rlang (version 0.2.2)

call2: Create a call

Description

Language objects are (with symbols) one of the two types of symbolic objects in R. These symbolic objects form the backbone of expressions. They represent a value, unlike literal objects which are their own values. While symbols are directly bound to a value, language objects represent function calls, which is why they are commonly referred to as calls.

call2() creates a call from a function name (or a literal function to inline in the call) and a list of arguments.

Usage

call2(.fn, ..., .ns = NULL)

Arguments

.fn

Function to call. Must be a callable object: a string, symbol, call, or a function.

...

Arguments to the call either in or out of a list. These dots support tidy dots features.

.ns

Namespace with which to prefix .fn. Must be a string or symbol.

Life cycle

In rlang 0.2.0 lang() was soft-deprecated and renamed to call2().

In early versions of rlang calls were called "language" objects in order to follow the R type nomenclature as returned by base::typeof(). The goal was to avoid adding to the confusion between S modes and R types. With hindsight we find it is better to use more meaningful type names.

See Also

call_modify

Examples

# NOT RUN {
# fn can either be a string, a symbol or a call
call2("f", a = 1)
call2(quote(f), a = 1)
call2(quote(f()), a = 1)

#' Can supply arguments individually or in a list
call2(quote(f), a = 1, b = 2)
call2(quote(f), splice(list(a = 1, b = 2)))

# Creating namespaced calls:
call2("fun", arg = quote(baz), .ns = "mypkg")
# }