\input texinfo    @c -*- texinfo -*-
@c %**start of header
@setfilename racket-mode.info
@settitle Racket Mode
@documentencoding UTF-8
@documentlanguage en
@syncodeindex pg cp
@c %**end of header

@dircategory Emacs
@direntry
* Racket Mode: (racket-mode). Edit and REPL major modes for Racket lang.
@end direntry

@finalout
@titlepage
@title Racket Mode
@author Greg Hendershott (@email{racket@@greghendershott.com})
@end titlepage

@contents

@ifnottex
@node Top
@top Racket Mode
@end ifnottex

@menu
* Introduction::
* Install::
* Configure::
* Reference::
* Commands::
* Variables::
* Faces::

@detailmenu
--- The Detailed Node Listing ---

Install

* Configure Emacs to use MELPA::
* Install Racket Mode::
* Minimal Racket::
* Uninstall::
* Update::

Update

* Upgrading all packages::
* Updating just Racket Mode::
Configure

* Key bindings::
* Font-lock (syntax highlighting)::
* Completion::
* Xref (definitions and references)::
* Indent::
* paredit::
* smartparens::
* Edit buffers and REPL buffers::
* eldoc::
* Start faster::
* Unicode input method::
* Ligatures::

Commands

* Edit::
* Explore::
* Run::
* Test::
* Eval::
* Collections::
* Macro expand::
* Other::
* Showing information::
* Associating edit buffers with REPL buffers::
* Browsing file URLs with anchors::

Edit

* racket-mode::
* racket-insert-lambda::
* racket-fold-all-tests::
* racket-unfold-all-tests::
* racket-tidy-requires::
* racket-trim-requires::
* racket-base-requires::
* racket-add-require-for-identifier::
* racket-indent-line::
* racket-smart-open-bracket-mode::
* racket-insert-closing::
* racket-cycle-paren-shapes::
* racket-backward-up-list::
* racket-unicode-input-method-enable::
* racket-align::
* racket-unalign::
* racket-complete-at-point::

Explore

* racket-xp-mode::
* racket-xp-describe::
* racket-xp-documentation::
* racket-xp-next-definition::
* racket-xp-previous-definition::
* racket-xp-next-use::
* racket-xp-previous-use::
* racket-xp-next-error::
* racket-xp-previous-error::
* racket-xp-tail-up::
* racket-xp-tail-down::
* racket-xp-tail-next-sibling::
* racket-xp-tail-previous-sibling::
* racket-documentation-search::
* racket-search-describe::

Run

* racket-repl-mode::
* racket-run::
* racket-run-and-switch-to-repl::
* racket-run-module-at-point::
* racket-repl::
* racket-repl-describe::
* racket-repl-documentation::
* racket-racket::
* racket-profile::
* racket-profile-mode::
* racket-logger::
* racket-logger-mode::
* racket-debug-mode::
* racket-repl-clear::
* racket-repl-clear-leaving-last-prompt::

Test

* racket-test::
* racket-raco-test::

Eval

* racket-send-region::
* racket-send-definition::
* racket-send-last-sexp::

Collections

* racket-open-require-path::
* racket-find-collection::

Macro expand

* racket-stepper-mode::
* racket-expand-file::
* racket-expand-region::
* racket-expand-definition::
* racket-expand-last-sexp::

Other

* racket-mode-start-faster::
* racket-mode-start-slower::

Showing information

* racket-show-pseudo-tooltip::
* racket-show-echo-area::
* racket-show-header-line::
* racket-show-pos-tip::

Associating edit buffers with REPL buffers

* racket-repl-buffer-name-shared::
* racket-repl-buffer-name-unique::
* racket-repl-buffer-name-project::
* racket-project-root::

Browsing file URLs with anchors

* racket-browse-url-using-temporary-file::
Variables

* General variables::
* REPL variables::
* Other variables::
* Experimental debugger variables::
* Showing information: Showing informationx. 

General variables

* racket-program::
* racket-command-timeout::
* racket-memory-limit::
* racket-error-context::
* racket-user-command-line-arguments::
* racket-path-from-emacs-to-racket-function::
* racket-path-from-racket-to-emacs-function::
* racket-browse-url-function::
* racket-xp-after-change-refresh-delay::
* racket-xp-highlight-unused-regexp::
* racket-documentation-search-location::

REPL variables

* racket-repl-buffer-name-function::
* racket-submodules-to-run::
* racket-repl-history-directory::
* racket-history-filter-regexp::
* racket-images-inline::
* racket-imagemagick-props::
* racket-images-keep-last::
* racket-images-system-viewer::
* racket-pretty-print::

Other variables

* racket-indent-curly-as-sequence::
* racket-indent-sequence-depth::
* racket-pretty-lambda::
* racket-smart-open-bracket-enable::
* racket-logger-config::
* racket-before-run-hook::
* racket-after-run-hook::

Experimental debugger variables

* racket-debuggable-files::

Showing information

* racket-show-functions::
Faces

* All::

All

* racket-keyword-argument-face::
* racket-selfeval-face::
* racket-here-string-face::
* racket-xp-def-face::
* racket-xp-use-face::
* racket-xp-unused-face::
* racket-xp-tail-target-face::
* racket-xp-tail-position-face::
* racket-logger-config-face::
* racket-logger-topic-face::
* racket-logger-fatal-face::
* racket-logger-error-face::
* racket-logger-warning-face::
* racket-logger-info-face::
* racket-logger-debug-face::
@end detailmenu
@end menu



@node Introduction
@chapter Introduction

The @uref{https://www.racket-mode.com/,Racket Mode} package consists of a variety of Emacs major and minor modes, including:

@itemize
@item
@code{racket-mode}: A major mode for editing @code{.rkt} files.

@item
@ref{racket-xp-mode}: An optional minor mode that enhances @code{racket-mode} to explain and explore code.

@item
@code{racket-repl-mode}: A major mode for running programs providing a REPL.

@item
Various other modes to support specific features:
@itemize
@item
@ref{racket-logger-mode}
@item
@ref{racket-profile-mode}
@item
@ref{racket-debug-mode}
@end itemize
@end itemize

Racket Mode uses a ``back end server'' written in Racket, which is responsible for running files and implementing commands that cannot be implemented in Emacs Lisp.@footnote{Racket Mode's Racket code is also delivered as part of the Emacs package --- @emph{not} as a Racket package. Delivering both Emacs and Racket code in one Emacs package simplifies installation and updates. The main drawback is that the Racket code is not automatically byte-compiled, as would normally be done by @code{raco pkg install}. To address this: @xref{racket-mode-start-faster}.}

For code, issues, and pull requests, see the @uref{https://github.com/greghendershott/racket-mode,Git repo}.

To fund this work, see @uref{https://github.com/users/greghendershott/sponsorship,GitHub Sponsors} or @uref{https://www.paypal.me/greghendershott,PayPal}.

@node Install
@chapter Install

The recommended way to use Racket Mode is to install the package from @uref{https://melpa.org/#/racket-mode,MELPA}.
@menu
* Configure Emacs to use MELPA::
* Install Racket Mode::
* Minimal Racket::
* Uninstall::
* Update::
@end menu

@node Configure Emacs to use MELPA
@section Configure Emacs to use MELPA

To use MELPA:

@itemize
@item
Add the following to your @verb{,~/.emacs,} or @verb{,~/.emacs.d/init.el,}:
@end itemize

@lisp
(require 'package)
(add-to-list 'package-archives
	      '("melpa" . "https://melpa.org/packages/")
	      t)
@end lisp

@itemize
@item
Restart Emacs.

@item
Type @kbd{M-x}  @code{package-refresh-contents} @kbd{RET} .
@end itemize

@node Install Racket Mode
@section Install Racket Mode

When Emacs is configured to use MELPA, simply type @kbd{M-x}  @code{package-install} @kbd{RET}  @code{racket-mode} @kbd{RET} .

@node Minimal Racket
@section Minimal Racket

If you have installed the minimal Racket distribution (for example by using the @uref{https://github.com/Homebrew/homebrew-core/blob/master/Formula/minimal-racket.rb,homebrew formula}) Racket Mode needs some additional packages (like @code{errortrace} and @code{macro-debugger}). A simple way to get all these packages is to install the @code{drracket} Racket package. In a command shell:

@example
raco pkg install drracket
@end example

@node Uninstall
@section Uninstall

To uninstall Racket Mode, simply type @kbd{M-x}  @code{package-delete} @kbd{RET}  @code{racket-mode} @kbd{RET} .

You should probably also exit and restart Emacs.

@node Update
@section Update

@menu
* Upgrading all packages::
* Updating just Racket Mode::
@end menu

@node Upgrading all packages
@subsection Upgrading all packages

The ``easy path'' provided by Emacs is to update @emph{all} packages to their latest versions. Although you might not want to do this --- see next section --- here is how to do so:

@enumerate
@item
Use @kbd{M-x}  @code{list-packages}. It should display a message like ``42 packages can be upgraded; type ‘U’ to mark them for upgrading.''.

@item
Press @kbd{U}  as suggested to mark them all.

@item
Press @kbd{x}  to execute.
@end enumerate

After such a mass update, it might be wise to exist restart Emacs.

@node Updating just Racket Mode
@subsection Updating just Racket Mode

Updating all packages sometimes is more than you want. For example, maybe you will discover that some packages have changed in ways that require you to take time to learn about, change customizations, and so on.

To update just Racket Mode:

@enumerate
@item
Uninstall Racket Mode: @kbd{M-x}  @code{package-delete} @kbd{RET}  @code{racket-mode} @kbd{RET} .

@item
Optional but most reliable: Exit and restart Emacs.

@item
Install Racket Mode: @kbd{M-x}  @code{package-install} @kbd{RET}  @code{racket-mode} @kbd{RET} . This will install the latest version.
@end enumerate

@node Configure
@chapter Configure

Although Racket Mode can be customized with many @ref{Variables}, there is only one that you might @emph{need} to set: @ref{racket-program}. This is the name or pathname of the Racket executable. It defaults to @code{Racket.exe} on Windows else @code{racket}.

On Windows or Linux, this default will probably work for you.

On macOS, downloading Racket doesn't add its @code{bin} directory to your @code{PATH}. Even after you add it, GUI Emacs doesn't automatically use your path (unless you use the handy @uref{https://melpa.org/#/exec-path-from-shell,exec-path-from-shell} package). Therefore you might want to set @code{racket-program} to a complete pathname.

You can @code{setq} this directly in your Emacs init file (@verb{,~/.emacs,} or @verb{,~/.emacs.d/init.el,}), or, use @kbd{M-x}  @code{customize}, as you prefer.
@menu
* Key bindings::
* Font-lock (syntax highlighting)::
* Completion::
* Xref (definitions and references)::
* Indent::
* paredit::
* smartparens::
* Edit buffers and REPL buffers::
* eldoc::
* Start faster::
* Unicode input method::
* Ligatures::
@end menu

@node Key bindings
@section Key bindings

To customize things like key bindings, you can use @code{racket-mode-hook} in your Emacs init file to modify @code{racket-mode-map}. For example, although @kbd{C-c C-c}  is bound by default to the @code{racket-run} command, let's say you wanted @kbd{F5}  to be an additional binding:

@lisp
(add-hook 'racket-mode-hook
	  (lambda ()
	    (define-key racket-mode-map (kbd "<f5>") 'racket-run)))
@end lisp

Likewise for @code{racket-repl-mode-hook} and @code{racket-repl-mode-map}.

