formatR (version 1.14)

tidy_source: Reformat R code


Read R code from a file or the clipboard and reformat it. This function is based on parse() and deparse(), but it does several other things, such as preserving blank lines and comments, substituting the assignment operator = with <-, and re-indenting code with a specified number of spaces.


  source = "clipboard",
  comment = getOption("formatR.comment", TRUE),
  blank = getOption("formatR.blank", TRUE),
  arrow = getOption("formatR.arrow", FALSE),
  pipe = getOption("formatR.pipe", FALSE),
  brace.newline = getOption("formatR.brace.newline", FALSE),
  indent = getOption("formatR.indent", 4),
  wrap = getOption("formatR.wrap", TRUE),
  width.cutoff = getOption("formatR.width", getOption("width")),
  args.newline = getOption("formatR.args.newline", FALSE),
  output = TRUE,
  text = NULL,


A list with components


the reformatted code as a character vector


the code containing comments, which are masked in assignments or with the weird operator




A character string: file path to the source code (defaults to the clipboard).


Whether to keep comments.


Whether to keep blank lines.


Whether to substitute the assignment operator = with <-.


Whether to substitute the magrittr pipe %>% with R's native pipe operator |>.


Whether to put the left brace { to a new line.


Number of spaces to indent the code.


Whether to wrap comments to the linewidth determined by width.cutoff (roxygen comments will never be wrapped).


An integer in [20, 500]: if a line's character length is at or over this number, the function will try to break it into a new line. In other words, this is the lower bound of the line width. See ‘Details’ if an upper bound is desired instead.


Whether to start the arguments of a function call on a new line instead of after the function name and ( when the arguments cannot fit one line.


Whether to output to the console or a file using cat().


An alternative way to specify the input: if NULL, the function will use the source argument; if a character vector containing the source code, the function will use this and ignore the source argument.


Other arguments passed to cat(), e.g. file (this can be useful for batch-processing R scripts, e.g. tidy_source(source = 'input.R', file = 'output.R')).


Yihui Xie <> with substantial contribution from Yixuan Qiu <>


A value of the argument width.cutoff wrapped in I() (e.g., I(60)) will be treated as the upper bound of the line width. The corresponding argument to deparse() is a lower bound, so the function will perform a binary search for a width value that can make deparse() return code with line width smaller than or equal to the width.cutoff value. If the search fails, a warning will signal, suppressible by global option options(formatR.width.warning = FALSE).

References (an introduction to this package, with examples and further notes)

See Also


Run this code

## a messy R script
messy = system.file("format", "messy.R", package = "formatR")

## use the 'text' argument
src = readLines(messy)

## source code
cat(src, sep = "\n")

## the formatted version
tidy_source(text = src)

## preserve blank lines
tidy_source(text = src, blank = TRUE)

## indent with 2 spaces
tidy_source(text = src, indent = 2)

## discard comments!
tidy_source(text = src, comment = FALSE)

## wanna see the gory truth??
tidy_source(text = src, output = FALSE)$text.mask

## tidy up the source code of image demo
x = file.path(system.file(package = "graphics"), "demo", "image.R")

# to console

# to a file
f = tempfile()
tidy_source(x, blank = TRUE, file = f)

## check the original code here and see the difference

## use global options
options(comment = TRUE, blank = FALSE)

## if you've copied R code into the clipboard
if (interactive()) {
    ## write into clipboard again
    tidy_source("clipboard", file = "clipboard")

## the if-else structure
tidy_source(text = c("{if(TRUE)1 else 2; if(FALSE){1+1", "## comments", "} else 2}"))

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