| Type: | Package |
| Title: | Load Configuration Values |
| Version: | 0.0.6 |
| Description: | A simple approach to configuring R projects with different parameter values. Configurations are specified using a reduced subset of base R and parsed accordingly. |
| URL: | https://timtaylor.codeberg.page/ronfig/ |
| BugReports: | https://codeberg.org/TimTaylor/ronfig/issues |
| License: | GPL-2 | GPL-3 |
| Encoding: | UTF-8 |
| RoxygenNote: | 7.3.3 |
| Imports: | carrier, cli, utils |
| Suggests: | knitr, quarto, testthat (≥ 3.0.0) |
| Config/testthat/edition: | 3 |
| VignetteBuilder: | quarto |
| NeedsCompilation: | no |
| Packaged: | 2025-11-21 10:11:09 UTC; tim |
| Author: | Tim Taylor  [aut,
cre, cph] |
| Maintainer: | Tim Taylor <tim.taylor@hiddenelephants.co.uk> |
| Repository: | CRAN |
| Date/Publication: | 2025-11-21 10:30:07 UTC |
Load configuration
Description
Load a user defined configuration from file. By default
(i.e. when as_is = FALSE), load_config() requires inputs to be given as
uniquely-named lists. It first parses the configuration file looking for a
'default' entry. With no additional arguments this will be returned as a list
to the user. If the user specifies an additional list to consider (via the
config argument) then this list is layered on top
(using utils::modifyList()).
list_config() returns the names of (possible) configurations within the
given file. It corresponds to names(load_config(filename, as_is = TRUE)).
Usage
load_config(filename, config, crates, ..., as_is = FALSE, default = "default")
list_config(filename)
Arguments
filename |
Configuration file to read from. |
config |
If If |
crates |
A list of carrier::crate objects which are used to inject functions in to the environment where the configuration file will be evaluated. |
... |
Not currently used. |
as_is |
Should the configuration file be read in as is, without layering on top of
the Defaults to |
default |
The default configuration to use. Not used if |
Details
Configuration files can be specified using a reduced subset of base R. By default this is restricted to the following operators and functions:
-
<-,=,+,-,*,: -
$,[,[[ -
$<-,[<-,[[<- -
c() -
as.Date() -
array(),matrix() -
list(),data.frame() -
Sys.Date(),Sys.time() -
seq(),sequence(), andseq_len() -
file.path() -
modifyList()
We also enable a convenience function, cc, which automatically quotes input
to save typing.
Users can also inject their own functions in to the evaluation environment by supplying a list of crates as an additional argument.
Value
If as_is = FALSE (default), load_config() returns a list contain entries
corresponding to the chosen config.
If as_is = TRUE and no config value specified, a list of all entries in
the evaluated configuration file. If a config value is specified, this
entry is pulled from the list and returned.
list_config() returns a character vector of (possible) configurations
within the given file. It corresponds to
names(load_config(filename, as_is = TRUE)).
Examples
# load the example configuration
file <- system.file("config.R", package = "ronfig")
cat(readChar(file, file.info(file)$size))
# default configuration
str(load_config(file))
# debug configuration
str(load_config(file, "debug"))
# forecast configuration
str(load_config(file, "forecast"))
# Injecting crated function
f <- tempfile()
cat("default <- list(a=mean(1:10))", file = f)
# will fail as mean() not available
tryCatch(with(load_config(f), a), error = conditionMessage)
# will work if we inject crated mean
crate <- carrier::crate(function(x) mean(x))
with(load_config(f, crates = list(mean = crate)), a)
unlink(f)