diff options
Diffstat (limited to 'configs/shared/emacs/.emacs.d/elpa/haskell-mode-20180913.348/haskell-mode.info')
| -rw-r--r-- | configs/shared/emacs/.emacs.d/elpa/haskell-mode-20180913.348/haskell-mode.info | 2457 |
1 files changed, 2457 insertions, 0 deletions
diff --git a/configs/shared/emacs/.emacs.d/elpa/haskell-mode-20180913.348/haskell-mode.info b/configs/shared/emacs/.emacs.d/elpa/haskell-mode-20180913.348/haskell-mode.info new file mode 100644 index 000000000000..65bb8b00aaae --- /dev/null +++ b/configs/shared/emacs/.emacs.d/elpa/haskell-mode-20180913.348/haskell-mode.info @@ -0,0 +1,2457 @@ +This is haskell-mode.info, produced by makeinfo version 6.5 from +haskell-mode.texi. + +This manual is for Haskell mode, version 16.1-git + + Copyright © 2013-2017 Haskell Mode contributors. + + Permission is granted to copy, distribute and/or modify this + document under the terms of the GNU Free Documentation License + (http://www.gnu.org/licenses/fdl.html), Version 1.3 or any later + version published by the Free Software Foundation; with no + Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. +INFO-DIR-SECTION Emacs +START-INFO-DIR-ENTRY +* Haskell Mode: (haskell-mode). Haskell Development Environment for Emacs(en) +END-INFO-DIR-ENTRY + + +File: haskell-mode.info, Node: Top, Next: Introduction, Up: (dir) + +Haskell Mode +************ + +Haskell Mode is an Haskell development Environment for GNU Emacs version +24.3 or later. It provides syntax-based indentation, font locking, +editing cabal files, and supports running an inferior Haskell +interpreter (e.g. GHCi). + +* Menu: + +* Introduction:: An introduction to Haskell Mode +* Installation:: How to get started +* Editing Haskell Code:: How to edit code +* Syntax highlighting:: Haskell Mode has colors +* Completion support:: Autocomplete +* Unicode support:: How to use Unicode +* Indentation:: Notes about indentation +* External indentation:: Other ways to indent code +* Autoformating:: Using external formatters +* Module templates:: Module templates +* Declaration scanning:: How to navigate in a source file +* Compilation:: How to compile +* Interactive Haskell:: How to interact with GHCi +* Editing Cabal files:: Cabal support +* Browsing Haddocks:: Using ‘w3m’ to browse documentation +* Spell checking strings and comments:: Using ‘flyspell-prog-mode’ +* Aligning code:: Aligning code using ‘align-regexp’ +* Rectangular commands:: Manage indentation manually +* REPL:: GHCi REPL +* Collapsing Haskell code:: View more code on screen +* Getting Help and Reporting Bugs:: How to improve Haskell Mode +* Concept index:: Index of Haskell Mode concepts +* Function index:: Index of commands +* Variable index:: Index of options and types + + +File: haskell-mode.info, Node: Introduction, Next: Installation, Prev: Top, Up: Top + +1 Introduction +************** + +“Haskell Mode” is a major mode providing a convenient environment for +editing Haskell (http://www.haskell.org) programs. + + Some of its major features are: + + • Syntax highlighting (font lock), + • automatic semi-intelligent indentation, + • on-the-fly documentation, + • interaction with inferior GHCi/Hugs instance, + • project building with cabal and stack + • scanning declarations and placing them in a menu. + + The name Haskell Mode refers to the whole collection of modules in +this package. There is specifically a file ‘haskell-mode.el’ which +defines a major mode called ‘haskell-mode’. Generally, in this +documentation they will be distinguished by normal font and title case +(Haskell Mode) and code font (‘haskell-mode’). + +1.1 History +=========== + +‘haskell-mode’ has a long history. It goes all the way back to 1992. +Since then, it has received many contributions in many forms. Some +design choices that remain in haskell-mode today are historical. Some +modules are outdated or no longer used, or are used by a few people. + + Historically there hasn’t been a single individual or set of +individuals directing the package’s architecture for a long period of +time, rather, patches