tar_envir: For developers only: get the environment of the current...

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

For developers only: get the environment of the current target.

Description

For developers only: get the environment where a target runs its command. Designed to be called while the target is running. The environment inherits from tar_option_get("envir").

Usage

tar_envir(default = parent.frame())

Arguments

default

Environment, value to return if tar_envir() is called on its own outside a targets pipeline. Having a default lets users run things without tar_make(), which helps peel back layers of code and troubleshoot bugs.

Details

Most users should not use tar_envir() because accidental modifications to parent.env(tar_envir()) could break the pipeline. tar_envir() only exists in order to support third-party interface packages, and even then the returned environment is not modified.

Value

If called from a running target, tar_envir() returns the environment where the target runs its command. If called outside a pipeline, the return value is whatever the user supplies to default (which defaults to parent.frame()).

See Also

Other utilities: tar_active(), tar_backoff(), tar_call(), tar_cancel(), tar_definition(), tar_described_as(), tar_group(), tar_name(), tar_path(), tar_path_script(), tar_path_script_support(), tar_path_store(), tar_path_target(), tar_source(), tar_store()

Examples

tar_envir()
tar_envir(default = new.env(parent = emptyenv()))
if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) { # for CRAN
tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
tar_script(tar_target(x, tar_envir(default = parent.frame())))
tar_make(x)
tar_read(x)
})
}

wlandau/targets documentation built on April 21, 2024, 6:04 p.m.