Bufler.el

Bufler is like a butler for your buffers, presenting them to you in an organized way based on your instructions. The instructions are written as grouping rules in a simple language, allowing you to customize the way buffers are grouped. The default rules are designed to be generally useful, so you don’t have to write your own.

It also provides a workspace mode which allows frames to focus on buffers in certain groups. Since the groups are created automatically, the workspaces are created dynamically, rather than requiring you to put buffers in workspaces manually.

Screenshots

This screenshot shows bufler-list in the top window, and bufler-switch-buffer reading a buffer with completion in the bottom window. Note how the same, recursively grouped buffers are shown in both ways.

This screenshot compares Bufler and Ibuffer showing the same buffers with the default settings. Note how Bufler provides collapsible sections to group and hide uninteresting buffers. It also allows commands to be applied to selected sections: for example, pressing k in this Bufler list would kill the buffers in the groups compilation-mode and completion-list-mode (and, of course, since it calls kill-buffer, any unsaved, file-backed buffers would ask to be saved first).

This screenshot shows Bufler Tabs Mode, which works with the new tab-bar-mode and tab-line-mode from Emacs 27. The tab-bar selects the workspace, and the tab-line selects a buffer in the current workspace.

Installation
Usage
Compared to Ibuffer
Changelog
Credits

Installation

If you’ve installed from MELPA, you’re done!

Quelpa

If you prefer, you may install with quelpa-use-package, like this:

(use-package bufler
  :quelpa (bufler :fetcher github :repo "alphapapa/bufler.el"
                  :files (:defaults (:exclude "helm-bufler.el"))))

To install the additional helm-bufler package, use:

(use-package helm-bufler
  :quelpa (helm-bufler :fetcher github :repo "alphapapa/bufler.el"
                       :files ("helm-bufler.el")))

Usage

Bufler provides four primary, user-facing features. They complement each other, but each one may be used independently.

The command bufler shows a list of buffers grouped according to the defined grouping rules. It allows manipulation of buffers and groups of buffers.
The command bufler-switch-buffer prompts for a buffer with completion and switches to the selected one. Buffers are presented by their “path” in the groups.
The global minor mode bufler-mode allows each frame to have a “workspace,” which is a buffer group selected by the user. When the mode is active, the command bufler-switch-buffer presents only buffers from the current workspace (unless called with a prefix, in which case it shows all buffers), and the current workspace is displayed in the mode line and the frame’s title. Buffers can also be manually assigned to named workspaces.
The global minor mode bufler-tabs-mode uses the new Emacs 27 tab-bar and tab-line features to display workspaces and buffers. The tab-bar shows top-level workspaces (and whatever the selected one is, even if not top-level), and the tab-line shows buffers from the current workspace.

Workflow
Commands
Bindings
Tips
Defining groups
Helm support
Ivy support
Prism support

Workflow

A workflow using Bufler could be something like this:

Start Emacs.
Activate bufler-mode.
Open some buffers, find some files, etc.
When you need to switch buffers, use M-x bufler-switch-buffer. The buffers are presented by group with their “outline paths,” which makes it easier to find the buffer you’re looking for, since they’re organized by project, directory, mode, etc.
If you want to focus on a certain group’s buffers: a. Use C-u C-u M-x bufler-switch-buffer RET and select a buffer; or b. Use M-x bufler-workspace-frame-set RET and select a workspace; or c. Use M-x bufler RET and press f to focus the current frame on a workspace, or F to open a new frame focused on a workspace.
The next time you call bufler-switch-buffer in that frame, it will only offer buffers from that frame’s buffer group, making it easier to find buffers related to the current project. (Of course, existing commands like switch-to-buffer are not affected; Bufler doesn’t interfere with other modes or commands.)
When you need to switch to a buffer in a different group without changing the frame’s workspace, use C-u M-x bufler-switch-buffer to select from all buffers in all groups.
When you need to kill or save a bunch of buffers at once, use bufler-list, put the cursor on a group you want to kill or save, and press k or s. If you want to see which buffers have unsaved (indicated with *) or uncommitted (indicated with edited) changes, you can browse through the list of buffers (enable bufler-vc-state to show VC state for each buffer; this is disabled by default because getting up-to-date information on a buffer’s VC state can be slow).

Then, you can write your own buffer-grouping rules to make them as simple or as complex as you like. They’re just Lisp functions, so you can do anything with them, but the DSL provided by the macro makes simple ones easy to write.