and new modules were accepted in liberally and we +are left with a box full of interesting toys that may or may not work. + + As of 2016 Haskell Mode is coordinated using Github at +<https://github.com/haskell/haskell-mode>. + + +File: haskell-mode.info, Node: Installation, Next: Editing Haskell Code, Prev: Introduction, Up: Top + +2 Installation +************** + +Haskell Mode is distributed as a package in MELPA repository +(https://melpa.org). To use MELPA as Emacs package archive do the +following: + + 1. Customize ‘package-archives’ using + M-x customize-option RET package-archives + 2. Use ‘INS’ to add new archive, use: + Archive name: melpa-stable + URL or directory name: http://stable.melpa.org/packages/ + 3. Fetch new packages using: + M-x package-refresh-contents + 4. Install Haskell Mode using: + M-x package-install RET haskell-mode RET + + Voila! ‘haskell-mode’ is installed! You should be able to edit +Haskell source code in color now. + + The above steps should result in the following snippet in your +‘.emacs’: + + (require 'package) + (custom-set-variables + ;; custom-set-variables was added by Custom. + ;; If you edit it by hand, you could mess it up, so be careful. + ;; Your init file should contain only one such instance. + ;; If there is more than one, they won't work right. + '(package-archives + (quote + (("gnu" . "http://elpa.gnu.org/packages/") + ("melpa-stable" . "http://stable.melpa.org/packages/"))))) + + Haskell Mode supports GNU Emacs versions 24.3+, including 25 +(snapshot). + + Haskell Mode is available from melpa-stable (releases) +(http://stable.melpa.org) and melpa (git snapshots) (http://melpa.org). + + Other means of obtaining ‘haskell-mode’ include el-get +(https://github.com/dimitri/el-get), Emacs Prelude +(https://github.com/bbatsov/prelude) and Debian package +(https://packages.debian.org/search?keywords=haskell-mode). + + Last version of ‘haskell-mode’ that supported Emacs 23, 24.1, and +24.2 is ‘haskell-mode’ 13.16 available at +<https://github.com/haskell/haskell-mode/releases/tag/v13.16>. + +2.1 Customizing +=============== + +Most of Haskell Mode’s settings are configurable via customizable +variables (*note (emacs)Easy Customization::, for details). You can use +‘M-x customize-group <RET> haskell’ to browse the ‘haskell’ +customization sub-tree. + + One of the important setting you should customize is the +‘haskell-mode-hook’ variable (*note (emacs)Hooks::) which gets run right +after the ‘haskell-mode’ major mode is initialized for a buffer. You +can customize ‘haskell-mode-hook’ by + + M-x customize-variable RET haskell-mode-hook + + There you can enable or disable a couple of predefined options or add +any function to the list. + + +File: haskell-mode.info, Node: Editing Haskell Code, Next: Syntax highlighting, Prev: Installation, Up: Top + +3 Editing Haskell Code +********************** + +Haskell Mode as one of its components provides a major mode for editing +Haskell source code called ‘haskell-mode’, which gave the name to the +whole project. There is a derived mode provided called +‘literate-haskell-mode’ that support Literate Haskell source code both +in Bird and in Latex forms. + + Haskell Mode supports files with the following extensions: + +‘.hs’ + official file extension for Haskell files. Haskell Mode out of the + box supports most of GHC extensions. +‘.lhs’ + official file extension for Literate Haskell files. Both Bird and + Latex styles are supported. +‘.hsc’ + Haskell interfaces to C code used by hsc2hs + (http://www.haskell.org/ghc/docs/latest/html/users_guide/hsc2hs.html) + pre-processor. +‘.cpphs’ + Haskell source with CPP pragmas used with cpphs + (http://projects.haskell.org/cpphs) pre-processor. +‘.c2hs’ + Haskell FFI bindings to C libraries used with c2hs + (https://github.com/haskell/c2hs) pre-processor. + + Haskell Mode offers many productivity tools described in following +chapters in this manual. + +3.1 Managing imports +==================== + +There are a few functions for managing imports. + +3.1.1 Jump to