Is object a call?

These functions are deprecated, please use is_call() and its n argument instead.

is_lang(x, name = NULL, n = NULL, ns = NULL)

is_unary_lang(x, name = NULL, ns = NULL)

is_binary_lang(x, name = NULL, ns = NULL)

quo_is_lang(quo)

Arguments

x	An object to test. If a formula, the right-hand side is extracted.
name	An optional name that the call should match. It is passed to sym() before matching. This argument is vectorised and you can supply a vector of names to match. In this case, is_call() returns TRUE if at least one name matches.
n	An optional number of arguments that the call should match.
ns	The namespace of the call. If NULL, the namespace doesn't participate in the pattern-matching. If an empty string "" and x is a namespaced call, is_call() returns FALSE. If any other string, is_call() checks that x is namespaced within ns. Can be a character vector of namespaces, in which case the call has to match at least one of them, otherwise is_call() returns FALSE.
quo	A quosure to test.