Commands

bufler: Show the Bufler buffer list.
bufler-mode: Enable the Bufler workspace mode, which allows each frame to have a chosen workspace from Bufler’s groups.
bufler-tabs-mode: Enable the Bufler workspace tabs mode, which uses tab-bar-mode and tab-line-mode from Emacs 27+ to display Bufler workspaces and buffers.
bufler-switch-buffer: Switch to a buffer selected from the frame’s workspace. Without any input, switch to the previous buffer. With prefix, select from all buffers. With two prefixes, also set the frame’s workspace.
bufler-workspace-focus-buffer: Set current frame’s workspace to the current buffer’s workspace.
bufler-workspace-frame-set: Set the frame’s workspace. Setting the workspace may be done automatically by bufler-switch-buffer, but this command may be used to set the workspace to a group containing other groups, after which bufler-switch-buffer will present buffers from the selected group and its subgroups.
bufler-workspace-buffer-set: Set the current buffer’s workspace name. With prefix, unset it. Note that, in order for a buffer to appear in a named workspace, the buffer must be matched by an auto-workspace group before any other group.

Bindings

In the Bufler buffer list, these keys are available (use C-h m to get the most up-to-date listing). They operate on all buffers in the section at point.

? Show key bindings Hydra.
1 – 4 Cycle section levels at point.
M-1 – M-4 Cycle top-level sections.
RET Switch to buffer.
SPC Peek at buffer, keeping focus in buffer list.
g Refresh Bufler list (with prefix, force updating buffers’ VC state and grouping).
f Set the current frame’s workspace to the group at point (with prefix, unset).
F Make a new frame whose workspace is the group at point.
N Add buffers to named workspace (with prefix, remove from it).
k Kill buffers.
s Save buffers.

Tips

bufler-switch-buffer works best when completion-styles includes the substring style. It also works well with helm-mode and ivy-mode.
Customize settings in the bufler group.

See the =bufler= info page to view this information in Emacs.

The Bufler groups definition is a list stored in variable bufler-groups. Each element of the list is a function which takes a buffer as its only argument and returns a string naming the group the buffer should be in at that level (or nil if the buffer should not be grouped by the function), or a list of such functions; each list may contain more such lists. Each buffer is matched against these functions in-order until the list of functions is exhausted. A list of functions defines a subgroup which short-circuits other groups at the same level, preventing further grouping outside of the subgroup’s functions. Ultimately, it’s functions all the way down.

If this explanation doesn’t seem clear, please see the examples. Once you get the hang of it, it’s powerful and flexible.

For convenience, the macro bufler-defgroups provides a concise vocabulary for defining groups. Note that the macro does not set the variable bufler-groups, it only expands a groups form, so you should use, e.g. (setf bufler-groups (bufler-defgroups ...)) to actually set the groups.

Default groups example

The default groups are defined like this:

(bufler-defgroups
  (group
   ;; Subgroup collecting all named workspaces.
   (auto-workspace))
  (group
   ;; Subgroup collecting all `help-mode' and `info-mode' buffers.
   (group-or "*Help/Info*"
             (mode-match "*Help*" (rx bos "help-"))
             (mode-match "*Info*" (rx bos "info-"))))
  (group
   ;; Subgroup collecting all special buffers (i.e. ones that are not
   ;; file-backed), except `magit-status-mode' buffers (which are allowed to fall
   ;; through to other groups, so they end up grouped with their project buffers).
   (group-and "*Special*"
              (lambda (buffer)
                (unless (or (funcall (mode-match "Magit" (rx bos "magit-status"))
                                     buffer)
                            (funcall (mode-match "Dired" (rx bos "dired"))
                                     buffer)
                            (funcall (auto-file) buffer))
                  "*Special*")))
   (group
    ;; Subgroup collecting these "special special" buffers
    ;; separately for convenience.
    (name-match "**Special**"
                (rx bos "*" (or "Messages" "Warnings" "scratch" "Backtrace") "*")))
   (group
    ;; Subgroup collecting all other Magit buffers, grouped by directory.
    (mode-match "*Magit* (non-status)" (rx bos (or "magit" "forge") "-"))
    (auto-directory))
   ;; Subgroup for Helm buffers.
   (mode-match "*Helm*" (rx bos "helm-"))
   ;; Remaining special buffers are grouped automatically by mode.
   (auto-mode))
  ;; All buffers under "~/.emacs.d" (or wherever it is).
  (dir user-emacs-directory)
  (group
   ;; Subgroup collecting buffers in `org-directory' (or "~/org" if
   ;; `org-directory' is not yet defined).
   (dir (if (bound-and-true-p org-directory)
            org-directory
          "~/org"))
   (group
    ;; Subgroup collecting indirect Org buffers, grouping them by file.
    ;; This is very useful when used with `org-tree-to-indirect-buffer'.
    (auto-indirect)
    (auto-file))
   ;; Group remaining buffers by whether they're file backed, then by mode.
   (group-not "*special*" (auto-file))
   (auto-mode))
  (group
   ;; Subgroup collecting buffers in a projectile project.
   (auto-projectile))
  (group
   ;; Subgroup collecting buffers in a version-control project,
   ;; grouping them by directory.
   (auto-project))
  ;; Group remaining buffers by directory, then major mode.
  (auto-directory)
  (auto-mode))

Group types

The following group types are available in bufler-defgroups. Note that each one is expanded into a lambda, so they may also be called by funcall (see example above).