@node Font-lock (syntax highlighting)
@section Font-lock (syntax highlighting)

Font-lock (as Emacs calls syntax highlighting) can be controlled using the variable @code{font-lock-maximum-decoration}, which defaults to @code{t} (maximum). You can set it to a number, where @code{0} is the lowest level. You can even supply an association list to specify different values for different major modes.

Historically you might choose a lower level for speed. These days you might do so because you prefer a simpler appearance.

Racket Mode supports four, increasing levels of font-lock:

@itemize
@item
@code{0}: Just strings, comments, and @code{#lang}.
@item
@code{1}: @code{#:keyword} and self-evaluating literals like numbers, quoted symbols (including symbols with spaces delimited by @code{|} characters), and @code{#rx} and @code{#px} regular expressions.
@item
@code{2}: Identifiers in @code{define}-like and @code{let}-like forms.
@item
@code{3}: Identifiers provided by @code{racket}, @code{typed/racket}, @code{racket/syntax}, and @code{syntax/parse}. (This level effectively treats Racket as a language, instead of a language for making languages.).
@end itemize

@node Completion
@section Completion

In Emacs, a major mode may supply a ``completion-at-point function''. This function is used by manual completion commands like @code{complete-symbol} (bound by default to @kbd{C-M-i} ), as well as by auto-completion packages like @code{company-mode}.

@itemize
@item
@code{racket-mode} supplies @code{racket-complete-at-point}, which simply supplies the same symbols that it knows how to font-lock. This does @emph{not} require the Racket Mode back end to be running. But of course the completion candidates do not correspond to your program's definitions or those it imports. This is a static, ``better than nothing'' fallback.

@item
@code{racket-xp-mode} --- an optional minor mode that enhances @code{racket-mode} --- supplies @code{racket-xp-complete-at-point}, which uses a static analysis to find local and imported binding names. Although this requires the Racket Mode back end to be running --- and will automatically start it --- it does @emph{not} require the edit buffer to be @code{racket-run}.

@item
@code{racket-repl-mode} supplies @code{racket-repl-complete-at-point}, which uses the result of @code{namespace-mapped-symbols} on the program currently running in the REPL.
@end itemize

These completion functions are set by default. (However, @code{racket-xp-mode} is not enabled by default. To do so: @ref{racket-xp-mode}.)

If you want @kbd{TAB}  to do completion as well as indent, add the following to your Emacs init file:

@lisp
(setq tab-always-indent 'complete)
@end lisp

This changes the behavior of Emacs' standard @code{indent-for-tab-command}, to which @kbd{TAB}  is bound by default in @code{racket-mode} and @code{racket-repl-mode}.

@node Xref (definitions and references)
@section Xref (definitions and references)

Several modes support the Emacs commands

@itemize
@item
@kbd{M-.}  @code{xref-find-definitions}
@item
@kbd{M-?}  @code{xref-find-references}
@item
@kbd{M-,}  @code{xref-pop-marker-stack}
@end itemize

To do so, each mode adds a local hook for @code{xref-backend-functions}:

@itemize
@item
@ref{racket-mode}: @code{#'racket-mode-xref-backend-function}
@item
@ref{racket-xp-mode}: @code{#'racket-xp-xref-backend-function}
@item
@ref{racket-repl-mode}: @code{#'racket-repl-xref-backend-function}
@end itemize

If you prefer, you can remove the local hook --- e.g. for @code{racket-mode}: @code{(remove-hook 'xref-backend-functions #'racket-mode-xref-function t)}.

You can @code{M-x customize-group} and enter @code{xref} to adjust some other settings. For example, the customization variable @code{xref-prompt-for-identifier} controls which commands prompt you and when. You might prefer to set it to @code{nil}.

If you use @code{paredit}, by default it binds @kbd{M-?}  to @code{paredit-convolute-sexp}. You can change that binding in @code{paredit-mode-map} allowing the global binding for @kbd{M-?}  to be used, or, pick some other key for @code{xref-find-references} in the global map.

Finally, what to expect:

@itemize
@item
Racket does not have a global or project-wide database of definitions and references.
@item
Various modules can export identifiers with the same symbolic value -- for example a different ``define'' is provided by @code{racket/base}, @code{typed/racket/base}, and other modules.
@item
A module can import something, then rename, contract, and re-export it.
@end itemize

As a result, to find a definition, it is necessary to know exactly @emph{which} identifier is meant --- either by expanding the module (as is done by @code{racket-xp-mode}) or by actually running it (@code{racket-repl-mode}). Once known, we can usually find the definition site, even through a chain of renaming and/or contract-wrapping exports. In addition, when point is on a module within  @code{require} form, we can usually find the source file. (In plain @code{racket-mode} edit buffers not enhanced by @code{racket-xp-mode}, the only thing that @code{xref-find-definitions} does is visit relative requires, e.g. @code{foo.rkt} in @code{(require "foo.rkt")}.)

As for finding references, the default xref implementation is used, which greps for strings among a project's files. Although @code{racket-xp-mode} can sometimes do better, using @code{drracket/check-syntax} for definitions and references @emph{within} the current buffer, beyond those it also falls back to the default implementation.

In any case, using the Emacs xref API allows for consistent command names, shortcut keys, and even a special buffer to navigate among references and visit each source location.

@node Indent
@section Indent

Indentation can be customized in a way similar to lisp-mode and scheme-mode: @ref{racket-indent-line}.

@node paredit
@section paredit

If you use @uref{https://melpa.org/#/paredit,paredit}, you might want to add keybindings to @code{paredit-mode-map}:

@itemize
@item
Bind the curly brace keys to @code{paredit-open-curly} and @code{paredit-close-curly}.

@item
Bind whatever keys you prefer for @code{paredit-wrap-square} and @code{paredit-wrap-curly}.
@end itemize

For example, with @uref{https://melpa.org/#/use-package,@code{use-package}}:

@lisp
(use-package paredit
  :ensure t
  :config
  (dolist (m '(emacs-lisp-mode-hook
	       racket-mode-hook
	       racket-repl-mode-hook))
    (add-hook m #'paredit-mode))
  (bind-keys :map paredit-mode-map
	     ("@{"   . paredit-open-curly)
	     ("@}"   . paredit-close-curly))
  (unless terminal-frame
    (bind-keys :map paredit-mode-map
	       ("M-[" . paredit-wrap-square)
	       ("M-@{" . paredit-wrap-curly))))
@end lisp

@node smartparens
@section smartparens

If instead of paredit you prefer @uref{https://melpa.org/#/smartparens,smartparens}, you can use the default configuration it provides for Lisp modes generally and for Racket Mode specifically:

@lisp
(require 'smartparens-config)
@end lisp

@node Edit buffers and REPL buffers
@section Edit buffers and REPL buffers

By default, all @code{racket-mode} edit buffers share one @code{racket-repl-mode} buffer, named @code{*Racket REPL*}. For example, if you run foo.rkt, the REPL prompt changes to @code{foo.rkt>}, and the REPL is inside the file module namespace. If you then run bar.rkt, the REPL prompt changes to @code{bar.rkt>}, and you are in that namespace.

If you prefer, you can use more than one REPL buffer, by customizing the variable @ref{racket-repl-buffer-name-function}:

@itemize
@item
Share a REPL buffer among files belonging to the same project; each REPL buffer is named @code{*Racket REPL <project-name>*}.
@item
A unique REPL buffer for each edit buffer, similar to Dr Racket; each REPL buffer is named @code{*Racket REPL <file.rkt>*}.
@item
You can also define your own, custom function.
@end itemize

You can customize where the REPL buffer is displayed by adding an item to the Emacs variable @code{display-buffer-alist}. A good regular expression to use for this would be @code{\\`\\*Racket REPL}. For example, if you wanted to make the REPL buffer appear in a new frame:

@lisp
(add-to-list 'display-buffer-alist
	     '("\\`\\*Racket REPL"
	       (display-buffer-reuse-window
		display-buffer-pop-up-frame)
	       (reusable-frames . 0)
	       (inhibit-same-window . t)))
@end lisp

@node eldoc
@section eldoc

By default Racket Mode sets @code{eldoc-documentation-function} to @code{nil} --- no @code{eldoc-mode} support. You may set it to @code{racket-eldoc-function} in a @code{racket-mode-hook} and @code{racket-repl-mode-hook} if you really want to use @code{eldoc-mode} with Racket. But it is not a very satisfying experience because Racket is not a very ``eldoc-friendly'' language. Although Racket Mode attempts to discover argument lists, contracts, or types this doesn't work in many common cases:

@itemize
@item
Many Racket primitives are defined in @code{#%kernel} or @code{#%runtime}. There's no easy way to determine their argument lists. Most do not @code{provide} a contract.

@item
Many of the interesting Racket forms are syntax (macros) not functions. There's no easy way to determine their ``argument lists''.

@item
When a form has documentation, Racket Mode can show the \"bluebox\'' -- but often that does not fit in a single line as you would normally expect with eldoc.
@end itemize

A more satisfying experience is to use @ref{racket-xp-describe} or @ref{racket-xp-documentation}.

@node Start faster
@section Start faster

You can use @ref{racket-mode-start-faster} to make the Racket REPL start faster.

@node Unicode input method
@section Unicode input method

An optional Emacs input method, @code{racket-unicode}, lets you easily type various Unicode symbols that might be useful when writing Racket code.

To automatically enable the @code{racket-unicode} input method in @code{racket-mode} and @code{racket-repl-mode} buffers, put the following code in your Emacs init file:

@lisp
(add-hook 'racket-mode-hook      #'racket-unicode-input-method-enable)
(add-hook 'racket-repl-mode-hook #'racket-unicode-input-method-enable)
@end lisp

@xref{racket-unicode-input-method-enable}.

@xref{racket-insert-lambda}.

@node Ligatures
@section Ligatures

Prior to Emacs 28.0.50, things like @code{auto-composition-mode} or @code{ligature-mode} that use @code{composition-function-table} to display ligatures can cause Emacs to freeze. This can happen when an Emacs @code{overlay} displays a string containing such a ligature --- this includes the overlays created by @code{racket-show-pseudo-tooltip}, as used by @code{racket-xp-mode}. The only known work-around is to change the value of @code{racket-show-functions} to something ``boring'' such as @code{(racket-show-echo-area)}.

@node Reference
@chapter Reference

The following sections are generated from the doc strings for each command, variable, or face. (As a result, some of the formatting might not be quite as nice or correct as in the previous sections.)

