

   LLiissttss

        list(...)
        as.list(x)
        is.list(x)
        alist(...)

   DDeessccrriippttiioonn::

        The arguments to `list' are of the form `value' or
        `tag=value'.  The function returns a list composed of
        its arguments with each value either tagged or
        untagged, depending on how the argument was specified.

        `alist' is like `list', except in the handling of
        tagged arguments with no value. These are handled as if
        they described function arguments with no default (cf.
        `formals'), whereas `list' simply ignores them.

        `as.list' attempts to coerce its argument to list type.
        For functions, this returns the concatenation of the
        list of formals arguments and the function body. For
        expressions, the list of constituent calls is returned.

        `is.list' returns `TRUE' if its argument is a list and
        `FALSE' otherwise.

        To create an empty list, it is necessary to use the
        function `vector' with a `mode' of `"list"'.

   SSeeee AAllssoo::

        `vector(., mode="list")', `c', for concatenation; `for-
        mals'.

   EExxaammpplleess::

        data(cars)
        # create a plotting structure
        pts <- list(x=cars[,1], y=cars[,2])
        plot(pts)

        # Argument lists
        f <- function()x
        formals(f) <- alist(x=, y=2, ...=) # Note the spec. of a "..." argument
        f