Meta types

These types compose multiple of the other types into a single group.

group (TYPE...) Define a subgroup matching given types, which short-circuits other groups at the same level.
group-not (NAME TYPE) Groups buffers which do not match the given type.
group-and (NAME TYPE...) Groups buffers which match all of the given types.
group-or (NAME TYPE...) Groups buffers which match any of the given types.

Auto types

These types automatically create groups for the buffer’s attribute of this type.

auto-directory Buffer’s directory.
auto-file Buffer’s file name.
auto-indirect Whether the buffer is indirect (e.g. a cloned indirect buffer).
auto-mode Buffer’s major mode.
auto-project Buffer’s version-control project directory according to project.el.
- auto-parent-project Like auto-project, but if the buffer’s parent directory is in a different project, use that one instead. Useful for git worktrees, where auto-project would show each worktree as a separate project.
auto-projectile Buffer’s project as defined in the projectile package (if installed).
auto-special Whether the buffer is special (i.e. whether its name starts with *).
auto-tramp Whether the buffer is opened via Tramp.
auto-workspace The buffer’s named workspace, if any.

Regexp types

These types match a value against a buffer’s attribute and group buffers which match.

filename-match (NAME REGEXP) Match a regular expression against the buffer’s filename, if it has one.
name-match (NAME REGEXP) Match a regular expression against the buffer’s name.
mode-match (NAME REGEXP) Match a regular expression against the buffer’s major-mode.

Other types

dir (DIRS DEPTH) Groups buffers which match one of the given DIRS. DIRS may be one or a list of directory paths. DEPTH may be nil or a depth above which to produce subdirectory groups (a feature probably broken at the moment). See example above.
hidden Groups buffers which are hidden (i.e. whose names start with a space and do not visit a file).

Helm support

Bufler does not require nor depend on Helm, but because it uses completing-read, it requires no special configuration to work with helm-mode for selecting buffers.

To show Bufler’s grouped buffers in a Helm-specific command, a separate helm-bufler package is available, which includes helm-bufler-source, a Helm source that shows buffers in the current workspace (or when the Helm command is called with C-u, all buffers). It looks like this when showing all buffers:

After installing the package (see installation instructions above), use it like this:

(helm :sources '(helm-bufler-source))

Ivy support

Bufler does not require nor depend on Ivy, but because it uses completing-read, Bufler requires no special configuration to work with ivy-mode for selecting buffers. For example, this shows bufler-switch-buffer with ivy-mode activated (in the spacemacs-dark theme):

Prism support

Bufler does not require nor depend on Prism, but you can use Prism’s level faces with Bufler by using M-x customize-option RET bufler-face-prefix RET and choosing the Prism faces option. For example (showing an earlier version of the package, when it was called Sbuffer):

Compared to Ibuffer

Bufler is primarily about grouping buffers automatically and dynamically, using smart, customizeable rules. While Ibuffer provides some powerful grouping features, they are restricted to single-level grouping, and they require extensive, manual configuration. Bufler offers recursive, multi-level grouping, and a set of default groups is provided which are designed to be generally useful. Bufler presents groups in bufler-list using the magit-section library, which allows groups and buffers to be toggled, marked, and operated on with commands.

Ibuffer groups must be manually and individually specified. So, for example, to group project A’s buffers into one group, and project B’s into another, Ibuffer requires the user to make a group for each project. Bufler provides a set of automatic grouping rules that create groups automatically. For example, with the rule (auto-project), Bufler would create one group for project A’s buffers and another for project B’s. When those projects’ buffers are closed, the groups are automatically removed.

Bufler also provides optional workspace features in the form of bufler-mode, which helps focus a frame on a group of buffers. When it’s active, the command bufler-switch-buffer presents buffers from that frame’s selected workspace; when called with a prefix argument, it presents all buffers, and then switches the frame’s workspace to the selected buffer’s group.

Of course, Ibuffer is a mature tool with many features, so Bufler doesn’t replace it completely. Bufler is a very young project.