You can also view these by using the normal Emacs help mechanism:

@itemize
@item
@kbd{C-h f}  and enter the name of a command.
@item
@kbd{C-h v}  and enter the name of a variable.
@end itemize

@node Commands
@chapter Commands

@menu
* Edit::
* Explore::
* Run::
* Test::
* Eval::
* Collections::
* Macro expand::
* Other::
* Showing information::
* Associating edit buffers with REPL buffers::
* Browsing file URLs with anchors::
@end menu

@node Edit
@section Edit

@menu
* racket-mode::
* racket-insert-lambda::
* racket-fold-all-tests::
* racket-unfold-all-tests::
* racket-tidy-requires::
* racket-trim-requires::
* racket-base-requires::
* racket-add-require-for-identifier::
* racket-indent-line::
* racket-smart-open-bracket-mode::
* racket-insert-closing::
* racket-cycle-paren-shapes::
* racket-backward-up-list::
* racket-unicode-input-method-enable::
* racket-align::
* racket-unalign::
* racket-complete-at-point::
@end menu

@node racket-mode
@subsection racket-mode

@kbd{M-x}  @code{racket-mode}

Major mode for editing Racket source files.

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{@}} 
@tab @ref{racket-insert-closing}
@item @kbd{]} 
@tab @ref{racket-insert-closing}
@item @kbd{)} 
@tab @ref{racket-insert-closing}
@item @kbd{TAB} 
@tab @code{indent-for-tab-command}
@item @kbd{C-x C-e} 
@tab @ref{racket-send-last-sexp}
@item @kbd{C-M-y} 
@tab @ref{racket-insert-lambda}
@item @kbd{C-M-u} 
@tab @ref{racket-backward-up-list}
@item @kbd{C-M-x} 
@tab @ref{racket-send-definition}
@item @kbd{C-c C-u} 
@tab @ref{racket-unfold-all-tests}
@item @kbd{C-c C-f} 
@tab @ref{racket-fold-all-tests}
@item @kbd{C-c C-d} 
@tab @ref{racket-documentation-search}
@item @kbd{C-c C-p} 
@tab @ref{racket-cycle-paren-shapes}
@item @kbd{C-c C-x C-f} 
@tab @ref{racket-open-require-path}
@item @kbd{C-c C-e r} 
@tab @ref{racket-expand-region}
@item @kbd{C-c C-e e} 
@tab @ref{racket-expand-last-sexp}
@item @kbd{C-c C-e x} 
@tab @ref{racket-expand-definition}
@item @kbd{C-c C-e f} 
@tab @ref{racket-expand-file}
@item @kbd{C-c C-r} 
@tab @ref{racket-send-region}
@item @kbd{C-c C-o} 
@tab @ref{racket-profile}
@item @kbd{C-c C-l} 
@tab @ref{racket-logger}
@item @kbd{C-c C-t} 
@tab @ref{racket-test}
@item @kbd{C-c C-z} 
@tab @ref{racket-repl}
@item @kbd{C-c C-k} 
@tab @ref{racket-run-module-at-point}
@item @kbd{C-c C-c} 
@tab @ref{racket-run-module-at-point}
@end multitable



In addition to any hooks its parent mode @code{prog-mode} might have run,
this mode runs the hook @code{racket-mode-hook}, as the final step
during initialization.

@node racket-insert-lambda
@subsection racket-insert-lambda

@kbd{C-M-y} 

Insert λ.

To insert Unicode symbols generally, see @ref{racket-unicode-input-method-enable}.

@node racket-fold-all-tests
@subsection racket-fold-all-tests

@kbd{C-c C-f} 

Fold (hide) all test submodules.

@node racket-unfold-all-tests
@subsection racket-unfold-all-tests

@kbd{C-c C-u} 

Unfold (show) all test submodules.

@node racket-tidy-requires
@subsection racket-tidy-requires

@kbd{M-x}  @code{racket-tidy-requires}

Make a single ``require'' form, modules sorted, one per line.

The scope of this command is the innermost module around point,
including the outermost module for a file using a ``#lang'' line.
All require forms within that module are combined into a single
form. Within that form:

@itemize
@item
A single subform is used for each phase level, sorted in this
order: for-syntax, for-template, for-label, for-meta, and
plain (phase 0).

@itemize
@item
Within each level subform, the modules are sorted:

@itemize
@item
Collection path modules -- sorted alphabetically.

@item
Subforms such as only-in.

@item
Quoted relative requires -- sorted alphabetically.
@end itemize
@end itemize
@end itemize

At most one required module is listed per line.

See also: @ref{racket-trim-requires} and @ref{racket-base-requires}.

@node racket-trim-requires
@subsection racket-trim-requires

@kbd{M-x}  @code{racket-trim-requires}

Like @ref{racket-tidy-requires} but also deletes unnecessary requires.

Note: This only works when the source file can be fully expanded
with no errors.

Note: This only works for requires at the top level of a source
file using #lang. It does NOT work for require forms inside
module forms. Furthermore, it is not smart about module+ or
module* forms -- it might delete top level requires that are
actually needed by such submodules.

See also: @ref{racket-base-requires}.

@node racket-base-requires
@subsection racket-base-requires

@kbd{M-x}  @code{racket-base-requires}

Change from ``#lang racket'' to ``#lang racket/base''.

Adds explicit requires for imports that are provided by
``racket'' but not by ``racket/base''.

This is a recommended optimization for Racket applications.
Avoiding loading all of ``racket'' can reduce load time and
memory footprint.

Also, as does @ref{racket-trim-requires}, this removes unneeded
modules and tidies everything into a single, sorted require form.

Note: This only works when the source file can be fully expanded
with no errors.

Note: This only works for requires at the top level of a source
file using #lang. It does NOT work for require forms inside
module forms. Furthermore, it is not smart about module+ or
module* forms -- it might delete top level requires that are
actually needed by such submodules.

Note: Currently this only helps change ``#lang racket'' to
``#lang racket/base''. It does not help with other similar
conversions, such as changing ``#lang typed/racket'' to ``#lang
typed/racket/base''.

@node racket-add-require-for-identifier
@subsection racket-add-require-for-identifier

@kbd{M-x}  @code{racket-add-require-for-identifier}

Add a require for the identifier at point.

When more than one module supplies an identifer with the same
name, they are listed for you to choose one. The list is sorted
alphabetically, except modules starting with ``racket/'' and
``typed/racket/'' are sorted before others. While at the prompt,
as a convenience you can press C-h to see the ``Search Manuals''
page for locally installed packages -- effectively like
doing ``raco doc'' at the command line.

A ``require'' form is inserted into the buffer, followed by doing
a @ref{racket-tidy-requires}.

Caveat: This works in terms of identifiers that are documented.
The mechanism is similar to that used for Racket's ``Search
Manuals'' feature. Today there exists no system-wide database of
identifiers that are exported but not documented.

@node racket-indent-line
@subsection racket-indent-line

@kbd{M-x}  @code{racket-indent-line}

Indent current line as Racket code.

Normally you don't need to use this command directly, it is used
automatically when you press keys like RET or TAB. However you
might refer to it when configuring custom indentation, explained
below.

This behaves like @code{lisp-indent-line}, except that whole-line
comments are treated the same regardless of whether they start
with single or double semicolons.

@itemize
@item
Automatically indents forms that start with ``begin'' in the
usual way that ``begin'' is indented.

@item
Automatically indents forms that start with ``def'' or
``with-'' in the usual way that ``define'' is indented.

@item
Has rules for many specific standard Racket forms.
@end itemize

To extend, use your Emacs init file to

@example
(put SYMBOL 'racket-indent-function INDENT)
@end example

SYMBOL is the name of the Racket form like ``'test-case'' and
INDENT is an integer or the symbol ``'defun''. When INDENT is an
integer, the meaning is the same as for lisp-indent-function and
scheme-indent-function: Indent the first INDENT arguments
specially and indent any further arguments like a body.

For example:

@example
(put 'test-case 'racket-indent-function 1)
@end example

This will change the indent of @code{test-case} from this:

@example
(test-case foo
	   blah
	   blah)
@end example

to this:

@example
(test-case foo
  blah
  blah)
@end example

If @code{racket-indent-function} has no property for a symbol,
scheme-indent-function is also considered, although the ``with-''
indents defined by scheme-mode are ignored. This is only to help
people who may have extensive scheme-indent-function settings,
particularly in the form of file or dir local variables.
Otherwise prefer putting properties on @code{racket-indent-function}.

@node racket-smart-open-bracket-mode
@subsection racket-smart-open-bracket-mode

@kbd{M-x}  @code{racket-smart-open-bracket-mode}

Minor mode to let you always type @code{[}' to insert @code{(} or @code{[} automatically.

Behaves like the ``Automatically adjust opening square brackets''
feature in Dr. Racket.

By default, inserts a @code{(}. Inserts a @code{[} in the following cases:

@itemize
@item
@code{let}-like bindings -- forms with @code{let} in the name as well
as things like @code{parameterize}, @code{with-handlers}, and
@code{with-syntax}.

@item
@code{case}, @code{cond}, @code{match}, @code{syntax-case}, @code{syntax-parse}, and
@code{syntax-rules} clauses.

@item
@code{for}-like bindings and @code{for/fold} accumulators.

@item
@code{class} declaration syntax, such as @code{init} and @code{inherit}.
@end itemize

When the previous s-expression in a sequence is a compound
expression, uses the same kind of delimiter.

To force insert @code{[}, use @code{quoted-insert}.

Combined with @ref{racket-insert-closing} this means that you can
press the unshifted @code{[} and @code{]} keys to get whatever delimiters
follow the Racket conventions for these forms. When something
like @code{electric-pair-mode} or @code{paredit-mode} is active, you need
not even press @code{]}.

Tip: When also using @code{paredit-mode}, enable that first so that
the binding for the @code{[}' key in the map for
@ref{racket-smart-open-bracket-mode} has higher priority. See also
the variable @code{minor-mode-map-alist}.

@node racket-insert-closing
@subsection racket-insert-closing

@kbd{]}  or @kbd{)} 

Insert a matching closing delimiter.

With @kbd{C-u}  insert the typed character as-is.

This is handy if you're not yet using something like
@code{paredit-mode}, @code{smartparens-mode}, @code{parinfer-mode}, or simply
@code{electric-pair-mode} added in Emacs 24.5.

@node racket-cycle-paren-shapes
@subsection racket-cycle-paren-shapes

@kbd{C-c C-p} 

Cycle the sexpr among () [] @{@}.

@node racket-backward-up-list
@subsection racket-backward-up-list

@kbd{C-M-u} 

Like @code{backward-up-list} but works when point is in a string or comment.

Typically you should not use this command in Emacs Lisp --
especially not repeatedly. Instead, initially use
@code{racket--escape-string-or-comment} to move to the start of a
string or comment, if any, then use normal @code{backward-up-list}
repeatedly.

@node racket-unicode-input-method-enable
@subsection racket-unicode-input-method-enable

@kbd{M-x}  @code{racket-unicode-input-method-enable}

Set input method to racket-unicode.

The racket-unicode input method lets you easily type various
Unicode symbols that might be useful when writing Racket code.

To automatically enable the racket-unicode input method in
racket-mode and racket-repl-mode buffers, put the following code
in your Emacs init file:

@lisp
(add-hook 'racket-mode-hook #'racket-unicode-input-method-enable)
(add-hook 'racket-repl-mode-hook #'racket-unicode-input-method-enable)
@end lisp

To temporarily enable this input method for a single buffer you
can use ``M-x racket-unicode-input-method-enable''.

