is.language {base} | R Documentation |
is.language
returns TRUE
if x
is either a
variable name
, a call
, or an
expression
.
is.language(x)
ll <- list(a = expression(x^2 - 2*x + 1), b = as.name("Jim"), c = as.expression(exp(1)), d = call("sin", pi)) sapply(ll, typeof) sapply(ll, mode) sapply(ll, is.language)# all TRUE