

   FFuunnccttiioonn CCaallllss

        call(name, ...)

        is.call(expr)
        as.call(expr)

   VVaalluuee::

        An unevaluated function call, that is, an unevaluated
        expression which consists of the named function applied
        to the given arguments (`name' must be a quoted string
        which gives the name of a function to be called).

        `is.call' is used to determine whether `expr' is a
        call.

        It is not possible to coerce objects to mode call
        (objects either are calls or they are not calls).
        `as.call' returns its argument if it is a call and oth-
        erwise terminates with an error message.

   SSeeee AAllssoo::

        `do.call' for calling a function by name and argument
        list; `Recall' for recursive calling of functions;
        further `is.language', `expression', `function'.

   EExxaammpplleess::

        is.call(call) #-> FALSE: Functions are NOT calls

        # set up a function call to round with argument 10.5
        cl <- call("round",10.5)
        is.call(cl)# TRUE
        cl
        # such a call can also be evaluated.
        eval(cl)# [1] 10