Use the standard Emacs key C-\ to toggle the input method.

When the racket-unicode input method is active, you can for
example type ``All'' and it is immediately replaced with ``∀''. A
few other examples:

@multitable {aaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaa}
@item omega
@tab ω
@item x@math{_1}
@tab x₁
@item x@math{^1}
@tab x¹
@item A
@tab 𝔸
@item test-->>E
@tab test-->>∃ (racket/redex)
@item vdash
@tab ⊢
@end multitable

To see a table of all key sequences use ``M-x
describe-input-method <RET> racket-unicode''.

If you want to add your own mappings to the ``racket-unicode''
input method, you may add code like the following example in your
Emacs init file:

@lisp
;; Either (require 'racket-mode) here, or, if you use
;; use-package, put the code below in the :config section.
(with-temp-buffer
  (racket-unicode-input-method-enable)
  (set-input-method "racket-unicode")
  (let ((quail-current-package (assoc "racket-unicode"
				      quail-package-alist)))
    (quail-define-rules ((append . t))
			("^o" ["ᵒ"]))))
@end lisp

If you don’t like the highlighting of partially matching tokens you
can turn it off by setting @code{input-method-highlight-flag} to nil.

@node racket-align
@subsection racket-align

@kbd{M-x}  @code{racket-align}

Align values in the same column.

Useful for binding forms like ``let'' and ``parameterize'',
conditionals like ``cond'' and ``match'', association lists, and
any series of couples like the arguments to ``hash''.

Before choosing this command, put point on the first of a series
of ``couples''. A couple is:

@itemize
@item
A list of two or more sexprs: "[sexpr val sexpr @dots{}]".
@item
Two sexprs: ``sexpr val''.
@end itemize

Each ``val'' moves to the same column and is
@code{prog-indent-sexp}-ed (in case it is a multi-line form).

For example with point on the "[" before ``a'':

@example
Before             After

(let ([a 12]       (let ([a   12]
      [bar 23])          [bar 23])
  ....)              ....)

'([a . 12]         '([a   . 12]
  [bar . 23])        [bar . 23])

(cond [a? #t]      (cond [a?   #t]
      [b? (f x           [b?   (f x
	     y)]                  y)]
      [else #f])         [else #f])
@end example

Or with point on the quote before ``a'':

@example
(list 'a 12        (list 'a   12
      'bar 23)           'bar 23)
@end example

If more than one couple is on the same line, none are aligned,
because it is unclear where the value column should be. For
example the following form will not change; @ref{racket-align} will
display an error message:

@example
(let ([a 0][b 1]
      [c 2])       error; unchanged
  ....)
@end example

When a couple's sexprs start on different lines, that couple is
ignored. Other, single-line couples in the series are aligned as
usual. For example:

@example
(let ([foo         (let ([foo
       0]                 0]
      [bar 1]            [bar 1]
      [x 2])             [x   2])
  ....)              ....)
@end example

See also: @ref{racket-unalign}.

@node racket-unalign
@subsection racket-unalign

@kbd{M-x}  @code{racket-unalign}

The opposite of @ref{racket-align}.

Effectively does M-x @code{just-one-space} and @code{prog-indent-sexp} for
each couple's value.

@node racket-complete-at-point
@subsection racket-complete-at-point

A value for the variable @code{completion-at-point-functions}.

Completion candidates are drawn from the same symbols used for
font-lock. This is a static list. If you want dynamic, smarter
completion candidates, enable the minor mode @ref{racket-xp-mode}.

@node Explore
@section Explore

@menu
* racket-xp-mode::
* racket-xp-describe::
* racket-xp-documentation::
* racket-xp-next-definition::
* racket-xp-previous-definition::
* racket-xp-next-use::
* racket-xp-previous-use::
* racket-xp-next-error::
* racket-xp-previous-error::
* racket-xp-tail-up::
* racket-xp-tail-down::
* racket-xp-tail-next-sibling::
* racket-xp-tail-previous-sibling::
* racket-documentation-search::
* racket-search-describe::
@end menu

@node racket-xp-mode
@subsection racket-xp-mode

@kbd{M-x}  @code{racket-xp-mode}

A minor mode that analyzes expanded code to explain and explore.

This minor mode is an optional enhancement to @ref{racket-mode} edit
buffers. Like any minor mode, you can turn it on or off for a
specific buffer. If you always want to use it, put the following
code in your Emacs init file:

@lisp
(require 'racket-xp)
(add-hook 'racket-mode-hook #'racket-xp-mode)
@end lisp

Note: This mode won't do anything unless/until the Racket Mode
back end is running. It will try to start the back end
automatically. You do @emph{not} need to @ref{racket-run} the buffer you
are editing.

This mode uses the drracket/check-syntax package to analyze
fully-expanded programs, without needing to evaluate a.k.a.
``run'' them. The resulting analysis provides information for:

@itemize
@item
Visually annotating bindings -- local or imported definitions
and references to them.

@item
Visually annotating expressions in a tail position, as well as
the enclosing expression with respect to which they are in a
tail position.

@item
Completion candidates.

@item
Defintions' source and documentation.
@end itemize

When point is on a definition or use, related items are
highlighted using @ref{racket-xp-def-face} and @ref{racket-xp-use-face}
-- instead of drawing arrows as in Dr Racket. Information is
displayed using the function(s) in the hook variable
@ref{racket-show-functions}; it is also available when hovering the
mouse cursor.

Note: If you find these point-motion features too distracting
and/or slow, in your @code{racket-xp-mode-hook} you may disable them:

@lisp
(require 'racket-xp)
(add-hook 'racket-xp-mode-hook
	  (lambda ()
	    (remove-hook 'pre-redisplay-functions
			 #'racket-xp-pre-redisplay
			 t)))
@end lisp

The remaining features discussed below will still work.

You may also use commands to navigate among a definition and its
uses, or to rename a local definitions and all its uses:

@itemize
@item
@ref{racket-xp-next-definition}
@item
@ref{racket-xp-previous-definition}
@item
@ref{racket-xp-next-use}
@item
@ref{racket-xp-previous-use}
@end itemize

In the following little example, not only does
drracket/check-syntax distinguish the various ``x'' bindings, it
understands the two different imports of ``define'':

@example
#lang racket/base
(define x 1)
x
(let ([x x])
  (+ x 1))
(module m typed/racket/base
  (define x 2)
  x)
@end example

When point is on the opening parenthesis of an expression in tail
position, it is highlighted using the face
@ref{racket-xp-tail-position-face}.

When point is on the opening parenthesis of an enclosing
expression with respect to which one or more expressions are in
tail position, it is highlighted using the face
@ref{racket-xp-tail-target-face}.

Furthermore, when point is on the opening parenthesis of either
kind of expression, all of the immediately related expressions
are also highlighted. Various commands move among them:

@itemize
@item
@ref{racket-xp-tail-up}
@item
@ref{racket-xp-tail-down}
@item
@ref{racket-xp-tail-next-sibling}
@item
@ref{racket-xp-tail-previous-sibling}
@end itemize

The function @code{racket-xp-complete-at-point} is added to the
variable @code{completion-at-point-functions}. Note that in this case,
it is not smart about submodules; identifiers are assumed to be
definitions from the file's module or its imports. In addition to
supplying completion candidates, it supports the
``:company-location'' property to inspect the definition of a
candidate and the ``:company-doc-buffer'' property to view its
documentation.

When you edit the buffer, existing annotations are retained;
their positions are updated to reflect the edit. Annotations for
new or deleted text are not requested until after
@ref{racket-xp-after-change-refresh-delay} seconds. The request is
made asynchronously so that Emacs will not block -- for
moderately complex source files, it can take some seconds simply
to fully expand them, as well as a little more time for the
drracket/check-syntax analysis. When the results are ready, all
annotations for the buffer are completely refreshed.

You may also set @ref{racket-xp-after-change-refresh-delay} to nil
and use the @code{racket-xp-annotate} command manually.

The mode line changes to reflect the current status of
annotations, and whether or not you had a syntax error.

If you have one or more syntax errors, @ref{racket-xp-next-error} and
@ref{racket-xp-previous-error} navigate among them. Although most
languages will stop after the first syntax error, some like Typed
Racket will try to collect and report multiple errors.

You may use @code{xref-find-definitions} @kbd{M-.} ,
@code{xref-pop-marker-stack} @kbd{M-,} , and
@code{xref-find-references}: @ref{racket-xp-mode} adds a backend to the
variable @code{xref-backend-functions}. This backend uses information
from the drracket/check-syntax static analysis. Its ability to
find references is limited to the current file; when it finds
none it will try the default xref backend implementation which is
grep-based.

Tip: This mode follows the convention that a minor mode may only
use a prefix key consisting of ``C-c'' followed by a punctuation
key. As a result, @code{racket-xp-control-c-hash-keymap} is bound to
``C-c #'' by default. Although you might find this awkward to
type, remember that as an Emacs user, you are free to bind this
map to a more convenient prefix, and/or bind any individual
commands directly to whatever keys you prefer.

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{M-.} 
@tab @code{xref-find-definitions}
@item @kbd{C-c C-d} 
@tab @ref{racket-xp-documentation}
@item @kbd{C-c C-.} 
@tab @ref{racket-xp-describe}
@item @kbd{C-c # P} 
@tab @ref{racket-xp-previous-error}
@item @kbd{C-c # N} 
@tab @ref{racket-xp-next-error}
@item @kbd{C-c # g} 
@tab @code{racket-xp-annotate}
@item @kbd{C-c # <} 
@tab @ref{racket-xp-tail-previous-sibling}
@item @kbd{C-c # >} 
@tab @ref{racket-xp-tail-next-sibling}
@item @kbd{C-c # v} 
@tab @ref{racket-xp-tail-down}
@item @kbd{C-c # ^} 
@tab @ref{racket-xp-tail-up}
@item @kbd{C-c # r} 
@tab @code{racket-xp-rename}
@item @kbd{C-c # ?} 
@tab @code{xref-find-references}
@item @kbd{C-c # .} 
@tab @code{xref-find-definitions}
@item @kbd{C-c # p} 
@tab @ref{racket-xp-previous-use}
@item @kbd{C-c # n} 
@tab @ref{racket-xp-next-use}
@item @kbd{C-c # k} 
@tab @ref{racket-xp-previous-definition}
@item @kbd{C-c # j} 
@tab @ref{racket-xp-next-definition}
@end multitable

@node racket-xp-describe
@subsection racket-xp-describe

@kbd{C-c C-.} 

Describe something in a @code{*Racket Describe*} buffer.

The command varies based on how many @kbd{C-u} 
command prefixes you supply.

@enumerate
@item
None.

Uses the symbol at point. If no such symbol exists, you are
prompted enter the identifier, but in this case it only
considers definitions or imports at the file's module level --
not local bindings nor definitions in submodules.

@itemize
@item
If the identifier has installed Racket documentation, then a
simplified version of the HTML is presented in the buffer,
including the ``blue box'', documentation prose, and
examples.

