call {base} | R Documentation |
call(name, ...)
is.call(expr)
as.call(expr)
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.
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.
expression
, function
.
is.call(call) #-> FALSE: Functions are NOT calls
# set up a function call to round with argument 10.5
cl <- call("round",10.5)
cl
# such a call can also be evaluated.
eval(cl)# [1] 10