Learn R Programming

{styler}: Non-Invasive Pretty Printing of R Code

Overview

styler formats your code according to the tidyverse style guide (or your custom style guide) so you can direct your attention to the content of your code. It helps to keep the coding style consistent across projects and facilitate collaboration. You can access styler through

the RStudio Addin as demonstrated below
R functions like style_pkg(), style_file() or style_text()
various other tools described in vignette("third-party-integrations")

Installation

You can install the package from CRAN.

install.packages("styler")

Or get the development version from GitHub:

# install.packages("remotes")
remotes::install_github("r-lib/styler")

Documentation

The following online docs are available:

Acknowledgments

Hex sticker font is Gayathri, and the image is taken from icon made by Freepik and available at flaticon.com.

Copy Link

Version

Install

install.packages('styler')

Monthly Downloads

71,332

Version

1.11.0

License

MIT + file LICENSE

Issues

Pull Requests

Stars

Forks

Repository

https://github.com/r-lib/styler

Homepage

https://styler.r-lib.org

Maintainer

Lorenz Walthert

Last Published

October 13th, 2025

Functions in styler (1.11.0)

alignment_serialize_column

Serialize all lines for a given column

assert_filetype

Make sure all supplied file types are allowed

cache_find_path

Where is the cache?

alignment_serialize_line

Serialize one line for a column

cache_find_block

Find the groups of expressions that should be processed together

Clear the cache

cache_by_expression

alignment_serialize

Serialize text from a parse table

bind_with_child

Bind a parse table with one of its children

Assert text to be of positive length and replace it with the empty string otherwise.

Remember the past to be quicker in the future

Activate or deactivate the styler cache

Show information about the styler cache

catch_style_file_output

Capture and post-process the output of style_file without causing side effects

Write to the cache

Check token validity

construct_vertical

Construct an object of class vertical

cache_more_specs

Create more specs

cache_is_activated

Check if a cache is activated

combine_children

Combine child and internal child

Construct paths of a tree object given the paths of *-in.R files

contains_else_expr_that_needs_braces

Check whether an else expression needs braces

create_style_guide

Create a style guide

delete_if_cache_directory

Delete a cache or temp directory

communicate_warning

Communicate a warning if necessary

compute_indent_indices

Compute the indices that need indention

assert_transformers

Assert the transformers

Make a key for R.cache

context_to_terminals

Propagate context to terminals

enhance_mapping_special

Enhance the mapping of text to the token "SPECIAL"

choose_indention

Choose the indention method for the tokens

dir_without_._one

dir(), but with full names, ignored case, and included hidden files and recursive.

enrich_terminals

Enrich flattened parse table

context_towards_terminals

Update the a parse table given outer context

find_line_break_position_in_multiline_call

Find index of the token before which the line should be broken

copy_to_tempdir

Copy a file to a temporary directory

create_node_from_nested

Create node from nested parse data

find_pos_id_to_keep

Find the pos ids to keep

communicate_summary

Communicate the summary of styling

ensure_correct_txt

Ensure a correct text of all strings and numeric constants

ensure_last_n_empty

Ensure there is one (and only one) blank line at the end of a vector

Convert roxygen comments to Rd code

compute_parse_data_nested

Obtain a nested parse table from a character vector

Create a terminal token

find_blank_lines_to_next_expr

Find blank lines

create_node_from_nested_root

Convert a nested data frame into a node tree

The elements that are added to this environment are:

identify_raw_chunks

Identifies raw Rmd or Rnw code chunks

extract_terminals

Extract terminal tokens

finalize_raw_chunks

Drop start / stop, when formatting is turned off

expressions_are_identical

Check whether two expressions are identical

Find dontrun and friend sequences

convert_newlines_to_linebreaks

Replace the newline character with a line break

dir(), but without dot-prefix and different defaults

Replace single quotes with double quotes

local_test_setup

Establish testing setup for current environment

Create a tree from text

Construct *-out.R from a *-in.R

env_add_stylerignore

Add positional information of token to next terminal

Create valid pos_ids if possible

math_token_spacing

Specify spacing around math tokens

lookup_new_special

Lookup which new tokens were created from "SPECIAL"

identify_start_to_stop_of_roxygen_examples_from_text

Figure out where code examples start and stop

flatten_operators

Flatten some token in the nested parse table based on operators

get_addins_style_transformer_name

Return the style function or name

next_non_comment

Find the index of the next or previous non-comment in a parse table.

