FAQ ⏐ INSTALL ⏐ CUSTOMIZE ⏐ MORE DETAILS
This package provides indentation guide bars in Emacs, with optional tree-sitter enhancement:
- Optimized for speed.
- Optional tree-sitter support, including scope focus, among other features.
- Supports either space or tab-based indentation.
- Bar appearance is highly configurable: color, blending, width, position within the character, vertical fill/blank pattern, even zigzag (see examples).
- Bars can have optional depth-based coloring, with a cyclical color palette you can customize.
- Fast current-depth bar highlighting with configurable bar color and/or appearance changes.
- Bars can appear on blank lines.
- Bar depth can be held constant inside multi-line strings and lists.
- Works in the terminal, using a vertical bar character.
See the release NEWS.
- I don't see anything/bars are garbled!
While most do, not all Emacsen support stipples; see Compatibility. - How can I find out if my Emacs supports stipples?!
See Testing Stipples. - These bars are too intrusive!
Reduce the:blend
value inindent-bars-color
closer to zero. Consider disablingindent-bars-color-by-depth
. - I can barely see the bars!
Increase the:blend
value inindent-bars-color
closer to one. - I want completely unique indent guide-bars so as to flex on my colleagues!
Check the Examples for some ideas. The sky is the limit (submit your examples). - I use Emacs on the terminal, you insensitive clod!
indent-bars
will just work for you (though you don't get any fancy bar patterns). - I use graphical Emacs, but am an extreme minimalist. All my outfits are gray. Including my socks.
Maybe this will suit you? Otherwise, you can turn off the stipple and use old fashioned│
characters withindent-bars-prefer-character
. - The current bar highlight is so fast, but it flashes too rapidly during scrolling!
Update to v0.2.2 or later and setindent-bars-depth-update-delay
to a comfortable number like 0.1s (0.075s is the default). If you like the crazy-fast updates, set this to 0.
- I get too many bars inside function definitions and calls.
You can turn onindent-bars-no-descend-lists
or even use tree-sitter to help. - I want a bar in the very first column!
Setindent-bars-starting-column
to 0. - indent-bars seems to be conflicting with another package I use.
See these workarounds. - In my brace language (C, JS, etc.) I sometimes get fewer bars than I expected!
Your mode syntax likely interprets{
/}
as list context, and you haveindent-bars-no-descend-lists=t
. Either disable this feature, or see this config for another option. - In my paren language (Elisp, Scheme, etc.) the bars disappear on some lines!
You probably need to disableindent-bars-no-descend-lists
there: most lines of these languages are inside "continuing lists", so it makes little sense to inhibit bars there. - Bars are missing on lines with tabs!
You likely haveindent-tabs-mode
set tonil
in a buffer with a tab-indented file. See this for more.
- I turned on treesitter support but nothing happened
You need to configureindent-bars-treesit-scope
(and possiblywrap
) for your language(s) of interest. More info. - My treesitter scope makes no sense!
A common mistake is adding too many node types for your language to theindent-bars-treesit-scope
variable. Start small, with thing you know you want (function, method, class, etc.). - How can I change the style of the out-of-scope bars?
Using an alternate set ofts-
customizations. - What if I want out-of-scope text to have the default style, and in-scope text to be special?
You want to setindent-bars-ts-styling-scope
to'in-scope
.
indent-bars
is on ELPA; simply install with Emacs' package facilities, and configure by calling indent-bars-mode
in your desired mode hooks.
Simple default config using use-package
:
(use-package indent-bars
:hook ((python-mode yaml-mode) . indent-bars-mode)) ; or whichever modes you prefer
Important
treesitter
users: indent-bars
needs your help! If you have come up with good settings for treesitter "wrap" and "scope" for your favorite languages, please add them to the Wiki! If we get a large enough collection they may be included as defaults.
Configures tree-sitter
and ignore-blank-line
support for an example language.
