tar_helper: Write a helper R script.

In targets: Dynamic Function-Oriented 'Make'-Like Declarative Pipelines

Write a helper R script.

Description

Write a helper R script for a targets pipeline. Could be supporting functions or the target script file (default: ⁠_targets.R⁠) itself.

tar_helper() expects an unevaluated expression for the code argument, whereas tar_helper_raw() expects an evaluated expression object.

Usage

tar_helper(path = NULL, code = NULL, tidy_eval = TRUE, envir = parent.frame())

tar_helper_raw(path = NULL, code = NULL)

Arguments

path	Character of length 1, path to write (or overwrite) code. If the parent directory does not exist, tar_helper_raw() creates it. tar_helper() overwrites the file if it already exists.
code	Code to write to path. tar_helper() expects an unevaluated expression for the code argument, whereas tar_helper_raw() expects an evaluated expression object.
tidy_eval	Logical, whether to use tidy evaluation on code. If turned on, you can substitute expressions and symbols using ⁠!!⁠ and ⁠!!!⁠. See examples below.
envir	Environment for tidy evaluation.

Details

tar_helper() is a specialized version of tar_script() with flexible paths and tidy evaluation.

Value

NULL (invisibly)

See Also

Other scripts: tar_edit(), tar_github_actions(), tar_renv(), tar_script()

Examples

# Without tidy evaluation:
path <- tempfile()
tar_helper(path, code = x <- 1)
tar_helper_raw(path, code = quote(x <- 1)) # equivalent
writeLines(readLines(path))
# With tidy evaluation:
y <- 123
tar_helper(path, x <- !!y)
writeLines(readLines(path))

targets documentation built on Oct. 3, 2024, 1:11 a.m.