Obtain robust parse data

flatten_operators_one

Flatten one level of nesting with its child

n_times_faster_with_cache

Times two function calls with temporarily enabled cache

find_blank_lines_to_next_block

Number of lines between cache blocks

Tell me what the next terminal is

get_knitr_pattern

Get chunk pattern

find_start_pos_id

Find legit starting value for a new positional id

if_for_while_part_requires_braces

Check if if, for or while loop expression require a braces.

default_style_guide_attributes

Initialize default style guide attributes

Flatten a parse table

is_insufficiently_parsed_string

Identify strings that were not fully parsed

initialize_attributes

Initialize attributes

map_filetype_to_pattern

Map the file type to a corresponding regular expression

is_code_chunk_header_or_xaringan_or_code_output

Identify spinning code chunk header or xaringan

get_engine_pattern

What's the engine pattern for rmd code chunks?

Identify comments that are shebangs

Specify what is re-indented how

scope_normalize

Convert the styling scope to its lower-level representation

needs_rd_emulation

Check if rd emulation is required with roxygen2::roc_proc_text()

match_stop_to_start

Match a stop candidate to a start

remove_dont_mask

Remove dont* mask

set_line_break_around_curly_curly

Styling around \{\{

post_parse_roxygen

Changing the line definition

set_line_break_before_curly_opening

Set line break before a curly brace

separate_chunks

Separate chunks within Rmd and Rnw contents

Prettify R code in current working directory

nest_parse_data

Nest a flat parse table

Lookup all tokens that have a unique token-text mapping

is_single_indent_function_declaration

Is the function declaration single indented?

remove_roxygen_header

Remove roxygen header

Repeat elements of a character vector times times and collapse it

Check if text is cached

Save parsing from text

needs_indention

Check whether indention is needed

Prettify a package

parse_transform_serialize_r

Parse, transform and serialize text

needs_indention_one

Check whether indention is needed

hash_standardize

Standardize text for hashing

Set the multi-line column

has_crlf_as_first_line_sep

Check if a string uses CRLF EOLs

find_tokens_to_update

Find the tokens to update when applying a reference indention

set_line_break_if_call_is_multi_line

Set line break for multi-line function calls

Drop-in replacement for xfun:::invalid_utf8()

Print styled code

Helper for setting spaces

parse_transform_serialize_r_block

Parse, transform and serialize a nested parse table

Prettify R source code

style_selection

Styles the highlighted selection in a .R or .Rmd file.

style_space_around_math_token

Style spacing around math tokens

What is a parse table representing?

parse_transform_serialize_roxygen

Parse, transform and serialize roxygen comments

pd_is_multi_line

Check whether a parse table is a multi-line token

Shallowify the parse table

Get the value of an option

set_unindention_child

Unindent a child if necessary

Parse roxygen comments into text

make_transformer

Closure to return a transformer function

set_style_transformers

Asks the user to supply a style

text_to_flat_pd

Creates a flat parse table with minimal initialization

Turn off styling for parts of the code

style_active_pkg

Wrapper around style_pkg() for access via Addin.