(use-package indent-bars
:config
(require 'indent-bars-ts) ; not needed with straight
:custom
(indent-bars-no-descend-lists t) ; no extra bars in continued func arg lists
(indent-bars-treesit-support t)
(indent-bars-treesit-ignore-blank-lines-types '("module"))
;; Add other languages as needed
(indent-bars-treesit-scope '((python function_definition class_definition for_statement
if_statement with_statement while_statement)))
;; Note: wrap may not be needed if no-descend-list is enough
;;(indent-bars-treesit-wrap '((python argument_list parameters ; for python, as an example
;; list list_comprehension
;; dictionary dictionary_comprehension
;; parenthesized_expression subscript)))
:hook ((python-base-mode yaml-mode) . indent-bars-mode))
See tree-sitter, and also the Wiki page.
Important
For indent-bars
to display fancy guide bars, your port and version of emacs must correctly display the :stipple
face attribute. Most do, but some do not.
Known :stipple
support, by Emacs build:
- Linux:
- "Pure GTK" (
--with-pgtk
build flag) versions support stipples starting with Emacs v30. There was a display bug that caused them to appear incorrectly (as reverse video) and lead to crashes in Emacs 29 and earlier; these issues were fixed in Emacs here and will be released with Emacs 30. - Cairo builds (
--with-cairo
, the default) have been reported not to display stipples (but only in some cases). - All other builds support stipples.
- "Pure GTK" (
- Mac:
- Windows: Emacs on Windows will support stipples starting at v30.
- Android: Android builds (to appear with Emacs 30) support stipples.
- Haiku: Haiku Emacs builds will support stipples starting with v30.
- Terminal: Stipples are not supported on terminal emacs. Character display is automatically selected.
Please open an issue with any updates/corrections to this list. See also Testing Stipples.
indent-bars
can also be used without stipples, drawing a simple vertical character (like │
) instead. It automatically does this in non-graphical displays (terminals), but this can be made the default; see Character Display.
Note
indent-bars
is highly flexible and can be adapted to most situations. It can't anticipate all nuances of different languages, modes, and user preferences, however, so "some assembly may be required". If you arrive at customizations you are happy with for a given mode, please consider adding to the Wiki page.
M-x customize-group indent-bars
is the easiest way to customize everything about the appearance and function of indent-bars
(check sub-groups too). There are many customization variables and bar styling in particular is highly configurable, so use Customize!
Tip
The easiest way to achieve a particular style is to customize the groups indent-bars
, sub-group indent-bars-style
and (if you use TS) indent-bars-ts
+ indent-bars-ts-style
. While in the Customize interface, pull up one of your buffers with bars in another window on the same frame. When you make changes to variables (C-c C-c
is convenient in custom buffers), the bar style/etc. will automatically update. When you are happy, you can either "Set for Future Sessions", or "Show Saved Lisp Expression" for the variables you changed and copy them into your init file.
See some examples with relevant settings.
The main customization variables are categorized below. See the documentation of each variable for more details on the valid values.
Custom variables for configuring bar color, including depth-based palettes:
indent-bars-color
: The main bar color, either a color name or face, from which foreground or background color will be taken. Also used to set a:blend
factor, to blend colors into the frame's background color.indent-bars-color-by-depth
: How and whether to alter the color of the indent bars by their indentation depth. Defaults to using the foreground of theoutline-*
faces, but many options are possible, including face sets or a custom color palette.
Variables affecting the visual appearance of bars (color aside):
indent-bars-width-frac
: The fractional width of the bar ([0-1], a fraction of a single character's width).indent-bars-pad-frac
: The fractional padding offset of the bar from the left edge of the character.indent-bars-pattern
: A string specifying the vertical structure of the bar (space=blank, non-space=filled). Scaled to the height of one character.indent-bars-zigzag
: A fractional left-right zigzag to apply to consecutive groups of identical non-space characters inpattern
.
Configuration for highlighting the current indentation bar depth:
indent-bars-highlight-current-depth
: How and whether to highlight the bars at the indentation depth of the current line. The current depth bar can change color (including blending with the pre-existing color), as well as appearance (size, pad, pattern, zigzag).indent-bars-highlight-selection-method
: Method used to select which bar is highlighted as the current depth. The default ('context
) considers surrounding lines for a more natural selection depth.indent-bars-depth-update-delay
: Command delay in seconds after which depth highlighting occurs.
