language-class {methods} | R Documentation |
The virtual class "language"
and the specific
classes that extend it represent unevaluated objects, as produced for
example by the parser or by functions such as quote
.
### each of these classes corresponds to an unevaluated object
### in the S language.
### The class name can appear in method signatures,
### and in a few other contexts (such as some calls to as()).
"("
"<-"
"call"
"for"
"if"
"repeat"
"while"
"name"
"{"
### Each of the classes above extends the virtual class
"language"
"language"
is a virtual class; no objects may be created from
it.
Objects from the other classes can be generated by a call to
new(Class, ...)
, where Class
is the quoted class name, and
the ... arguments are either empty or a single object that is
from this class (or an extension).
signature(from = "ANY", to = "call")
. A method
exists for as(object, "call")
, calling as.call()
.