Changelog

0.4-pre

This release includes additional support for Emacs’s tab-bar-mode. Basically, commands and features that formerly acted on the current frame now act on the current tab when tab-bar-mode is active, otherwise on the current frame.

Notably, these changes are also designed to facilitate integration with Burly’s burly-tabs-mode (e.g. when a Burly bookmark is opened in a tab-bar tab, the tab’s Bufler workspace can be set to the workspace containing the buffer, so that bufler-switch-buffer automatically offers buffers relevant to the tab).

Note as well that the existing bufler-workspace-workspaces-as-tabs-mode overrides some aspects of Emacs’s tab-bar-mode and tab-line-mode; this functionality is still somewhat experimental and may not suit every user’s taste. But while that mode may remain disabled, Bufler’s other features are still useful with standard tab-bar-mode. (Yes, all these names and modes and features do get confusing. The term “workspaces” is vague, encompassing a variety of ideas envisioned by a range of users. Bufler’s implementation is just one iteration of the concept.)

Additions

Command bufler-workspace-set sets the workspace of the current tab-bar tab or frame.
Option bufler-workspace-switch-buffer-and-tab (enabled by default) automatically switches to a buffer’s workspace’s tab, if it has one, when using bufler-switch-buffer. (This tries to solve the age-old problem of buffers not “staying in their workspace.”)
Commands bufler-workspace-open and bufler-workspace-save. These open and save workspaces using Burly as a backend (which is now a dependency). (This is basically like calling burly-open-bookmark and burly-bookmark-windows, but integrating some bufler-workspace features automatically.)
Option bufler-workspace-prefix-abbreviation, which abbreviates workspace names in tab/frame names.
Option bufler-switch-buffer-include-recent-buffers includes recently shown buffers in the bufler-switch-buffer command’s list of buffers.

Changes

Command bufler-workspace-focus-buffer sets the workspace of the current tab-bar tab or frame to the current buffer’s workspace.
Command bufler-workspace-switch-buffer offers buffers from the workspace of the current tab-bar tab or frame.
Mode bufler-workspace-mode’s mode-line lighter shows the path of the current tab-bar tab or frame.

Fixes

The dir buffer group uses the base buffer’s directory for indirect buffers.
When testing whether two directories are related, both the paths as-given and the canonicalized paths are compared (so that if a subdirectory is a symlink to a directory outside the parent directory, it will still be considered related).

0.3

Added

Group type auto-parent-project.
Option bufler-vc-remote, which controls the displaying of the version control state of remote files (default: off). (Fixes #41. Thanks to Tory S. Anderson for reporting.)
Option bufler-workspace-format-path-fn, which formats group paths for display in mode lines and frame titles (e.g. it may be customized to show just the last element).
Show an asterisk next to buffers with unsaved changes. (Thanks to Tatu Lahtela.)
Name and path columns optionally limit width to that defined in their customization options. (Thanks to Tory S. Anderson.)
Column Mode shows buffer’s major mode, sans -mode suffix.
More filtering options: bufler-filter-buffer-fns, bufler-workspace-switch-buffer-filter-fns, bufler-filter-buffer-modes, and bufler-filter-buffer-name-regexps. By default, more buffers will be hidden in bufler-list and bufler-switch-buffer, and filters may be disabled by calling those commands with universal prefix arguments.
Option bufler-list-display-buffer-action, which controls how the bufler-list buffer is displayed.
Option bufler-list-switch-buffer-action, which controls how buffers are displayed when switched to from the buffer list. (Fixes #76. Thanks to Julian M. Burgos, Tory S. Anderson, and jcalve for reporting.)
Option bufler-indent-per-level, which sets the indentation applied per level of depth.
Command bufler-sidebar displays the Bufler list in a side window.
Project metadata cache (because the project-current function can be slow when called for many paths in rapid succession, as when many buffers are open).

Fixed

Option bufler-filter-buffer-modes had the wrong customization type.
Depend on at least version 2.1 of the map package (required for pcase macro expansion).
Columns’ max-width options. (Fixes #79. Thanks to Tory S. Anderson for reporting.)

Changed

Don’t show *xref* buffers by default.
Command bufler-switch-buffer allows entering a non-existent buffer name to create a buffer and switch to it (like switch-to-buffer).

0.2

Project expanded and renamed from Sbuffer to Bufler.

0.1

First tagged release.

Credits

Thanks to Jonas Bernoulli for magit-section.
Thanks to Magnar Sveen and Matus Goljer for dash.el.
Thanks to Johan Andersson for f.el.
Thanks to Jerry Peng for Pretty Hydra.

Development

Bufler bufler bufler bufler bufler bufler bufler bufler.

License

GPLv3