Configuration variables for bar position and line locations (including on blank lines):
indent-bars-starting-column
: column to use for the first bar (default: one indent spacing). Can be set in special modes which start at an unusual fixed offset, or set to 0 to get "column 0" bars (which are possibly superfluous given the left buffer edge).indent-bars-spacing-override
: Normally the number of spaces for indentation is automatically discovered from the mode and other variables. If that doesn't work for any reason, it can be explicitly overridden using this variable.indent-bars-display-on-blank-lines
: Whether to display bars on blank lines contiguous with lines already showing bars. By default the maximum number of adjacent bars on non-blank lines is used for a blank lines, but setting this toleast
instead uses the least number of adjacent line bars.indent-bars-no-descend-string
: Whether to inhibit increasing bar depth inside of strings.indent-bars-no-descend-list
: Whether to inhibit increasing bar depth inside of lists. Note that this can optionally be configured with a list of list-opening chars (e.g.'(?\( ?\[)
?) to select only certain list context (useful for c-based modes, where{}
braces are a list syntax).
Custom variables affecting character-based bar display, e.g. in the terminal:
indent-bars-prefer-character
: Use characters to display the vertical bar instead of stipples. This occurs automatically on non-graphical displays (terminals), but this variable can be used to always prefer character-based display. Useful if your version of GUI Emacs does not support:stipple
patterns.indent-bars-no-stipple-char
: The character to use when stipples are unavailable or disabled. Defaults to the vertical box character│
. Other good options include┃
,┋
, and║
.indent-bars-no-stipple-char-font-weight
: Optional font weight to use for the face displaying the no-stipple character.indent-bars-unspecified-bg|fg-color
: Colors to use for the frame background and default foreground when they are unspecified (e.g. in terminals). If you intend to useindent-bars
in the terminal, set to the terminal background/foreground colors you use.
For more information, check the details.
indent-bars-treesit-support
: Whether to use tree-sitter (if available) to (optionally) highlight the current scope and help determine bar depth.indent-bars-treesit-scope
: A mapping of language to tree-sitter scope node types (as symbols), for local scope highlight (aka scope focus).indent-bars-treesit-scope-min-lines
: The minimum number of lines a scope node must occupy to be considered a valid containing scope.indent-bars-treesit-update-delay
: Delay in seconds for updating the treesitter scope highlight.indent-bars-treesit-wrap
: A mapping of language to tree-sitter wrap types (as symbols), to avoid adding extra bars e.g. in wrapped function arguments. Note that this is considered only after theno-descend
options above (which may be sufficient on their own).indent-bars-treesit-ignore-blank-lines-types
: A list of tree-sitter node types (as strings) inside of which to inhibit styling blank lines, like "module".indent-bars-ts-styling-scope
: Determine whether the*-ts-*
variables apply to in-scope or (by default) out-of-scope styling. This is important because one of these styles is shared with the bar style in non-TS buffers. This allows the default style in non-TS buffers to match either the in-scope (default) or out-of-scope styling.
By default, if tree-sitter and scope focus are active (indent-bars-treesit-scope
), the style and highlight settings above apply only to the in-scope bars2. You can separately configure an alternate style for the appearance of the out-of-scope bars — i.e. the bars outside the current tree-sitter scope2. Usually you'd want to de-emphasize out-of-scope bars somehow, but that's not required (go crazy).
To customize the alternate bar appearance, you use the parallel set of custom variables with an indent-bars-ts-
prefix. Each of these variables can be set similarly to their default counterparts to fully configure alternate bar appearance, including color, depth highlighting, bar pattern, etc.
You can interchange the role of in-scope and out-of-scope using indent-bars-ts-styling-scope
. This is useful if you prefer to have the default style (e.g. the bar style in non-tree-sitter-enabled buffers) match the out-of-scope style within tree-sitter buffers (i.e. if you want to emphasize scope, not de-emphasize out-of-scope).
Note
Scope focus highlighting is completely independent of current depth highlighting, and you can style them separately, and can enable one or the other, both, or neither.
