deprecated_quo_is_present: 'lifecycle::is_present' for enquosed deprecated NSE arg

In cmu-delphi/epiprocess: Tools for basic signal processing in epidemiology

lifecycle::is_present for enquosed deprecated NSE arg

Description

lifecycle::is_present is designed for use with args that undergo standard evaluation, rather than non-standard evaluation (NSE). This function is designed to fulfill a similar purpose, but for args we have enquosed in preparation for NSE.

Usage

deprecated_quo_is_present(quo)

Arguments

quo	enquosed arg

Value

bool; was quo "present", or did it look like a missing quosure or have an expr that looked like deprecated() or lifecycle::deprecated()?

Examples

fn <- function(x = deprecated()) {
  deprecated_quo_is_present(rlang::enquo(x))
}

fn() # FALSE
fn(.data$something) # TRUE

# Functions that wrap `fn` should forward the NSE arg to `fn` using
# [`{{ arg }}`][rlang::embrace-operator] (or, if they are working from an
# argument that has already been defused into a quosure, `!!quo`). (This is
# already how NSE arguments that will be enquosed should be forwarded.)

wrapper1 <- function(x = deprecated()) fn({{ x }})
wrapper2 <- function(x = lifecycle::deprecated()) fn({{ x }})
wrapper3 <- function(x) fn({{ x }})
wrapper4 <- function(x) fn(!!rlang::enquo(x))

wrapper1() # FALSE
wrapper2() # FALSE
wrapper3() # FALSE
wrapper4() # FALSE

# More advanced: wrapper that receives an already-enquosed arg:

inner_wrapper <- function(quo) fn(!!quo)
outer_wrapper1 <- function(x = deprecated()) inner_wrapper(rlang::enquo(x))

outer_wrapper1() # FALSE

# Improper argument forwarding from a wrapper function will cause this
# function to produce incorrect results.
bad_wrapper1 <- function(x) fn(x)
bad_wrapper1() # TRUE, bad

cmu-delphi/epiprocess documentation built on Oct. 29, 2024, 5:37 p.m.