is_lang: Is object a call?
In rlang: Functions for Base Types and Core R and 'Tidyverse' Features

is_lang

R Documentation

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)

`x`	An object to test. Formulas and quosures are treated literally.
`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`.