The ts
custom variables for configuring the alternate styling are:
- [I]
indent-bars-ts-color
indent-bars-ts-width-frac
indent-bars-ts-pad-frac
indent-bars-ts-pattern
indent-bars-ts-zigzag
indent-bars-ts-no-stipple-char-font-weight
- [I]
indent-bars-ts-color-by-depth
- [I]
indent-bars-ts-highlight-current-depth
Each of these parallel variables has the same form as their equivalent non-ts
version (the "parent" variable), with two additions:
- Some (marked with [I] above) can optionally use inheritance from their parent. Inheritance means any missing
:key
based elements are inherited from the in-scope (parent) style. To configure whether this inheritance occurs, you can optionally set these variable values to a cons cell of the form([no-]inherit . value)
, wherevalue
has the normal format for the parent variable.inherit
(the default, if the cons cell is omitted andvalue
is simply used as-is) means that any unspecified:key
values are inherited from the parent variable. The symbolno-inherit
means to omit (rather than inherit) any missing key values for the alternate styling. See below for an example. - For any non-
:key
type values, the specific symbol value'unspecified
can be set to indicate to use the parent's value for that slot.
For example, a setting of:
(setopt indent-bars-ts-color '(inherit unspecified :blend 0.15))
means to configure the color of alternate style bars as follows:
- use the color from the parent variable
indent-bars-color
(since it isunspecified
here) - set
:blend
to 0.15 - inherit any other missing keyword values from
indent-bars-color
The easiest way to configure inheritance and unspecified values in the ts
variables is via the customize interface; see the customize group indent-bars-ts-style
.
Sometimes different indent-bars
settings are appropriate for different major modes. In that case, you can use setq-local
to set the appropriate cutomize variables locally, directly in the mode's hook, prior to enabling indent-bars
:
(add-hook 'emacs-lisp-mode-hook
(lambda ()
(setq-local
indent-tabs-mode t ; make sure tabs-based indenting is on, even if we disable it globally
indent-bars-no-descend-lists nil) ; elisp is mostly continued lists! allow bars to descend inside
(indent-bars-mode 1)))
Note that tree-sitter scope and wrap config are keyed to the parser language, which may be sufficient for tailoring these.
indent-bars
works with either space- or tab-based indentation (see indent-tabs-mode
). If possible, prefer space indentation, as it is faster.
Note that some modes explicitly enable or disable indent-tabs-mode
. If the value of that variable does not match the actual indentation used in a file (e.g. file is indented with tabs, but you have set indent-tabs-mode=nil
), bars may go missing. You should ideally pick one indentation-style (tabs or spaces) per mode and stick to it for all files in that mode, but see dtrt-indent for a package that can adapt this variable by examining the file's contents.
indent-bars
can highlight the bar at the current depth, and supports a few different ways to determine which bar gets selected for highlight (see indent-bars-highlight-selection-method
):
nil
: The simplest version selects the depth of the last-visible bar on the current line for highlight.on-bar
: The old default, which selects the depth of the last visible bar or the "unseen" bar that the first non-blank character on the current line "covers up".context
: The new default, a blend of these two methods. It selects the last-visible bar unless an adjacent non-blank line (above or below) is indented deeper by at least one indent spacing, in which case theon-bar
approach is used.
Experiment with these to see what you prefer.
indent-bars
can optionally use tree-sitter in supported files to enable several features:
- Scope Focus: The current tree-sitter scope can be focused, with out-of-scope bars de-emphasized or in-scope bars emphasized (or actually, styled however you want). This can be configured by specifying matching "scope" node types (e.g. functions, blocks, etc.) for each language of interest. The innermost node (covering sufficient lines) will then be rendered distinctly from out-of-scope bars.
- Selective Blank Line Display: By default,
indent-bars
displays bars on blank lines (though this can be configured), so that they remain continuous. It can be nice to omit the display of blank lines bars at the top structural level (e.g. in a module), to make divisions between top-level constructs more visible. Tree-sitter can helpindent-bars
identify those lines. - Wrap Detection: It can be useful to prevent excess bars inside wrapped entities which move indent to "line things up." These include things like argument lists, literal dictionaries, or other heirarchical multi-line structures. Tree-sitter can help detect these and inhibit unwanted bars (but see also
indent-bars-no-descend-string/list
, which do not require tree-sitter).
