is.language

R Base 3.6.2

is.language returns TRUE if x is a variable name, a call, or an expression.

Syntax

is.language(x)

Arguments

Parameter	Description
`x`	object to be tested.

Examples

Example

# NOT RUN {
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)
stopifnot(sapply(ll, is.language))
# }