We refer to the creation of the binary package as (binary) “build time” and, specifically, we mean when R CMD INSTALL -build is run.
#R library rjava full#
The full details on what it means for a package to be in binary form are given in 4.4. When you attach a package with library(), these cached results are re-loaded and certain objects (mostly functions) are made available for your use.
#R library rjava code#
When the binary package is built (often, by CRAN) all the code in R/ is executed and the results are saved. Things are different with package code, because it is loaded in two steps. When you source() a script, every line of code is executed and the results are immediately made available. We expand on the first point here and the second in the next section. This means your functions need to be thoughtful in the way that they interact The code below R/: package code should only create objects, the vast majorityįunctions in your package will be used in situations that you didn’t imagine. This has big implications for how you write However, we must, in order to appreciate that the code in a package is Statement reflects that it’s hard to even think about this issue with a In a script, code is run … when you run it! The awkwardness of this There are two main differences between code in scripts and packages: Up until now, you’ve probably been writing scripts, R code saved in a file that you execute interactively, perhaps using an IDE and/or source(), or noninteractively via Rscript. There are some departures from the hard-and-fast rules given above, which illustrates that there’s a lot of room for judgment here.
Here are some examples from the actual source of the tidyr package at version 1.1.2.
R file will contain multiple function definitions: such as a main function and its supporting helpers, a family of related functions, or some combination of the two. If a specific function is very large or has lots of documentation, it can make sense to give it its own file, named after the function. This advice should inform your general policy, but there are exceptions to every rule. While you’re free to arrange functions into files as you wish, the two extremes are bad: don’t put all functions into one file and don’t put each function into its own separate file. The file name should be meaningful and convey which functions are defined within. The Tidyverse Style Guide offers some general advice about file names and also advice that specifically applies to files in a package. However, a few more conventions can make the source code of your package easier to navigate and relieve you of re-answering “How should I name this?” each time you create a new file. The only hard rule is that your package should store its function definitions in R scripts, i.e. files with extension.
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