Note
indent-bars
' tree-sitter capabilities require Emacs 29 or later built with tree-sitter support, and the appropriate tree-sitter grammars installed for your languages of interest. Additional node type configuration by language is required; see below.
Simply configure indent-bars-treesit-scope
with the languages and node types for which "local scope" highlighting nodes are of interest. This must be done for each tree-sitter language you use. This scope could be as granular as classes and functions, or include detailed block statements. You can disable scoping for "short blocks" using indent-bars-treesit-scope-min-lines
, so that, e.g., a quick if
statement does not capture scope. I recommend starting with the minimal possible set of scope node types, adding as needed.
Tip
If you don't know the name treesitter uses for your language, try M-: (treesit-language-at (point-min))
in a ts-enabled buffer.
indent-bars-treesit-wrap
can be configured in a similar manner (mapping language to wrapping node types). Note that indent-bars-no-descend-list
, which does not require tree-sitter and is on by default, may be sufficient for your uses.
You can assign a single (usually top-level) node type to ignore when drawing bars on blanks linkes; see indent-bars-treesit-ignore-blank-lines-types
(which, please note, is configured as a list of strings, unlike indent-bars-treesit-wrap/scope
).
The easiest way to discover node types of interest (in a buffer with working treesit support) is to M-x treesit-explore-mode
. Then simply highlight the beginning of a line of interest, and look in the treesitter explorer
buffer which pops up for the names of obvious nodes in the tree. Add these types to indent-bars-treesit-scope/wrap
for the language of interest, then M-x indent-bars-reset
and see how you did (this will happen automatically if you make the change in the Customize interface).
Please document good tree-sitter settings for other languages in the Wiki.
indent-bars
in general has good compatibility with other packages. But sometimes conflicts do occur.
indent-bars
by default uses :stipple
face attributes, which have only rarely been used in Emacs in recent decades. Consequently, some packages which inherit the face of underlying text while adding styled overlays, popups, etc. to the buffer neglect to guard against the presence of :stipple
(e.g. this, or this). This becomes more likely if you set indent-bars-starting-column=0
(since often overlays are placed at the line beginning).
If you encounter unwanted bar patterns on text added to your buffer by other packages as seen in these issues, contact the package's maintainer to let them know they should also clear the :stipple
face attribute. You can also try restoring ``indent-bars-starting-column` to the default, if you've changed it.
Sometimes unwanted stipples can be worked around yourself by explicitly setting :stipple
to nil
in appropriate faces, like:
(set-face-attribute face nil :stipple nil)
for some relevant face
(e.g. one from which the package's faces used for overlay/popup inherit). This should be done both when loading indent-bars-mode
and in the after-enable-theme-hook
.
indent-bars
overrides and wraps the font-lock-fontify-region-function
(and, when using treesitter, font-lock-fontify-buffer-function
). Other packages which advise or wrap the functions pointed to by these variables may lead to odd behavior on disabling/re-enabling indent-bars
and/or their associated modes. There is no generic solution to this issue, but the strong recommendation is to enable indent-bars
last, after any other package which overrides font-lock
in this way have been loaded.
If indent-bars-display-on-blank-lines
is set, the newline at the end of blank lines may have a 'display
property set to show the bars. Emacs does not deal correctly with display properties containing newlines when moving by columns. This is not normally a problem, but in one instance it is a nuisance: evil-mode
tries to "preserve" column during line moves, so can trigger this emacs misfeature. The symptom is that point jumps a line and moves over as you move down with evil. A workaround is here.
Stipples are repeating bitmap patterns anchored to the full emacs frame. indent-bars
basically "opens windows" on this fixed pattern to "reveal" the bars.
The fast stipple method used for drawing bars enables lots of interesting patterns.