imports +--------------------- + +To jump to your import list, run + + ‘M-x’ ‘haskell-navigate-imports’ + + It’s nicer to have a keybinding to do this, for example: + + (define-key haskell-mode-map (kbd "<f8>") 'haskell-navigate-imports) + + You can hit it repeatedly to jump between groups of imports. It will +cycle. + +3.1.2 Format imports +-------------------- + +To generally format (sort, align) your imports, you can run + + ‘M-x’ ‘haskell-mode-format-imports’ + + Or ‘C-c C-,’. + +3.1.3 Sort imports +------------------ + +To just sort imports, jump to an import section and run + + ‘M-x’ ‘haskell-sort-imports’ + +3.1.4 Align imports +------------------- + +To just align imports, jump to an import section and run + + ‘M-x’ ‘haskell-align-imports’ + +3.1.5 stylish-haskell +--------------------- + +As an alternative to the elisp functions described above, haskell-mode +can use the program stylish-haskell +(http://hackage.haskell.org/package/stylish-haskell) to format imports. +You can set this behavior by typing: ‘M-x’ ‘customize-variable’ ‘RET’ +‘haskell-stylish-on-save’. You can install ‘stylish-haskell’ by running +‘stack install stylish-haskell’, or if you have not installed ‘stack’, +‘cabal install stylish-haskell’. + +3.2 Haskell Tags +================ + +‘haskell-mode’ can generate tags when saving source files. To generate +tags ‘haskell-mode’ uses external program — Hasktags +(https://github.com/MarcWeber/hasktags) (wiki-article +(https://wiki.haskell.org/Tags)). To turn on tags generatation +customize or set to ‘t’ ‘haskell-tags-on-save’ variable. Also, you may +find useful to revert tags tables automatically, this can be done by +customizing ‘tags-revert-without-query’ variable (either globally or for +Haskell buffers only). + +3.3 Profiling and Debugging support +=================================== + +When profiling code with GHC, it is often useful to add cost centres +(https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/profiling.html#cost-centres) +by hand. These allow finer-grained information about program behavior. +‘haskell-mode’ provides the function ‘haskell-mode-toggle-scc-at-point’ +to make this more convenient. It will remove an SCC annotation at point +if one is present, or add one if point is over whitespace. By default +it is bound to ‘C-c C-s’. + + +File: haskell-mode.info, Node: Syntax highlighting, Next: Completion support, Prev: Editing Haskell Code, Up: Top + +4 Syntax highlighting +********************* + +‘haskell-mode’ supports “syntax highlighting” via Emacs’ Font Lock minor +mode which should be enabled by default in current Emacsen. *Note +(emacs)Font Lock::, for more information on how to control +‘font-lock-mode’. + + Syntax highlighting facilities parse strings and string escape +sequences and are able to highlight unrecognized constructs. + + Haskell Mode shows keywords, identifiers, operators, constructors and +types in different colors. + + There is also support to use mode-specific syntax highlighing for +quasiquotes. + + At this point quasi quotes for HTML, XML, shell scripts, Hamlet +templates and SQL are supported out of the box. Customize +‘haskell-font-lock-quasi-quote-modes’ to make sure your quoters are +supported. + + The following customization variables are responsible for faces +applied: + + ‘’ ‘haskell-keyword-face’: for keywords + ‘’ ‘haskell-type-face’: for type names and type class names + ‘’ ‘haskell-constructor-face’: for constructors + ‘’ ‘haskell-definition-face’: function and operator name at the + definition place + ‘’ ‘haskell-operator-face’: operators + ‘’ ‘haskell-pragma-face’: GHC pragmas + ‘’ ‘haskell-literate-comment-face’: literate comments + ‘’ ‘haskell-quasi-quote-face’: quasi quotes unless using mode + specific highlighting + ‘’ ‘haskell-c2hs-hook-pair-face’: c2hs hooks + ‘’ ‘haskell-c2hs-hook-name-face’: c2hs hook names + + All the above are available for customization. + + GHC quasi quote syntax is ambiguous with list comprehension therefore +syntax highlighting might get confused with situations like these: + + result = [html| html <- htmlList] + result = [html| <html><body>...