but not to use any of the other options to make the
     result parseable.  ('dput' and 'dump' do use more default options,
     and printing of functions without sources uses 'c("keepInteger",
     "keepNA")'.)

     Using 'control = "all"' comes closest to making 'deparse()' an
     inverse of 'parse()'.  However, not all objects are deparse-able
     even with this option.  A warning will be issued if the function
     recognizes that it is being asked to do the impossible.

Value:

     A numerical value corresponding to the options selected.