@item
Otherwise, if the identifier is a function, then its
signature is displayed, for example "(name arg-1-name
arg-2-name)".
@end itemize

@item
@kbd{C-u} 

Always prompts you to enter a symbol, defaulting to the symbol
at point if any.

Otheriwse behaves like 0.

@item
@kbd{C-u}  @kbd{C-u} 

This is an alias for @ref{racket-search-describe}, which uses
installed documentation in a @code{racket-describe-mode} buffer
instead of an external web browser.
@end enumerate

The intent is to give a quick reminder or introduction to
something, regardless of whether it has installed documentation
-- and to do so within Emacs, without switching to a web browser.

This buffer is also displayed when you use @code{company-mode} and
press F1 or C-h in its pop up completion list.

You can quit the buffer by pressing q. Also, at the bottom of the
buffer are Emacs buttons -- which you may navigate among using
TAB, and activate using RET -- for @code{xref-find-definitions}
and @ref{racket-xp-documentation}.

@node racket-xp-documentation
@subsection racket-xp-documentation

@kbd{C-c C-d} 

View documentation in an external web browser.

The command varies based on how many @kbd{C-u} 
command prefixes you supply.

@enumerate
@item
None.

Uses the symbol at point. Tries to find documentation for an
identifer defined in the expansion of the current buffer.

If no such identifer exists, opens the Search Manuals page. In
this case, the variable @ref{racket-documentation-search-location}
determines whether the search is done locally as with `raco
doc`, or visits a URL.

@item
@kbd{C-u} 

Always prompts you to enter a symbol, defaulting to the symbol
at point if any.

Otherwise behaves like 0.

@item
@kbd{C-u}  @kbd{C-u} 

Always prompts you to enter anything, defaulting to the symbol
at point if any.

Proceeds directly to the Search Manuals page. Use this if you
would like to see documentation for all identifiers named
``define'', for example.
@end enumerate

@node racket-xp-next-definition
@subsection racket-xp-next-definition

@kbd{C-c # j} 

Move point to the next definition.

@node racket-xp-previous-definition
@subsection racket-xp-previous-definition

@kbd{C-c # k} 

Move point to the previous definition.

@node racket-xp-next-use
@subsection racket-xp-next-use

@kbd{C-c # n} 

When point is on a use, go to the next, sibling use.

@node racket-xp-previous-use
@subsection racket-xp-previous-use

@kbd{C-c # p} 

When point is on a use, go to the previous, sibling use.

@node racket-xp-next-error
@subsection racket-xp-next-error

@kbd{C-c # N} 

Go to the next error.

@node racket-xp-previous-error
@subsection racket-xp-previous-error

@kbd{C-c # P} 

Go to the previous error.

@node racket-xp-tail-up
@subsection racket-xp-tail-up

@kbd{C-c # ^} 

Go ``up'' to the expression enclosing an expression in tail position.

When point is on the opening parenthesis of an expression in tail
position, go its ``target'' -- that is, go to the enclosing
expression with the same continuation as the tail expression.

@node racket-xp-tail-down
@subsection racket-xp-tail-down

@kbd{C-c # v} 

Go ``down'' to the first tail position enclosed by the current expression.

@node racket-xp-tail-next-sibling
@subsection racket-xp-tail-next-sibling

@kbd{C-c # >} 

Go to the next tail position sharing the same enclosing expression.

@node racket-xp-tail-previous-sibling
@subsection racket-xp-tail-previous-sibling

@kbd{C-c # <} 

Go to the previous tail position sharing the same enclosing expression.

@node racket-documentation-search
@subsection racket-documentation-search

@kbd{C-c C-d} 

Search documentation.

This command is useful in several situations:

@itemize
@item
You are not using @ref{racket-xp-mode} for a @ref{racket-mode} edit
buffer, so @ref{racket-xp-documentation} is not available.

@item
There is no @ref{racket-repl-mode} buffer with a live namespace, so
@ref{racket-repl-documentation} is not available or helpful.

@item
You want to search for definitions provided by all modules --
for example, the ``define'' syntax provided by racket/base, by
typed/racket/base, and by other modules, as well definitions or
topics that merely include ``define''.
@end itemize

This command does not try to go directly to the help topic for a
definition provided by any specific module. Instead it goes to
the Racket ``Search Manuals'' page.

@node racket-search-describe
@subsection racket-search-describe

@kbd{M-x}  @code{racket-search-describe}

Search installed documentation; view using @code{racket-describe-mode}.

Always prompts you to enter a symbol, defaulting to the symbol at
point if any.

@itemize
@item
If just one module exports the name, you go directly to a
Racket Describe buffer with its documentation.

@item
If multiple modules export the name, you go first to a
``disambiguation'' buffer similar to the Racket ``Search
Manuals'' web page. You may press RET on any item to get a
Racket Describe buffer for that module's version of the thing.
@end itemize

@node Run
@section Run

@menu
* racket-repl-mode::
* racket-run::
* racket-run-and-switch-to-repl::
* racket-run-module-at-point::
* racket-repl::
* racket-repl-describe::
* racket-repl-documentation::
* racket-racket::
* racket-profile::
* racket-profile-mode::
* racket-logger::
* racket-logger-mode::
* racket-debug-mode::
* racket-repl-clear::
* racket-repl-clear-leaving-last-prompt::
@end menu

@node racket-repl-mode
@subsection racket-repl-mode

@kbd{M-x}  @code{racket-repl-mode}

Major mode for Racket REPL.

You may use @code{xref-find-definitions} @kbd{M-.}  and
@code{xref-pop-marker-stack} @kbd{M-,} :
@ref{racket-repl-mode} adds a backend to the variable
@code{xref-backend-functions}. This backend uses information about
identifier bindings and modules from the REPL's namespace.

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{@}} 
@tab @ref{racket-insert-closing}
@item @kbd{]} 
@tab @ref{racket-insert-closing}
@item @kbd{)} 
@tab @ref{racket-insert-closing}
@item @kbd{C-c C-\} 
@tab @code{racket-repl-exit}
@item @kbd{C-c C-c} 
@tab @code{racket-repl-break}
@item @kbd{C-c C-l} 
@tab @ref{racket-logger}
@item @kbd{C-c C-z} 
@tab @code{racket-repl-switch-to-edit}
@item @kbd{C-c C-.} 
@tab @ref{racket-repl-describe}
@item @kbd{C-c C-d} 
@tab @ref{racket-repl-documentation}
@item @kbd{C-c C-e r} 
@tab @ref{racket-expand-region}
@item @kbd{C-c C-e e} 
@tab @ref{racket-expand-last-sexp}
@item @kbd{C-c C-e x} 
@tab @ref{racket-expand-definition}
@item @kbd{C-c C-e f} 
@tab @ref{racket-expand-file}
@item @kbd{C-w} 
@tab @code{comint-kill-region}
@item @kbd{C-a} 
@tab @code{comint-bol}
@item @kbd{C-M-y} 
@tab @ref{racket-insert-lambda}
@item @kbd{C-M-q} 
@tab @code{prog-indent-sexp}
@item @kbd{C-M-u} 
@tab @ref{racket-backward-up-list}
@item @kbd{TAB} 
@tab @code{indent-for-tab-command}
@item @kbd{C-j} 
@tab @code{newline-and-indent}
@item @kbd{RET} 
@tab @code{racket-repl-submit}
@end multitable



In addition to any hooks its parent mode @code{comint-mode} might have run,
this mode runs the hook @code{racket-repl-mode-hook}, as the final step
during initialization.

@node racket-run
@subsection racket-run

@kbd{M-x}  @code{racket-run}

Save the buffer in REPL and run your program.

As well as evaluating the outermost, file module, automatically
runs the submodules specified by the customization variable
@ref{racket-submodules-to-run}.

See also @ref{racket-run-module-at-point}, which runs just the
specific module at point.

With @kbd{C-u}  uses errortrace for improved stack traces.
Otherwise follows the @ref{racket-error-context} setting.

With @kbd{C-u}  @kbd{C-u}  instruments
code for step debugging. See @ref{racket-debug-mode} and the variable
@ref{racket-debuggable-files}.

Each run occurs within a Racket custodian. Any prior run's
custodian is shut down, releasing resources like threads and
ports. Each run's evaluation environment is reset to the contents
of the source file. In other words, like Dr Racket, this provides
the benefit that your source file is the ``single source of
truth''. At the same time, the run gives you a REPL inside the
namespace of the module, giving you the ability to explore it
interactively. Any explorations are temporary, unless you also
make them to your source file, they will be lost on the next run.

See also @ref{racket-run-and-switch-to-repl}, which is even more like
Dr Racket's Run command because it selects the REPL window after
running.

In the @ref{racket-repl-mode} buffer, output that describes a file
and position is automatically ``linkified''. Examples of such
text include:

@itemize
@item
Racket error messages.
@item
rackunit test failure location messages.
@item
print representation of path objects.
@end itemize

To visit these locations, move point there and press RET or mouse
click. Or, use the standard @code{next-error} and @code{previous-error}
commands.

@node racket-run-and-switch-to-repl
@subsection racket-run-and-switch-to-repl

@kbd{<f5>} 

This is @ref{racket-run} followed by selecting the REPL buffer window.

This is similar to how Dr Racket behaves.

To make it even more similar, you may add @ref{racket-repl-clear} to
the variable @ref{racket-before-run-hook}.

@node racket-run-module-at-point
@subsection racket-run-module-at-point

@kbd{C-c C-k}  or @kbd{C-c C-c} 

Save the buffer and run the module at point.

Like @ref{racket-run} but runs the innermost module around point,
which is determined textually by looking for ``module'',
``module*'', or ``module+'' forms nested to any depth, else
simply the outermost, file module.

@node racket-repl
@subsection racket-repl

@kbd{C-c C-z} 

Show a Racket REPL buffer in some window.

@strong{IMPORTANT}

The main, intended use of Racket Mode's REPL is that you
@code{find-file} some specific .rkt file, then @ref{racket-run} it. The
REPL will then match that file.

If the REPL isn't running, and you want to start it for no file
in particular? Then you could use this command. But the resulting
REPL will have a minimal ``#lang racket/base'' namespace. You
could enter "(require racket)" if you want the equivalent of
``#lang racket''. You could also "(require racket/enter)" if
you want things like ``enter!''. But in some sense you'd be
``using it wrong''. If you really don't want to use Racket Mode's
REPL as intended, then you might as well use a plain Emacs shell
buffer to run command-line Racket.

@node racket-repl-describe
@subsection racket-repl-describe

@kbd{C-c C-.} 

Describe the identifier at point in a @code{*Racket Describe*} buffer.

The command varies based on how many @kbd{C-u} 
command prefixes you supply.

@enumerate
@item
None.

Uses the symbol at point. If no such symbol exists, you are
prompted enter the identifier, but in this case it only
considers definitions or imports at the file's module level --
not local bindings nor definitions in submodules.

@itemize
@item
If the identifier has installed Racket documentation, then a
simplified version of the HTML is presented in the buffer,
including the ``blue box'', documentation prose, and
examples.

