rlang (version 0.1)

lang_args: 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

# NOT RUN {
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)
# }