R: Extract arguments from a call

lang_args {rlang} | R Documentation

## Extract arguments from a call

### Description

Extract arguments from a call

### Usage

    lang_args(lang)

    lang_args_names(lang)

### Arguments

`lang` | Can be a call (language object), a formula quoting a call in the right-hand side, or a frame object from which to extract the call expression.

### Value

A named list of arguments.

### See Also

`lang_tail()`, `fn_fmls()` and `fn_fmls_names()`

### Examples

    call <- quote(f(a, b))

    # Subsetting a call returns the arguments converted to a language
    # object:
    call[-1]

    # See also lang_tail() which returns the arguments without
    # conversion as the original pairlist:
    str(lang_tail(call))

    # On the other hand, lang_args() returns a regular list that is
    # often easier to work with:
    str(lang_args(call))

    # When the arguments are unnamed, a vector of empty strings is
    # supplied (rather than NULL):
    lang_args_names(call)

[Package rlang version 0.1.6 Index]