styler (version 1.1.0)

style_file: Style .R, .Rmd or .Rnw files

Description

Performs various substitutions in the files specified. Carefully examine the results after running this function!

Usage

style_file(path, ..., style = tidyverse_style,
  transformers = style(...), include_roxygen_examples = TRUE)

Arguments

path

A character vector with paths to files to style.

...

Arguments passed on to the style function.

style

A function that creates a style guide to use, by default tidyverse_style() (without the parentheses). Not used further except to construct the argument transformers. See style_guides() for details.

transformers

A set of transformer functions. This argument is most conveniently constructed via the style argument and .... See 'Examples'.

include_roxygen_examples

Whether or not to style code in roxygen examples.

Value

Invisibly returns a data frame that indicates for each file considered for styling whether or not it was actually changed.

Encoding

UTF-8 encoding is assumed. Please convert your code to UTF-8 if necessary before applying styler.

Warning

This function overwrites files (if styling results in a change of the code to be formatted). It is strongly suggested to only style files that are under version control or to create a backup copy.

We suggest to first style with scope < "tokens" and inspect and commit changes, because these changes are guaranteed to leave the abstract syntax tree (AST) unchanged. See section 'Roundtrip Validation' for details.

Then, we suggest to style with scope = "tokens" (if desired) and carefully inspect the changes to make sure the AST is not changed in an unexpected way that invalidates code.

Roundtrip Validation

The following section describes when and how styling is guaranteed to yield correct code.

If the style guide has scope < "tokens", no tokens are changed and the abstract syntax tree (AST) should not change. Hence, it is possible to validate the styling by comparing whether the parsed expression before and after styling have the same AST. This comparison omits comments. styler compares error if the AST has changed through styling.

Note that with scope = "tokens" such a comparison is not conducted because the AST might well change and such a change is intended. There is no way styler can validate styling, that is why we inform the user to carefully inspect the changes.

See section 'Warning' for a good strategy to apply styling safely.

See Also

Other stylers: style_dir, style_pkg, style_text, styler_addins

Examples

# NOT RUN {
# the following is identical but the former is more convenient:
file <- tempfile("styler", fileext = ".R")
xfun::write_utf8("1++1", file)
style_file(file, style = tidyverse_style, strict = TRUE)
style_file(file, transformers = tidyverse_style(strict = TRUE))
xfun::read_utf8(file)
unlink(file)
# }