drake (version 5.2.1)

Makefile_recipe: For make(..., parallelism = "Makefile"), see what your Makefile recipes will look like in advance.

Description

Relevant to "Makefile" parallelism only.

Usage

Makefile_recipe(recipe_command = drake::default_recipe_command(),
  target = "your_target", cache_path = drake::default_cache_path())

Arguments

recipe_command

The Makefile recipe command. See default_recipe_command().

target

character scalar, name of your target

cache_path

path to the drake cache. In practice, this defaults to the hidden .drake/ folder, but this can be customized. In the Makefile, the drake cache is coded with the Unix variable DRAKE_CACHE and then dereferenced with $(DRAKE_CACHE). To simplify things for users who may be unfamiliar with Unix variables, the recipe() function just shows the literal path to the cache.

Value

A character scalar with a Makefile recipe.

Details

Makefile recipes to build targets are customizable. Use the Makefile_recipe() function to show and tweak Makefile recipes in advance, and see default_recipe_command() and r_recipe_wildcard() for more clues. The default recipe is Rscript -e 'R_RECIPE', where R_RECIPE is the wildcard for the recipe in R for making the target. In writing the Makefile, R_RECIPE is replaced with something like drake::mk("name_of_target", "path_to_cache"). So when you call make(..., parallelism = "Makefile", recipe_command = "R -e 'R_RECIPE' -q"), # nolint from within R, the Makefile builds each target with the Makefile recipe, R -e 'drake::mk("this_target", "path_to_cache")' -q. But since R -q -e fails on Windows, so the default recipe_command argument is "Rscript -e 'R_RECIPE'" (equivalently just "Rscript -e"), so the default Makefile recipe for each target is Rscript -e 'drake::mk("this_target", "path_to_cache")'.

See Also

default_recipe_command(), r_recipe_wildcard(), make()

Examples

# NOT RUN {
# Only relevant for "Makefile" parallelism.
# Show an example Makefile recipe.
Makefile_recipe(cache_path = "path") # `cache_path` has a reliable default.
# Customize your Makefile recipe.
Makefile_recipe(
  target = "this_target",
  recipe_command = "R -e 'R_RECIPE' -q",
  cache_path = "custom_cache"
)
default_recipe_command() # "Rscript -e 'R_RECIPE'" # nolint
r_recipe_wildcard() # "R_RECIPE"
# }
# NOT RUN {
test_with_dir("Quarantine side effects.", {
load_mtcars_example() # Get the code with drake_example("mtcars").
# Look at the Makefile generated by the following.
# make(my_plan, paralleliem = "Makefile") # Requires Rtools on Windows. # nolint
# Generates a Makefile with "R -q -e" rather than
# "Rscript -e".
# Be aware the R -q -e fails on Windows.
# make(my_plan, parallelism = "Makefile", jobs = 2, # nolint
#   recipe_command = "R -q -e") # nolint
# Same thing:
clean() # Start from scratch.
# make(my_plan, parallelism = "Makefile", jobs = 2, # nolint
#   recipe_command = "R -q -e 'R_RECIPE'") # nolint
clean() # Start from scratch.
# make(my_plan, parallelism = "Makefile", jobs = 2, # nolint
#   recipe_command = "R -e 'R_RECIPE' -q") # nolint
})
# }