If you are experiencing issues with stipple bar display (missing, garbled, etc.), and would like to determine if stipples are working correctly in your build of emacs, you can test it as follows.
- In the
*scratch*
buffer, use firstM-x font-lock-mode
to disable fontification - Hit
C-x C-e
just after the last)
in the following code:(let* ((w (window-font-width)) (stipple `(,w 1 ,(apply #'unibyte-string (append (make-list (1- (/ (+ w 7) 8)) ?\0) '(1)))))) (insert "\n" (propertize (concat (make-string 15 ?\s) "THIS IS A TEST" (make-string 15 ?\s)) 'face `(:background "red" :foreground "blue" :stipple ,stipple))))
This should then look something like (note the blue vertical bars):
If you determine that stipples do not work in your version of Emacs, consider upgrading to a version which supports them, reporting the bug, or setting indent-bars-prefer-character=t
.
To get the stipple bars to appear in the correct location within their column, indent-bars
must consider the starting horizontal pixel position of the current window, and "rotate" the stipple pattern accordingly. It does this automatically, per buffer, so you shouldn't ever notice problems, even when re-sizing or re-arranging windows, changing font size, etc. Until v0.5, showing the same buffer side by side in Emacs versions which support pixel-level window width/offsets could lead to unexpected bar artifacts, since the offset applies per-buffer, not per-window. In v0.5, an alternate method for applying per-window stipple patterns was used to solve this.
For terminals, (and everywhere, if indent-bars-prefer-character
is set), indent-bars
will not attempt stipple display, but instead use simple characters (e.g. │
; see an example).
Note that in mixed gui/terminal sessions of the same Emacs process, you may need to M-x indent-bars-reset
when switching a given buffer between graphical and terminal frames.
- Highly customized appearance and position within the character is possible — examples.
- Fastest option: does not need to apply display properties for normal lines with space-based indentation.
- Results in continuous lines even when
line-spacing
is non-nil (vs. gaps with box characters and additional line spacing).
- Works equally for terminal and GUI.
- Works even for emacs ports which do not support or mis-handle stipple display (see Compatibility).
indent-bars
was in part motivated by the inefficiency of older indentation highlight modes, and is designed for speed. It uses stipples (fixed bitmap patterns) and font-lock for fast and efficient bar drawing — simply faces on spaces. Highlighting the current indentation level is essentially free, since it works by filtered remapping of the relevant face.
The heaviest operations are tree-sitter support (especially scope highlighting), and blank-line highlighting. If you experience any speed issues, these are the first settings to experiment with. Using with tab-based indentation may also be slightly (but likely imperceptibly) slower than with space-based.
Both indentation-depth highlighting and current-tree-sitter-scope highlighting are protected by timers to avoid unnecessary loads (e.g. when pixel-scrolling). Note that indentation-depth highlighting is very fast and can safely be set to 0 seconds (though bars will then flash rapidly as you scroll). Tree-sitter scope requires querying the tree-sitter core, which can be somewhat slower, so be careful setting its timer too low.
- indent-guide: An older package that uses overlays with
|
characters. Some reports of performance concerns. Incompatible with company and other related in-buffer modes. - highlight-indentation-mode: Uses overlays to draw indentation guides, and includes a current indentation mode. Partial support for blank line guides.
- highlight-indent-guides: a highly configurable mode for indentation highlight, with color and style options, as well as current depth highlighting.
- hl-indent-scope: Highlights indentation based on language scope - requiring support for each language, uses overlays to draw indentation guides.
- visual-indentation-mode: Full character-based alternating color indentation guides. Package is now archived.
None of the existing packages:
- were fast enough with large files (including current depth highlighting)
- had enough guide appearance configurability
- were able to support depth-based coloring
- offered robust support for guides on blank lines
- had tree-sitter capabilities
I'm grateful for in-depth advice and input on the design of indent-bars
from Eli Zaretski, Stefan Monnier, Dmitry Gutov and many other who opened issues and PRs.
highlight-indentation-mode was a source of good ideas, and indent-bars
adapts the indentation guessing function from this mode. The original idea of using stipples for "better" indent-bars came from this comment by @vlcek.