methodUtilities           package:methods           R Documentation

Utility Functions for Methods and S-Plus Compatibility

Description:

     These are utilities, currently in the 'methods' package, that
     either provide some functionality needed by the package (e.g.,
     element matching by name), or add compatibility with S-Plus, or
     both.

Usage:

     functionBody(fun=sys.function(sys.parent()))

     allNames(x)

     getFunction(name, generic=TRUE, mustFind=TRUE, where)

     el(object, where)

     elNamed(x, name, mustFind=FALSE)

     formalArgs(def)

     Quote()

     showDefault(object, oldMethods = TRUE)

     initMethodDispatch(where = topenv(parent.frame()))

     methodSignatureMatrix(object, sigSlots = c("target", "defined"))

Summary of Functions:

     'allNames': the character vector of names (unlike 'names()', never
          returns 'NULL').

     'getFunction': find the object as a function.

     'elNamed': get the element of the vector corresponding to name. 
          Unlike the '[', '[[', and '$' operators, this function 
          requires 'name' to match the element name exactly (no partial
          matching).

     'formalArgs': Returns the names of the formal arguments of this
          function.

     'existsFunction': Is there a function of this name?  If 'generic'
          is 'FALSE', generic functions are not counted. 

     'findFunction': return all the indices of the search list on which
          a function definition for 'name' exists.  

          If 'generic' is 'FALSE', ignore generic functions.

     'showDefault': Utility, used to enable 'show' methods to be called
          by the automatic printing (via 'print.default').

          Argument 'oldMethods' controls whether old-style print
          methods are used for this object.  It is 'TRUE' by default if
          called directly, but 'FALSE' when called from the 'methods'
          package for automatic printing (to avoid potential
          recursion).

     'initMethodDispatch': Turn on the internal method dispatch code. 
          Called on attaching the package.  Also, if dispatch has been
          turned off (by calling '.isMethodsDispatchOn(FALSE)'-a very
          gutsy thing to do), calling this function should turn
          dispatch back on again.

     'methodSignatureMatrix': Returns a matrix with the contents of the
          specified slots as rows.  The slots should be named character
          strings of the same length.  Basically used to turn the
          signatures of a '"MethodDefinition"' objectg into a matrix
          for printing.