@item
Otherwise, if the identifier is a function, then its
signature is displayed, for example "(name arg-1-name
arg-2-name)".
@end itemize

@item
@kbd{C-u} 

Always prompts you to enter a symbol, defaulting to the symbol
at point if any.

Otheriwse behaves like 0.

@item
@kbd{C-u}  @kbd{C-u} 

This is an alias for @ref{racket-search-describe}, which uses
installed documentation in a @code{racket-describe-mode} buffer
instead of an external web browser.
@end enumerate

The intent is to give a quick reminder or introduction to
something, regardless of whether it has installed documentation
-- and to do so within Emacs, without switching to a web browser.

You can quit the buffer by pressing q. Also, at the bottom of the
buffer are Emacs buttons -- which you may navigate among using
TAB, and activate using RET -- for @code{xref-find-definitions}
and @ref{racket-repl-documentation}.

@node racket-repl-documentation
@subsection racket-repl-documentation

@kbd{C-c C-d} 

View documentation in an external web browser.

The command varies based on how many @kbd{C-u}  command prefixes you supply.

@enumerate
@item
None.

Uses the symbol at point. Tries to find documentation for an
identifer defined in the current namespace.

If no such identifer exists, opens the Search Manuals page. In
this case, the variable @ref{racket-documentation-search-location}
determines whether the search is done locally as with `raco
doc`, or visits a URL.

@item
@kbd{C-u} 

Prompts you to enter a symbol, defaulting to the symbol at
point if any.

Otherwise behaves like 1.

@item
@kbd{C-u}  @kbd{C-u} 

Prompts you to enter anything, defaulting to the symbol at
point if any.

Proceeds directly to the Search Manuals page. Use this if you
would like to see documentation for all identifiers named
``define'', for example.
@end enumerate

@node racket-racket
@subsection racket-racket

@kbd{<C-M-f5>} 

Do ``racket <file>'' in a shell buffer.

@node racket-profile
@subsection racket-profile

@kbd{C-c C-o} 

Like @ref{racket-run-module-at-point} but with profiling.

Results are presented in a @ref{racket-profile-mode} buffer, which
also lets you quickly view the source code.

You may evaluate expressions in the REPL. They are also profiled.
Use @code{racket-profile-refresh} to see the updated results. In
other words a possible workflow is: @ref{racket-profile} a .rkt file,
call one its functions in the REPL, and refresh the profile
results.

Caveat: Only source files are instrumented. You may need to
delete compiled/*.zo files.

@node racket-profile-mode
@subsection racket-profile-mode

@kbd{M-x}  @code{racket-profile-mode}

Major mode for results of @ref{racket-profile}.

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{,} 
@tab @code{racket-profile-sort}
@item @kbd{f} 
@tab @code{racket-profile-show-non-project}
@item @kbd{z} 
@tab @code{racket-profile-show-zero}
@item @kbd{p} 
@tab @code{racket-profile-prev}
@item @kbd{n} 
@tab @code{racket-profile-next}
@item @kbd{g} 
@tab @code{racket-profile-refresh}
@item @kbd{q} 
@tab @code{quit-window}
@end multitable




In addition to any hooks its parent mode @code{special-mode} might have run,
this mode runs the hook @code{racket-profile-mode-hook}, as the final step
during initialization.

@node racket-logger
@subsection racket-logger

@kbd{C-c C-l} 

Create the @ref{racket-logger-mode} buffer.

@node racket-logger-mode
@subsection racket-logger-mode

@kbd{M-x}  @code{racket-logger-mode}

Major mode for Racket logger output.


The customization variable @ref{racket-logger-config} determines the
levels for topics. During a session you may change topic levels
using @code{racket-logger-topic-level}.

For more information see:
  @uref{https://docs.racket-lang.org/reference/logging.html}

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{g} 
@tab @code{racket-logger-clear}
@item @kbd{p} 
@tab @code{racket-logger-previous-item}
@item @kbd{n} 
@tab @code{racket-logger-next-item}
@item @kbd{w} 
@tab @code{toggle-truncate-lines}
@item @kbd{l} 
@tab @code{racket-logger-topic-level}
@end multitable




In addition to any hooks its parent mode @code{special-mode} might have run,
this mode runs the hook @code{racket-logger-mode-hook}, as the final step
during initialization.

@node racket-debug-mode
@subsection racket-debug-mode

@kbd{M-x}  @code{racket-debug-mode}

Minor mode for debug breaks.

This feature is @strong{@strong{EXPERIMENTAL}}!!! It is likely to have
significant limitations and bugs. You are welcome to open an
issue to provide feedback. Please understand that this feature
might never be improved -- it might even be removed someday if it
turns out to have too little value and/or too much cost.

How to debug:

@enumerate
@item
``Instrument'' code for step debugging. You can instrument
entire files, and also individual functions.

a. Entire Files

Use two @kbd{C-u}  command prefixes for either
@ref{racket-run} or @ref{racket-run-module-at-point}.

The file will be instrumented for step debugging before it
is run. Also instrumented are files determined by the
variable @ref{racket-debuggable-files}.

The run will break at the first breakable position.

Tip: After you run to completion and return to a normal
REPL prompt, the code remains instrumented. You may enter
expressions that evaluate instrumented code and it will
break so you can step debug again.

b. Function Definitions

Move point inside a function definition form and use
@kbd{C-u}  @kbd{C-M-x}  to
``instrument'' the function for step debugging. Then in the
REPL, enter an expression that causes the instrumented
function to be run, directly or indirectly.

You can instrument any number of functions.

You can even instrument while stopped at a break. For
example, to instrument a function you are about to call, so
you can ``step into'' it:

@itemize
@item
@kbd{M-x}  @code{racket-xp-visit-definition} to visit the definition.
@item
@kbd{C-u}  @kbd{C-M-x}  to instrument the definition.
@item
@kbd{M-x}  @code{racket-unvisit} to return.
@item
Continue stepping.
@end itemize
Limitation: Instrumenting a function required from another
module won't redefine that function. Instead, it attempts
to define an instrumented function of the same name, in the
module the REPL is inside. The define will fail if it needs
definitions visible only in that other module. In that case
you'll probably need to use entire-file instrumentation as
described above.

@item
When a break occurs, the @ref{racket-repl-mode} prompt changes. In
this debug REPL, local variables are available for you to use
and even to @code{set!}.

Also, in the @ref{racket-mode} buffer where the break is located,
@ref{racket-debug-mode} is enabled. This minor mode makes the
buffer read-only, provides visual feedback -- about the break
position, local variable values, and result values -- and
provides shortcut keys:
@end enumerate

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{?} 
@tab @code{racket-debug-help}
@item @kbd{h} 
@tab @code{racket-debug-run-to-here}
@item @kbd{p} 
@tab @code{racket-debug-prev-breakable}
@item @kbd{n} 
@tab @code{racket-debug-next-breakable}
@item @kbd{c} 
@tab @code{racket-debug-continue}
@item @kbd{u} 
@tab @code{racket-debug-step-out}
@item @kbd{o} 
@tab @code{racket-debug-step-over}
@item @kbd{SPC} 
@tab @code{racket-debug-step}
@end multitable

@node racket-repl-clear
@subsection racket-repl-clear

Delete all text in the REPL.

A suitable value for the hook @ref{racket-before-run-hook} if you
want the REPL buffer to be cleared before each run, much like
with Dr Racket. To do so you can use @code{customize}, or, add to your
Emacs init file something like:

(add-hook `racket-before-run-hook #'racket-repl-clear)

See also the command @ref{racket-repl-clear-leaving-last-prompt}.

@node racket-repl-clear-leaving-last-prompt
@subsection racket-repl-clear-leaving-last-prompt

@kbd{M-x}  @code{racket-repl-clear-leaving-last-prompt}

Delete all text in the REPL, except for the last prompt.

@node Test
@section Test

@menu
* racket-test::
* racket-raco-test::
@end menu

@node racket-test
@subsection racket-test

@kbd{<C-f5>}  or @kbd{C-c C-t} 

Run the ``test'' submodule.

Put your tests in a ``test'' submodule. For example:

@example
(module+ test
  (require rackunit)
  (check-true #t))
@end example

Any rackunit test failure messages show the location. You may use
@code{next-error} to jump to the location of each failing test.

With @kbd{C-u}  also runs the tests with coverage
instrumentation and highlights uncovered code using
@code{font-lock-warning-face}.

See also:
@itemize
@item
@ref{racket-fold-all-tests}
@item
@ref{racket-unfold-all-tests}
@end itemize

@node racket-raco-test
@subsection racket-raco-test

@kbd{M-x}  @code{racket-raco-test}

Do ``raco test -x <file>'' in a shell buffer to run the ``test'' submodule.

@node Eval
@section Eval

@menu
* racket-send-region::
* racket-send-definition::
* racket-send-last-sexp::
@end menu

@node racket-send-region
@subsection racket-send-region

@kbd{C-c C-r} 

Send the current region (if any) to the Racket REPL.

@node racket-send-definition
@subsection racket-send-definition

@kbd{C-M-x} 

Send the current definition to the Racket REPL.

@node racket-send-last-sexp
@subsection racket-send-last-sexp

@kbd{C-x C-e} 

Send the previous sexp to the Racket REPL.

When the previous sexp is a sexp comment the sexp itself is sent,
without the #; prefix.

@node Collections
@section Collections

@menu
* racket-open-require-path::
* racket-find-collection::
@end menu

@node racket-open-require-path
@subsection racket-open-require-path

@kbd{C-c C-x C-f} 

Like Dr Racket's Open Require Path.

Type (or delete) characters that are part of a module path name.
``Fuzzy'' matches appear. For example try typing ``t/t/r''.

Choices are displayed in a vertical list. The current choice is
at the top, marked with ``->''.

@itemize
@item
C-n and C-p move among the choices.
@item
RET on a directory adds its contents to the choices.
@item
RET on a file exits doing @code{find-file}.
@item
C-g aborts.
@end itemize

@node racket-find-collection
@subsection racket-find-collection

@kbd{M-x}  @code{racket-find-collection}

Given a collection name, try to find its directory and files.

Takes a collection name from point.

With @kbd{C-u}  prompts you.

If only one directory is found, @code{ido-find-file-in-dir} lets you
pick a file there.

If more than one directory is found, @code{ido-completing-read} lets
you pick one, then @code{ido-find-file-in-dir} lets you pick a file
there.

Note: This requires the @code{raco-find-collection} package to be
installed. To install it, in @code{shell} enter:

raco pkg install raco-find-collection

Tip: This works best with @code{ido-enable-flex-matching} set to t.
Also handy is the @code{flx-ido} package from MELPA.

See also: @ref{racket-open-require-path}.

@node Macro expand
@section Macro expand

@menu
* racket-stepper-mode::
* racket-expand-file::
* racket-expand-region::
* racket-expand-definition::
* racket-expand-last-sexp::
@end menu

@node racket-stepper-mode
@subsection racket-stepper-mode

@kbd{M-x}  @code{racket-stepper-mode}

Major mode for Racket stepper output.


Used by the commands @ref{racket-expand-file},
@ref{racket-expand-definition}, @ref{racket-expand-region}, and
@ref{racket-expand-last-sexp}.

