The goal of typos is to provide a flexible warning when commonly mis-typed functions are called. Functions with typing errors will still be evaluated and a warning will be output. It also provides the user with a convenient function to define their own typos.
Installation
You can install the development version of typos from GitHub with:
Example
For example, without typos installed, mistyping the functions names() as nameS() will throw an error.
nameS(mtcars) #> Warning: Typo of "names()" detected in "nameS()" #> [1] "mpg" "cyl" "disp" "hp" "drat" "wt" "qsec" "vs" "am" "gear" "carb"
But, with typos, the function is still evaluated, and rather than an Error, a Warning is produced.
Generating typos
The key to typo is the .typo() function. To generate a typo, we use the following syntax:
For example, the above nameS typo is generated with
Wrapping
The way .typo() works is to generate a wrapper function around the correctly spelled function. This wrapper function sends a warning to the user, but still evaluates the “proper” function.
The wrapper function, nameS looks like this:
nameS #> function(...) #> { #> requireNamespace("base",quietly=T) #> .call <- match.call() #> .incorrect_call <- as_name(.call[[1]]) #> .call[[1]] <- quote(names) #> .typo_alert("names",.incorrect_call) #> eval_tidy(.call,env=rlang::caller_env()) #> } #> <environment: namespace:typos>
Notice that all the arguments passed to nameS(...) are forwarded on to names(...)
Other packages
As well as the correctly spelled function, the .typo() function can take a .package argument (this will always be the second unnamed argument, so code can be neater). By default, this will be the base package, but any other package will need to be specified (this includes default packages like stats).
Rnorm <- .typo(rnorm,stats)
Within the wrapper function, this changes two things. The argument passed to requireNamespace() will match this package, as will the “proper” function call
Rnorm #> function(...) #> { #> requireNamespace("stats",quietly=T) #> .call <- match.call() #> .incorrect_call <- as_name(.call[[1]]) #> .call[[1]] <- quote(rnorm) #> .typo_alert("rnorm",.incorrect_call) #> eval_tidy(.call,env=rlang::caller_env()) #> } #> <environment: 0x00000242b5f8fa40>
Warning
Caution should be used if the misspelled version of your function already exists as a function in it’s own right. The .typo() will overwrite the other “correct” function with the new typo function. For this reason, it is recommended that typos be the first package loaded to ensure functions loaded in other packages can overwrite the Exported typos provided here.
Code of Conduct
Please note that the typos project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.