doomemacs/modules/feature/lookup

feature/lookup

• Table of Contents
• Description
  • Module Flags
  • Plugins
• Install
  • Module flags
  • Dependencies
    • MacOS
    • Arch Linux
• Features
  • Jump to definition
  • Find references
  • Look up documentation
  • Search a specific documentation backend
• Configuration
  • Settings
    • set-lookup-handlers! MODES &rest PLIST
      • Example
    • set-docsets! MODES &rest DOCSETS
  • Open in eww instead of browser
• Appendix
  • Commands

Table of Contents   TOC

• Description

  • Module Flags
  • Plugins

• Install

  • Module flags
  • Dependencies

• Features

  • Jump to definition
  • Find references
  • Look up documentation
  • Search a specific documentation backend

• Configuration

  • Settings
  • Open in eww instead of browser

• Appendix

  • Commands

Description

Integrates with code navigation and documentation tools to help you quickly look up definitions, references and documentation.

• Jump-to-definition and find-references implementations that just work.
• Powerful xref integration for languages that support it.
• Documentation lookup for a variety of online sources (like devdocs.io, stackoverflow or youtube).
• Integration with Dash.app docsets.

Module Flags

• +docsets Enable integration with Dash.app docsets.

Plugins

• dumb-jump
• ivy-xref or helm-xref
• counsel-dash or helm-dash

Install

To enable the module add :feature lookup to your doom! block in ~/.emacs.d/init.el.

Module flags

This module provides two flags:

• +docsets Enables integration with Dash docsets.

Dependencies

This module has several soft dependencies:

• the_silver_searcher and/or ripgrep as a last-resort fallback for jump-to-definition/find-references.
• Optionally, sqlite3 for Dash docset support.

MacOS

brew install the_silver_searcher ripgrep

# An older version of sqlite is included in MacOS. If it causes you problems (and
# it has been reported that it will), install it through homebrew:
brew install sqlite
# Note that it's keg-only, meaning it isn't symlinked to /usr/local/bin. You'll
# have to add it to PATH yourself (or symlink it into your PATH somewhere). e.g.
export PATH="/usr/local/opt/sqlite/bin:$PATH"

Arch Linux

sudo pacman -S sqlite the_silver_searcher ripgrep

Features

Jump to definition

Use +lookup/definition (bound to gd in normal mode) to jump to the definition of the symbol at point

This module provides a goto-definition implementation that will try the following sources before giving up:

1. Whatever :definition function is registered for the current buffer with the :lookup setting (see "Configuration" section).
2. Any available xref backends.
3. dumb-jump (a text search with aides to reduce false positives).
4. An ordinary project-wide text search with ripgrep or the_silver_searcher.
5. If evil-mode is active, use evil-goto-definition, which preforms a simple text search within the current buffer.

If there are multiple results, you will be prompted to select one.

Find references

Use +lookup/references (bound to gD in normal mode) to see a list of references for the symbol at point from throughout your project.

Like +lookup/definition, this tries a number of sources before giving up. It will try:

1. Whatever :references function is registered for the current buffer with the :lookup setting (see "Configuration" section).
2. Any available xref backends.
3. An ordinary project-wide text search with ripgrep or the_silver_searcher.

If there are multiple results, you will be prompted to select one.

Look up documentation

+lookup/documentation (bound to K in normal mode) will open documentation for the symbol at point.

Depending on your configuration, this will try a list of sources:

1. Whatever :documentation function is registered for the current buffer with the :lookup setting (see "Configuration" section).
2. Any Dash.app docsets, if any are installed for the current major mode.
3. devdocs.io, if it has a docset for the current mode.
4. An online search; using the last engine used (it will prompt you the first time, or if current-prefix-arg is non-nil).

Search a specific documentation backend

You can perform a documentation lookup on any backends directly:

• Dash Docsets: +lookup/in-docsets, or :dash QUERY for evil users.
• devdocs.io: +lookup/in-devdocs, or :dd QUERY for evil users.
• Online (generic): +lookup/online or +lookup/online-select (bound to SPC / o), or :lo[okup] QUERY for evil users.

Configuration

Settings

This module provides two setters:

set-lookup-handlers! MODES &rest PLIST

Defines a lookup target for major MODES (one major-mode symbol or a list thereof). PLIST accepts the following optional properties:

:definition FN

Run when jumping to a symbol's definition. Used by +lookup/definition.

:references FN

Run when looking for usage references of a symbol in the current project. Used by +lookup/references.

:documentation FN

Run when looking up documentation for a symbol. Used by +lookup/documentation.

:file FN

Run when looking up the file for a symbol/string. Typically a file path. Used by +lookup/file.

:xref-backend FN

Defines an xref backend for a major-mode. With this, :definition and :references are unnecessary.

Example

;; For python-mode, anaconda-mode offers a backend for all three lookup
;; functions. We can register them like so:
(set-lookup-handlers! 'python-mode
  :definition #'anaconda-mode-find-definitions
  :references #'anaconda-mode-find-references
  :documentation #'anaconda-mode-show-doc)

;; If a language or plugin provides a custom xref backend available for it, use
;; that instead. It will provide the best jump-to-definition and find-references
;; experience. You can specify custom xref backends with:
(set-lookup-handlers! 'js2-mode :xref-backend #'xref-js2-xref-backend)
;; NOTE: xref doesn't provide a :documentation backend.

set-docsets! MODES &rest DOCSETS

Registers DOCSETS (one string or list of strings) for MODES (one major mode symbol or a list of them). It is used by +lookup/in-docsets and +lookup/documentation.

(set-docsets! 'js2-mode "JavaScript" "JQuery")
;; Add docsets to minor modes by starting DOCSETS with :add
(set-docsets! 'rjsx-mode :add "React")
;; Or remove docsets from minor modes
(set-docsets! 'nodejs-mode :remove "JQuery")

Open in eww instead of browser

(setq +lookup-open-url-fn 'eww)

Appendix

Commands

• +lookup/definition
• +lookup/references
• +lookup/documentation
• +lookup/online
• +lookup/online-select
• +lookup/in-devdocs
• +lookup/in-docsets