@multitable {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
@item Key
@tab Binding
@item @kbd{k} 
@tab @code{racket-stepper-previous-item}
@item @kbd{p} 
@tab @code{racket-stepper-previous-item}
@item @kbd{j} 
@tab @code{racket-stepper-next-item}
@item @kbd{n} 
@tab @code{racket-stepper-next-item}
@item @kbd{RET} 
@tab @code{racket-stepper-step}
@end multitable




In addition to any hooks its parent mode @code{special-mode} might have run,
this mode runs the hook @code{racket-stepper-mode-hook}, as the final step
during initialization.

@node racket-expand-file
@subsection racket-expand-file

@kbd{C-c C-e f} 

Expand the @ref{racket-mode} buffer's file in @ref{racket-stepper-mode}.

Uses the @code{macro-debugger} package to do the expansion.

You do need to @ref{racket-run} the file first; the namespace
active in the REPL is not used.

If the file is non-trivial and/or is not compiled to a .zo
bytecode file, then it might take many seconds before the
original form is displayed and you can start stepping.

With @kbd{C-u}  also expands syntax from racket/base
-- which can result in very many expansion steps.

@node racket-expand-region
@subsection racket-expand-region

@kbd{C-c C-e r} 

Expand the active region using @ref{racket-stepper-mode}.

Uses Racket's @code{expand-once} in the namespace from the most recent
@ref{racket-run}.

@node racket-expand-definition
@subsection racket-expand-definition

@kbd{C-c C-e x} 

Expand the definition around point using @ref{racket-stepper-mode}.

Uses Racket's @code{expand-once} in the namespace from the most recent
@ref{racket-run}.

@node racket-expand-last-sexp
@subsection racket-expand-last-sexp

@kbd{C-c C-e e} 

Expand the sexp before point using @ref{racket-stepper-mode}.

Uses Racket's @code{expand-once} in the namespace from the most recent
@ref{racket-run}.

@node Other
@section Other

@menu
* racket-mode-start-faster::
* racket-mode-start-slower::
@end menu

@node racket-mode-start-faster
@subsection racket-mode-start-faster

@kbd{M-x}  @code{racket-mode-start-faster}

Compile Racket Mode's .rkt files for faster startup.

Racket Mode is implemented as an Emacs Lisp ``front end'' that
talks to a Racket process ``back end''. Because Racket Mode is
delivered as an Emacs package instead of a Racket package,
installing it does not do the @code{raco setup} that is normally done
for Racket packages.

This command will do a @code{raco make} of Racket Mode's .rkt files,
creating bytecode files in @code{compiled/} subdirectories. As a
result, when a command must start the Racket process, it will
start somewhat faster.

On many computers, the resulting speed up is negligible, and
might not be worth the complication.

If you run this command, ever, you will need to run it again
after:

@itemize
@item
Installing an updated version of Racket Mode. Otherwise, you
might lose some of the speed-up.

@item
Installing a new version of Racket and/or changing the value of
the variable @ref{racket-program}. Otherwise, you might get an
error message due to the bytecode being different versions.
@end itemize

To revert to compiling on startup, use
@ref{racket-mode-start-slower}. 

@node racket-mode-start-slower
@subsection racket-mode-start-slower

@kbd{M-x}  @code{racket-mode-start-slower}

Delete the ``compiled'' directories made by @ref{racket-mode-start-faster}.

@node Showing information
@section Showing information

@menu
* racket-show-pseudo-tooltip::
* racket-show-echo-area::
* racket-show-header-line::
* racket-show-pos-tip::
@end menu

@node racket-show-pseudo-tooltip
@subsection racket-show-pseudo-tooltip

Show using an overlay that resembles a tooltip.

This is nicer than @ref{racket-show-pos-tip} because it:

@itemize
@item
Doesn't flicker while navigating.
@item
Doesn't disappear after a timeout.
@item
Performs well when @code{x-gtk-use-system-tooltips} is nil.
@end itemize

On the other hand, this does not look as nice when displaying
text that spans multiple lines. In that case, we simply
left-justify everything and do not draw any border.

@node racket-show-echo-area
@subsection racket-show-echo-area

Show things in the echo area.

A value for the variable @ref{racket-show-functions}.

@node racket-show-header-line
@subsection racket-show-header-line

Show things using a buffer header line.

A value for the variable @ref{racket-show-functions}.

When there is nothing to show, keep a blank header-line. That
way, the buffer below doesn't ``jump up and down'' by a line as
messages appear and disappear. Only when V is nil do we remove
the header line.

@node racket-show-pos-tip
@subsection racket-show-pos-tip

Show things using @code{pos-tip-show} if available.

A value for the variable @ref{racket-show-functions}.

@node Associating edit buffers with REPL buffers
@section Associating edit buffers with REPL buffers

@menu
* racket-repl-buffer-name-shared::
* racket-repl-buffer-name-unique::
* racket-repl-buffer-name-project::
* racket-project-root::
@end menu

@node racket-repl-buffer-name-shared
@subsection racket-repl-buffer-name-shared

@kbd{M-x}  @code{racket-repl-buffer-name-shared}

All @ref{racket-mode} edit buffers share one @ref{racket-repl-mode} buffer.

A value for the variable @ref{racket-repl-buffer-name-function}.

@node racket-repl-buffer-name-unique
@subsection racket-repl-buffer-name-unique

@kbd{M-x}  @code{racket-repl-buffer-name-unique}

Each @ref{racket-mode} edit buffer gets its own @ref{racket-repl-mode} buffer.

A value for the variable @ref{racket-repl-buffer-name-function}.

@node racket-repl-buffer-name-project
@subsection racket-repl-buffer-name-project

@kbd{M-x}  @code{racket-repl-buffer-name-project}

All @ref{racket-mode} buffers in a project share a @ref{racket-repl-mode} buffer.

A value for the variable @ref{racket-repl-buffer-name-function}.

The ``project'' is determined by @ref{racket-project-root}.

@node racket-project-root
@subsection racket-project-root

Given an absolute pathname for FILE, return its project root directory.

The ``project'' is determined by trying, in order:

@itemize
@item
@code{projectile-project-root}
@item
@code{vc-root-dir}
@item
@code{project-current}
@item
@code{file-name-directory}
@end itemize

@node Browsing file URLs with anchors
@section Browsing file URLs with anchors

@menu
* racket-browse-url-using-temporary-file::
@end menu

@node racket-browse-url-using-temporary-file
@subsection racket-browse-url-using-temporary-file

Browse a URL via a temporary HTML file using a meta redirect.

A suitable value for the variable @ref{racket-browse-url-function}.

Racket documentation URLs depend on anchors -- the portion of the
URL after the # character -- to jump to a location within a page.
Unfortunately on some operating systems and/or versions of Emacs,
the default handling for browsing file URLs ignores anchors. This
function attempts to avoid the problem by using a temporary HTML
file with a meta redirect as a ``trampoline''.

Although the intent is to provide a default that ``just works'',
you do not need to use this. You can customize the variable
@ref{racket-browse-url-function} instead to be @code{browse-url}, or
@code{browse-url-browser-function} in case have have customized that,
or indeed whatever you want.

@node Variables
@chapter Variables

@menu
* General variables::
* REPL variables::
* Other variables::
* Experimental debugger variables::
* Showing information: Showing informationx. 
@end menu

@node General variables
@section General variables

@menu
* racket-program::
* racket-command-timeout::
* racket-memory-limit::
* racket-error-context::
* racket-user-command-line-arguments::
* racket-path-from-emacs-to-racket-function::
* racket-path-from-racket-to-emacs-function::
* racket-browse-url-function::
* racket-xp-after-change-refresh-delay::
* racket-xp-highlight-unused-regexp::
* racket-documentation-search-location::
@end menu

@node racket-program
@subsection racket-program

Pathname of the racket executable.

@node racket-command-timeout
@subsection racket-command-timeout

How many seconds to wait for command server responses.

Note: This is mostly obsolete, fortunately, because it applies
only to commands that must block the Emacs UI until they get a
response. Instead most Racket Mode commands these days receive
their response asychronously.

@node racket-memory-limit
@subsection racket-memory-limit

Terminate the Racket process if memory use exceeds this value in MB.

Changes to this value take effect upon the next @ref{racket-run}. A value
of 0 means no limit.

Caveat: This uses Racket's @code{custodian-limit-memory}, which does
not enforce the limit exactly. Instead, the program will be
terminated upon the first garbage collection where memory exceeds
the limit (maybe by a significant amount).

@node racket-error-context
@subsection racket-error-context

The amount of context for error messages.

Each increasing level supplies better context (``stack trace'')
for error messages, but causing your program to run more slowly.

@itemize
@item
low corresponds to compile-enforce-module-constants #t and
compile-context-preservation-enabled #f.

@item
medium corresponds to compile-enforce-module-constants #f and
compile-context-preservation-enabled #t, which disables some
optimizations like inlining.

@item
high corresponds to medium plus the use of errortrace, which
extensively instruments your code and therefore might cause
it to run significantly slower.
@end itemize

Tip: Regardless of this setting, you can enable high errortrace
for a specific @ref{racket-run} or @ref{racket-run-module-at-point} by
using @kbd{C-u} . This lets you normally run with a
lower, faster setting, and re-run when desired to get a
more-helpful error message.

@node racket-user-command-line-arguments
@subsection racket-user-command-line-arguments

List of command-line arguments to supply to your Racket program.

Accessible in your Racket program in the usual way --- the
parameter @code{current-command-line-arguments} and friends.

This is an Emacs buffer-local variable --- convenient to set as a
file local variable. For example at the end of your .rkt file:

@lisp
;; Local Variables:
;; racket-user-command-line-arguments: ("-f" "bar")
;; End:
@end lisp

Set this way, the value must be an @strong{unquoted} list of strings.
For example:

@lisp
("-f" "bar")
@end lisp

The following values will @emph{not} work:

@lisp
'("-f" "bar")
(list "-f" "bar")
@end lisp

@node racket-path-from-emacs-to-racket-function
@subsection racket-path-from-emacs-to-racket-function

A function to transform Emacs Lisp pathnames given to the Racket back end.

If you run Emacs on Windows Subsystem for Linux, and want to run
Racket programs using Windows Racket.exe rather than Linux
racket, you can set this to @code{racket-wsl-to-windows}. In that case
you probably also want to customize the ``reverse'':
@ref{racket-path-from-racket-to-emacs-function}.

@node racket-path-from-racket-to-emacs-function
@subsection racket-path-from-racket-to-emacs-function

A function to transform Racket back end pathnames given to Emacs Lisp.

The default on Windows replaces back with forward slashes. The
default elsewhere is @code{identity}.

If you run Emacs on Windows Subsystem for Linux, and want to run
Racket programs using Windows Racket.exe rather than Linux
racket, you can set this to @code{racket-windows-to-wsl}. In that case
you probably also want to customize the ``reverse'':
@ref{racket-path-from-emacs-to-racket-function}.

@node racket-browse-url-function
@subsection racket-browse-url-function

Function to call to browse a URL.