stylerignore_consolidate_col

Consolidate columns after a merge

Create the path to a test that file

Prettify arbitrary R code

Style files with R source code

Stylers for RStudio Addins

parser_version_set

Work with parser versions

set_and_assert_arg_filetype

Set the file type argument

style_roxygen_code_example_one

Style a roxygen code example with exactly one @example or @exampleIf

style_space_around_token

Set spacing of token to a certain level

Obtain token table from text

set_space_around_operator

Set spaces around operators

style_text_without_curly_curly

style_text() without rules for \{\{

transform_and_check

Transform a file an check the result

start_comments_with_space

Start comments with a space

Package options

style_roxygen_code_example

Style a roxygen code example that may contain dontrun and friends

update_indention

Update indention information of parse data

transform_mixed_non_empty

Ensure for .Rmd and friends that a code chunk without code is formatted as a code chunk without any lines.

serialize_parse_data_flattened

Serialize flattened parse data

parse_tree_must_be_identical

Check whether a round trip verification can be carried out

styler: Non-Invasive Pretty Printing of R Code

Transform code from R, Rmd or Rnw files

set_line_break_after_opening_if_call_is_multi_line

Sets line break after opening parenthesis

Apply a function to the contents of a file

Standardize paths in root

set_regex_indention

Set indention of tokens that match regex

unindent_function_declaration

Revert the indention of function declaration header

Transform a file and output a customized message

verify_roundtrip

Verify the styling

Drop-in replacement for xfun::write_utf8()

try_transform_as_r_file

Style a file as if it was an .R file

specify_transformers_drop

Specify which tokens must be absent for a transformer to be dropped

Drop-in replacement for xfun::read_utf8(), with an optional warn argument.

save_after_styling_is_active

Heuristic to see if a file styled with the addin should be saved or not.

roxygen_remove_extra_brace

Fix tools::parse_Rd() output

split_roxygen_segments

Split text into roxygen and non-roxygen example segments

set_space_between_eq_sub_and_comma

Set space between EQ_SUB and "','"

set_space_between_levels

Set space between levels of nesting

transform_utf8_one

Potentially transform a file

test_transformers_drop

Test transformers_drop for consistency

style_roxygen_code_example_segment

Style a roxygen code example segment

test_transformer

Transforming test input with a transformer function

test_collection

Run a collection of tests

Test the dry argument

style_roxygen_example_snippet

Given a code snippet is dont* or run, style it

validate_new_pos_ids

Validate sequence of new position ids

transform_files

Transform files with transformer functions

Unindent a child

wrap_expr_in_expr

Wrap an expression into an expression

update_newlines

Update the newlines attribute

wrap_if_else_while_for_function_multi_line_in_curly

Wrap if-else, while and for statements in curly braces

transform_mixed

Transform mixed contents

tidyverse_style

The tidyverse style

wrap_expr_in_curly

Wrap an expression in curly braces

update_indention_ref

Update the indention reference

Transform a flat parse table with a list of transformers

wrap_else_multiline_curly

Add curly braces to else

token_is_on_aligned_line

Check if tokens are aligned

wrap_subexpr_in_curly

Wrap a sub-expression in curly braces

wrap_multiline_curly

Wrap a multi-line statement in curly braces

transformers_drop

Remove transformers that are not needed

add_stylerignore

Adds the stylerignore column

add_spaces_or_newlines

Concentrate newlines or spaces in a string

alignment_has_correct_spacing_around_comma

Check if spacing around comma is correct

alignment_ensure_no_closing_brace

Ensure the closing brace of the call is removed

add_token_terminal

Add information about previous / next token to each terminal

add_cache_block

Add the block id to a parse table

add_id_and_short

Add column pos_id and short

alignment_col1_all_named

Checks if all arguments of column 1 are named

alignment_has_correct_spacing_around_eq_sub

Check if spacing around = is correct

apply_stylerignore

Ensure correct positional information for stylerignore expressions

add_roxygen_mask

Add the roxygen mask to code

apply_transformers

Apply transformers to a parse table

alignment_drop_last_expr

Remove last expression

apply_ref_indention_one

Applying reference indention of a target token

apply_ref_indention

Apply reference indention to tokens

alignment_drop_comments

Remove all comment tokens

alignment_ensure_trailing_comma

Ensure last pd has a trailing comma