call(name, ...) is.call(expr) as.call(expr)
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.
We don't differentiate between expressions and function calls.
So is.call
is the same as is.expression
.
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
otherwise terminated with an error message.