@node racket-xp-after-change-refresh-delay
@subsection racket-xp-after-change-refresh-delay

Seconds to wait before refreshing @ref{racket-xp-mode} annotations.

Set to nil to disable automatic refresh and manually use @code{racket-xp-annotate}.

@node racket-xp-highlight-unused-regexp
@subsection racket-xp-highlight-unused-regexp

Only give @ref{racket-xp-unused-face} to unused bindings that match this regexp.

The default is to highlight identifiers that do not start with
an underline, which is a common convention.

@node racket-documentation-search-location
@subsection racket-documentation-search-location

The location of the Racket ``Search Manuals'' web page.
Where @ref{racket-documentation-search}, @ref{racket-xp-documentation}
and @ref{racket-repl-documentation} should look for the search page.

@itemize
@item
If the value of this variable is `local, open the search page
from the local documentation, as with ``raco doc''.

@item
Otherwise, the value is a string recognizable by @code{format}, with
``%s'' at the point at which to insert the user's search text.
the help desk. Apart from ``%s'', the string should be a
properly encoded URL.
@end itemize

@node REPL variables
@section REPL variables

@menu
* racket-repl-buffer-name-function::
* racket-submodules-to-run::
* racket-repl-history-directory::
* racket-history-filter-regexp::
* racket-images-inline::
* racket-imagemagick-props::
* racket-images-keep-last::
* racket-images-system-viewer::
* racket-pretty-print::
@end menu

@node racket-repl-buffer-name-function
@subsection racket-repl-buffer-name-function

How to associate @ref{racket-mode} edit buffers with @ref{racket-repl-mode} buffers.

The default is nil, which is equivalent to supplying
@ref{racket-repl-buffer-name-shared}: One REPL buffer is shared.

Other predefined choices include @ref{racket-repl-buffer-name-unique}
and @ref{racket-repl-buffer-name-project}.

This is used when a @ref{racket-mode} buffer is created. Changing
this to a new value only affects @ref{racket-mode} buffers created
later.

Any such function takes no arguments, should look at
@code{buffer-file-name} if necessary, and either @code{setq-default} or
@code{setq-local} the variable @code{racket-repl-buffer-name} to a desired
@ref{racket-repl-mode} buffer name. As a result, @ref{racket-run}
commands will use a buffer of that name, creating it if
necessary.

@node racket-submodules-to-run
@subsection racket-submodules-to-run

Extra submodules to run.

This is a list of submodules. Each submodule is described as a
list, to support submodules nested to any depth.

This is used by commands that emulate the DrRacket Run command:



@itemize
@item
@ref{racket-run}
@item
@ref{racket-run-and-switch-to-repl} @kbd{<f5>} 
@end itemize

It is NOT used by commands that run one specific module, such as:

@itemize
@item
@ref{racket-run-module-at-point} @kbd{C-c C-k}  or @kbd{C-c C-c} 
@item
@ref{racket-test} @kbd{<C-f5>}  or @kbd{C-c C-t} 
@item
@ref{racket-profile}
@end itemize

@node racket-repl-history-directory
@subsection racket-repl-history-directory

Directory for @ref{racket-repl-mode} history files.

@node racket-history-filter-regexp
@subsection racket-history-filter-regexp

Input matching this regexp are NOT saved on the history list.
Default value is a regexp to ignore input that is all whitespace.

@node racket-images-inline
@subsection racket-images-inline

Whether to display inline images in the REPL.

@node racket-imagemagick-props
@subsection racket-imagemagick-props

Use ImageMagick with these properties for REPL images.

When this property list is not empty -- and the variable
@ref{racket-images-inline} is true, and Emacs is built with with
ImageMagick support -- then @code{create-image} is called with
``imagemagick'' as the type and with this property list.

For example, to scale images whose width is larger than 500
pixels, supply (:max-width 500).

@node racket-images-keep-last
@subsection racket-images-keep-last

How many images to keep in the image cache.

@node racket-images-system-viewer
@subsection racket-images-system-viewer

The image viewer program to use for @code{racket-view-image}.

@node racket-pretty-print
@subsection racket-pretty-print

Use pretty-print instead of print in REPL?

@node Other variables
@section Other variables

@menu
* racket-indent-curly-as-sequence::
* racket-indent-sequence-depth::
* racket-pretty-lambda::
* racket-smart-open-bracket-enable::
* racket-logger-config::
* racket-before-run-hook::
* racket-after-run-hook::
@end menu

@node racket-indent-curly-as-sequence
@subsection racket-indent-curly-as-sequence

Indent @code{@{@}} with items aligned with the head item?

This is indirectly disabled if @ref{racket-indent-sequence-depth} is 0.
This is safe to set as a file-local variable.

@node racket-indent-sequence-depth
@subsection racket-indent-sequence-depth

To what depth should @ref{racket-indent-line} search.

This affects the indentation of forms like '() `() #() --
and @{@} if @ref{racket-indent-curly-as-sequence} is t --- but not
#'() #`() ,() ,@@(). A zero value disables, giving the normal
indent behavior of DrRacket or Emacs @code{lisp-mode} derived modes
like @code{scheme-mode}. Setting this to a high value can make
indentation noticeably slower. This is safe to set as a
file-local variable.

@node racket-pretty-lambda
@subsection racket-pretty-lambda

Display lambda keywords using λ. This is DEPRECATED.

Instead use @code{prettify-symbols-mode} in newer verisons of Emacs,
or, use @ref{racket-insert-lambda} to insert actual λ characters.

@node racket-smart-open-bracket-enable
@subsection racket-smart-open-bracket-enable

This variable is obsolete and has no effect.

Instead of using this variable, you may bind the @code{[} key to the
@code{racket-smart-open-bracket} command in the @code{racket-mode-map}
and/or @code{racket-repl-mode-map} keymaps.

@node racket-logger-config
@subsection racket-logger-config

Configuration of @ref{racket-logger-mode} topics and levels.

The topic `* respresents the default level used for topics not
assigned a level. Otherwise, the topic symbols are the same as
used by Racket's @code{define-logger}.

The levels are those used by Racket's logging system: `debug,
`info, `warning, `error, `fatal.

For more information see:
  @uref{https://docs.racket-lang.org/reference/logging.html}

The default value sets some known ``noisy'' topics to be one
level quieter. That way you can set the `* topic to a level like
`debug and not get overhwelmed by these noisy topics.

@node racket-before-run-hook
@subsection racket-before-run-hook

Normal hook done before various Racket Mode run commands.

When hook functions are called, @code{current-buffer} is that of the
@ref{racket-mode} buffer when the run command was issued. If a hook
function instead needs the @ref{racket-repl-mode} buffer, it should
get that from the variable @code{racket-repl-buffer-name}.

@node racket-after-run-hook
@subsection racket-after-run-hook

Normal hook done after various Racket Mode run commands.

Here ``after'' means that the run has completed and the REPL is
waiting at another prompt.

When hook functions are called, @code{current-buffer} is that of the
@ref{racket-mode} buffer when the run command was issued. If a hook
function instead needs the @ref{racket-repl-mode} buffer, it should
get that from the variable @code{racket-repl-buffer-name}.

@node Experimental debugger variables
@section Experimental debugger variables

@menu
* racket-debuggable-files::
@end menu

@node racket-debuggable-files
@subsection racket-debuggable-files

Used to tell @ref{racket-run} what files may be instrumented for debugging.
Must be a list of strings that are pathnames, such as from
@code{racket--buffer-file-name}, -or-, a function that returns such a
list given the pathname of the file being run. If any path
strings are relative, they are made absolute using
@code{expand-file-name} with the directory of the file being run. The
symbol `run-file may be supplied in the list; it will be replaced
with the pathname of the file being run. Safe to set as a
file-local variable.

@node Showing informationx
@section Showing information

@menu
* racket-show-functions::
@end menu

@node racket-show-functions
@subsection racket-show-functions

A special hook variable to customize @code{racket-show}.

Example functions include:

@itemize
@item
@ref{racket-show-pseudo-tooltip}
@item
@ref{racket-show-echo-area}
@item
@ref{racket-show-pos-tip}
@item
@ref{racket-show-header-line}
@end itemize

Each function should accept two arguments: VAL and POS.

VAL is:

@itemize
@item
Non-blank string: Display the string somehow.

@item
Blank string: Hide any previously displayed string.

@item
nil: Hide any persistent UI that might have been created to
show strings, such as by @ref{racket-show-header-line}.
@end itemize

POS is the buffer position for which to show the message. It may
be nil only when VAL is nil or a blank string. When the buffer
content is a span, POS should be the end of the span. That way,
for example, a function that shows a tooltip can position it not
to hide the interesting span in the buffer.

@node Faces
@chapter Faces

@menu
* All::
@end menu

@node All
@section All

@menu
* racket-keyword-argument-face::
* racket-selfeval-face::
* racket-here-string-face::
* racket-xp-def-face::
* racket-xp-use-face::
* racket-xp-unused-face::
* racket-xp-tail-target-face::
* racket-xp-tail-position-face::
* racket-logger-config-face::
* racket-logger-topic-face::
* racket-logger-fatal-face::
* racket-logger-error-face::
* racket-logger-warning-face::
* racket-logger-info-face::
* racket-logger-debug-face::
@end menu

@node racket-keyword-argument-face
@subsection racket-keyword-argument-face

Face for @code{#:keyword} arguments.

@node racket-selfeval-face
@subsection racket-selfeval-face

Face for self-evaluating expressions like numbers, symbols, strings.

@node racket-here-string-face
@subsection racket-here-string-face

Face for here strings.

@node racket-xp-def-face
@subsection racket-xp-def-face

Face @ref{racket-xp-mode} uses to highlight definitions.

@node racket-xp-use-face
@subsection racket-xp-use-face

Face @ref{racket-xp-mode} uses to highlight uses.

@node racket-xp-unused-face
@subsection racket-xp-unused-face

Face @ref{racket-xp-mode} uses to highlight unused requires or definitions.

@node racket-xp-tail-target-face
@subsection racket-xp-tail-target-face

Face @ref{racket-xp-mode} uses to highlight targets of a tail position.

@node racket-xp-tail-position-face
@subsection racket-xp-tail-position-face

Face @ref{racket-xp-mode} uses to highlight expressions in a tail position.

@node racket-logger-config-face
@subsection racket-logger-config-face

Face for @ref{racket-logger-mode} configuration.

@node racket-logger-topic-face
@subsection racket-logger-topic-face

Face for @ref{racket-logger-mode} topics.

@node racket-logger-fatal-face
@subsection racket-logger-fatal-face

Face for @ref{racket-logger-mode} fatal level.

@node racket-logger-error-face
@subsection racket-logger-error-face

Face for @ref{racket-logger-mode} error level.

@node racket-logger-warning-face
@subsection racket-logger-warning-face

Face for @ref{racket-logger-mode} warning level.

@node racket-logger-info-face
@subsection racket-logger-info-face

Face for @ref{racket-logger-mode} info level.

@node racket-logger-debug-face
@subsection racket-logger-debug-face

Face for @ref{racket-logger-mode} debug level.

@c Emacs 25.2.2 (Org mode 8.2.10)
@bye