</body></html> |] + + Please use spaces around a list comprehension variable to make this +unambiguous. Any of the following will work: + + result = [ html| html <- htmlList] + result = [html | html <- htmlList] + + GHC’s ambiguity is an accident of the past but it is unlikely to be +fixed due to backward compatibility baggage. + + +File: haskell-mode.info, Node: Completion support, Next: Unicode support, Prev: Syntax highlighting, Up: Top + +5 Completion support +******************** + +‘haskell-mode’ can complete symbols, pragma directives, language +extensions, and language keywords out-of-box. ‘haskell-mode’ completes +identifiers (symbols) using tags (see “Tags”), however you can get more +precise completions with ‘haskell-interactive-mode’. In interactive +mode completion candidates are produced by querying GHCi REPL. + + If ‘haskell-interactive-mode’ is enabled and working Haskell mode +provides completions for import statements taking into account currently +loaded and available packages. Also it completes symbols querying REPL +with ‘:complete’ command, hence completion candidate list also includes +symbols from imported modules. + + Unfortunatelly, it is not possible to provide candidates for +identifiers defined locally in ‘let’ and ‘where’ blocks even in +interactive mode. But if you’re using company-mode +(http://company-mode.github.io/) you can override ‘company-backends’ +variable for Haskell buffers to combine completion candidates from +completion-at-point function (‘company-capf’ backend) and dynamic +abbrevs. ‘company-mode’ provides special backend for dabbrev code +completions, namely ‘company-dabbrev-code’. To combine completions from +diffrent backends you can create grouped backends, it is very easy — a +grouped backend is just a list of backends, for example: + + (add-hook 'haskell-mode-hook + (lambda () + (set (make-local-variable 'company-backends) + (append '((company-capf company-dabbrev-code)) + company-backends)))) + + If you use a GHCi version prior to 8.0.1 you might want to set +‘haskell-completions-complete-operators’ to ‘nil’, if you experience +major slowdown while trying to complete after an Haskell operator (See +GHC-Bug 10576 (https://ghc.haskell.org/trac/ghc/ticket/10576)). + + +File: haskell-mode.info, Node: Unicode support, Next: Indentation, Prev: Completion support, Up: Top + +6 Unicode support +***************** + +See the Haskell Wiki’s entry on Unicode Symbols +(http://www.haskell.org/haskellwiki/Unicode-symbols) for general +information about Unicode support in Haskell. + + As Emacs supports editing files containing Unicode out of the box, so +does Haskell Mode. As an add-on, Haskell Mode includes the +‘haskell-unicode’ input method which allows you to easily type a number +of Unicode symbols that are useful when writing Haskell code; *Note +(emacs)Input Methods::, for more details. + + To automatically enable the ‘haskell-unicode’ input method in +haskell-mode buffers use ‘M-x customize-variable <RET> +haskell-mode-hook’ or put the following code in your ‘.emacs’ file: + + (add-hook 'haskell-mode-hook 'turn-on-haskell-unicode-input-method) + +To temporarily enable this input method for a single buffer you can use +‘M-x turn-on-haskell-unicode-input-method’. + + When the ‘haskell-unicode’ input method is active, you can simply +type ‘->’ and it is immediately replaced with ‘→’. Use ‘C-\’ to toggle +the input method. To see a table of all key sequences use ‘M-x +describe-input-method <RET> haskell-unicode’. A sequence like ‘<=’ is +ambiguous and can mean either ‘⇐’ or ‘≤’. Typing it presents you with a +choice. Type ‘1’ or ‘2’ to select an option or keep typing to use the +default option. + + Currently defined sequences are listed in the following table: + +SequenceUnicode SequenceUnicode SequenceUnicode SequenceUnicode +---------------------------------------------------------------------------- +alpha α Alpha Α beta β Beta Β +gamma γ Gamma Γ delta δ Delta Δ +epsilonε EpsilonΕ zeta ζ Zeta Ζ +eta η Eta Η theta θ Theta Θ +iota ι Iota Ι kappa κ Kappa Κ +lambda λ Lambda Λ lamda λ Lamda Λ +mu μ Mu Μ nu ν Nu Ν +xi ξ Xi Ξ omicronο OmicronΟ +pi π Pi Π rho ρ Rho Ρ +sigma σ Sigma Σ tau τ Tau Τ +upsilonυ UpsilonΥ phi φ Phi Φ +chi χ Chi Χ psi ψ Psi Ψ +omega ω Omega Ω digammaϝ DigammaϜ +san ϻ San Ϻ qoppa ϙ Qoppa Ϙ +sampi ϡ Sampi Ϡ stigma ϛ Stigma Ϛ +heta ͱ Heta Ͱ sho ϸ Sho Ϸ +|A| 𝔸 |B| 𝔹 |C| ℂ |D| 𝔻 +|E| 𝔼 |F| 𝔽 |G| 𝔾 |H| ℍ +|I| 𝕀 |J| 𝕁 |K| 𝕂 |L| 𝕃 +|M| 𝕄 |N| ℕ |O| 𝕆 |P| ℙ +|Q| ℚ |R| ℝ |S| 𝕊 |T| 𝕋 +|U| 𝕌 |V| 𝕍 |W| 𝕎 |X| 𝕏 +|Y| 𝕐 |Z| ℤ |gamma|ℽ |Gamma|ℾ +|pi| ℼ |Pi| ℿ :: ∷ forall ∀ +exists ∃ -> → <- ← => ⇒ +~> ⇝ <~ ⇜ && ∧ || ∨ +== ≡ /= ≢, ≠ <= ≤ >= ≥ +/< ≮ /> ≯ * ⋅ elem ∈ +notElem∉ member ∈ notMember∉ union ∪ +intersection∩ isSubsetOf⊆ isProperSubsetOf⊂ <<< ⋘ +>>> ⋙ <| ⊲ |> ⊳ >< ⋈ +mappend⊕ . ∘ undefined⊥ := ≔ +=: ≕ =def ≝ =? ≟ ... … +_0 ₀ _1 ₁ _2 ₂ _3 ₃ +_4 ₄ _5 ₅ _6 ₆ _7 ₇ +_8 ₈ _9 ₉ ^0 ⁰ ^1 ¹ +^2 ² ^3 ³ ^4 ⁴ ^5 ⁵ +^6 ⁶ ^7 ⁷ ^8 ⁸ ^9 ⁹ + + If you don’t like the highlighting of partially matching tokens you +can turn it off by setting ‘input-method-highlight-flag’ to ‘nil’ via +‘M-x customize-variable’. + + +File: haskell-mode.info, Node: Indentation, Next: External indentation, Prev: Unicode support, Up: Top + +7 Indentation +************* + +In Haskell, code indentation has semantic meaning as it defines the +block structure. Haskell also supports braces and semicolons notation +for conveying the block structure. However, most Haskell programs +written by humans use indentation for block structuring. + + Haskell Mode ships with two indentation modes: + + • ‘haskell-indentation-mode’ (default). + + This is a semi-intelligent indentation mode doing a decent job at + recognizing Haskell syntactical constructs. It is based on a + recursive descent Haskell parser. ‘TAB’ selects the next potential + indentation position, ‘S-TAB’ selects the previous one. If a block + is selected you can use ‘TAB’ to indent the block more and ‘S-TAB’ + to indent the block less. + + When ‘electric-indent-mode’ is enabled or the variable + ‘haskell-indentation-electric-flag’ is non-nil, the insertion of + some characters (by default ‘,’ ‘;’ ‘)’ ‘}’ ‘]’) may trigger auto + reindentation under appropriate conditions. See the documentation + of ‘haskell-indentation-common-electric-command’ for more details. + + • ‘haskell-indent-mode’ (optional). + + This is a semi-intelligent indentation mode doing a decent job at + recognizing Haskell syntactical constructs. It is based on a + decision table. Sadly it is no longer developed and does not + recognize newer Haskell syntax. ‘TAB’ cycles through all available + indentation positions. + + To use ‘haskell-indent-mode’, add this to your ‘~/.emacs’ file: + + (add-hook 'haskell-mode-hook 'turn-on-haskell-indent) + + Note that ‘turn-on-haskell-indent’ will disable + ‘haskell-indentation-mode’. + + For general information about indentation support in GNU Emacs, *note +(emacs)Indentation::. + +7.1 Rectangle Commands +====================== + +GNU Emacs provides so-called “rectangle commands” which operate on +rectangular areas of text, which are particularly useful for languages +with a layout rule such as Haskell. *Note (emacs)Rectangles::, to learn +more about rectangle commands. + + Moreover, CUA mode (*note (emacs)CUA Bindings::) provides enhanced +rectangle support with visible rectangle highlighting. When CUA mode is +active, you can initiate a rectangle selection by ‘C-RET’ and extend it +simply by movement commands. You don’t have to enable full CUA mode to +benefit from these enhanced rectangle commands; you can activate CUA +selection mode (without redefining ‘C-x’,‘C-c’,‘C-v’, and ‘C-z’) by +calling ‘M-x cua-selection-mode’ (or adding ‘(cua-selection-mode nil)’ +to your ‘haskell-mode-hook’). + +7.2 Region indent is a no-op +============================ + +There is a ‘indent-region’ function that supposedly could be used to +indent code region without changing its semantics. Sadly it does not +work that way because usual use case for ‘indent-region’ is: + + 1. Alter first line of code in region. + 2. Call ‘indent-region’ to fix indentation for remaining lines. + + Note that between 1 and 2 program is already semantically broken and +knowing how to indent it preserving semantic from before step 1 would +require time travel. + + To stay on the safe side ‘indent-region-function’ is bound to a no-op +in ‘haskell-mode’. + + +File: haskell-mode.info, Node: External indentation, Next: Autoformating, Prev: Indentation, Up: Top + +8 Other ways to indent code +*************************** + +8.1 Indentation with tabs, not spaces +===================================== + +Some projects require indenting code with tabs and forbid indenting it +with spaces. For hacking on such projects, check out +haskell-tab-indent-mode +(https://spwhitton.name/tech/code/haskell-tab-indent). + +8.2 Structured indentation +========================== + +Another alternative is to install structured-haskell-mode +(https://github.com/chrisdone/structured-haskell-mode). which indents +code by parsing the code with a full Haskell parser and deciding where +to indent based on that. + + +File: haskell-mode.info, Node: Autoformating, Next: Module templates, Prev: External indentation, Up: Top + +9 Using external formatters +*************************** + +You can enable stylish-haskell +(https://github.com/jaspervdj/stylish-haskell) by installing it: + + $ cabal install stylish-haskell + + And by enabling it with a customization + + (custom-set-variables + '(haskell-stylish-on-save t)) + + Now when you run ‘save-buffer’ (or ‘C-x C-s’) the module will be +automatically formatted. + + Alternatively, you can run the function directly on demand with ‘M-x’ +‘haskell-mode-stylish-buffer’. + + +File: haskell-mode.info, Node: Module templates, Next: Declaration scanning, Prev: Autoformating, Up: Top + +10 Module templates +******************* + +To enable auto-insertion of module templates, enable: + + (add-hook 'haskell-mode-hook 'haskell-auto-insert-module-template) + + When you open a file called ‘Foo.hs’, it will auto-insert + + -- | + + module Foo where + + And put your cursor in the comment section. + + +File: haskell-mode.info, Node: Declaration scanning, Next: Compilation, Prev: Module templates, Up: Top + +11 Declaration scannning +************************ + +‘haskell-decl-scan-mode’ is a minor mode which performs declaration +scanning and provides ‘M-x imenu’ support (*note (emacs)Imenu:: for more +information). + + For non-literate and TeX-style literate scripts, the common +convention that top-level declarations start at the first column is +assumed. For Bird-style literate scripts, the common convention that +top-level declarations start at the third column, ie. after ‘> ’, is +assumed. + + When ‘haskell-decl-scan-mode’ is active, the standard Emacs top-level +definition movement commands (*note (emacs)Moving by Defuns::) are +enabled to operate on Haskell declarations: + +‘C-M-a’ + Move to beginning of current or preceding declaration + (‘beginning-of-defun’). + +‘C-M-e’ + Move to end of current or following declaration (‘end-of-defun’). + +‘C-M-h’ + Select whole current or following declaration (‘mark-defun’). + + Moreover, if enabled via the option +‘haskell-decl-scan-add-to-menubar’, a menu item “Declarations” is added +to the menu bar listing the scanned declarations and allowing to jump to +declarations in the source buffer. + + It’s recommended to have font lock mode enabled (*note (emacs)Font +Lock::) as ‘haskell-decl-scan-mode’ ignores text highlighted with +‘font-lock-comment-face’. + + As usual, in order to activate ‘haskell-decl-scan-mode’ automatically +for Haskell buffers, add ‘haskell-decl-scan-mode’ to +‘haskell-mode-hook’: + + (add-hook 'haskell-mode-hook 'haskell-decl-scan-mode) + + ‘haskell-decl-scan-mode’ enables the use of features that build upon +‘imenu’ support such as Speedbar Frames (*note (emacs)Speedbar::) or the +global “Which Function” minor mode (*note (emacs)Which Function::). + + In order to enable ‘which-function-mode’ for Haskell buffers you need +to add the following to your Emacs initialization: + + (eval-after-load "which-func" + '(add-to-list 'which-func-modes 'haskell-mode)) + +11.1 Speedbar +============= + +Haskell-mode comes with declaration scanning support. This means that +if you enable Haskell support for speedbar: + + (speedbar-add-supported-extension ".hs") + + And open speedbar with + + ‘M-x speedbar’ + + It gives a listing of each module and under each module: + + Imports + Instances + Data types + Classes + Bindings + + You will get a bar that looks like this: + +~/Projects/ace/src/ACE/ +0:<+> Types +0:[+] Combinators.hs +0:[-] Datalog.hs +1: {-} Classes +2: > ToTerm +1: {-} Imports +2: > ACE.Types.Syntax +2: > Database.Datalog +1: {-} Instances +2: {+} ToTerm A +2: {+} ToTerm Co to ToTerm Gen +2: {+} ToTerm Intransitive to ToTerm N +2: {+} ToTerm P +2: {+} ToTerm Quotation to ToTerm Un +2: {+} ToTerm V +0:[-] Html.hs +1: {+} Imports +1: {+} Instances +1: > mtoMarkup +1: > toMarkupm +1: > wrap +0:[-] Parsers.hs +1: {+} Imports +1: {-} Datatypes +2: > ACEParser +0:[+] Pretty.hs +0:[+] Tokenizer.hs + + The hierarchy is expandable/collapsible and each entry will jump to +the line in the right file when clicked/selected. + + +File: haskell-mode.info, Node: Compilation, Next: Interactive Haskell, Prev: Declaration scanning, Up: Top + +12 Compilation +************** + +Haskell mode comes equipped with a specialized “Compilation mode” +tailored to GHC’s compiler messages with optional support for Cabal +projects. *Note (emacs)Compilation Mode::, for more information about +the basic commands provided by the Compilation mode which are available +in the Haskell compilation sub-mode as well. The additional features +provided compared to Emacs’ basic Compilation mode are: + + • DWIM-style auto-detection of compile command (including support for + CABAL projects) + • Support for GHC’s compile messages and recognizing error, warning + and info source locations (including ‘-ferror-spans’ syntax) + • Support for filtering out GHC’s uninteresting ‘Loading package...’ + linker messages + + In order to use it, invoke the ‘haskell-compile’ command instead of +‘compile’ as you would for the ordinary Compilation mode. It’s +recommended to bind ‘haskell-compile’ to a convenient key binding. For +instance, you can add the following to your Emacs initialization to bind +‘haskell-compile’ to ‘C-c C-c’. + + (eval-after-load "haskell-mode" + '(define-key haskell-mode-map (kbd "C-c C-c") 'haskell-compile)) + + (eval-after-load "haskell-cabal" + '(define-key haskell-cabal-mode-map (kbd "C-c C-c") 'haskell-compile)) + +The following description assumes that ‘haskell-compile’ has been bound +to ‘C-c C-c’. + + When invoked, ‘haskell-compile’ tries to guess how to compile the +Haskell program your currently visited buffer belongs to, by searching +for a ‘.cabal’ file in the current of enclosing parent folders. If a +‘.cabal’ file was found, the command defined in the +‘haskell-compile-cabal-build-command’ option is used. Note that to +compile a ‘stack’ based project you will need to set this variable to +‘stack build’. As usual you can do it using ‘M-x customize-variable’ or +with: + + (setq haskell-compile-cabal-build-command "stack build") + + Moreover, when requesting to compile a ‘.cabal’-file is detected and +a negative prefix argument (e.g. ‘C-- C-c C-c’) was given, the +alternative ‘haskell-compile-cabal-build-command-alt’ is invoked. By +default, ‘haskell-compile-cabal-build-command-alt’ contains a ‘cabal +clean -s’ command in order to force a full rebuild. + + Otherwise if no ‘.cabal’ could be found, a single-module compilation +is assumed and ‘haskell-compile-command’ is used (_if_ the currently +visited buffer contains Haskell source code). + + You can also inspect and modify the compile command to be invoked +temporarily by invoking ‘haskell-compile’ with a prefix argument (e.g. +‘C-u C-c C-c’). If later-on you want to recompile using the same +customized compile command, invoke ‘recompile’ (bound to ‘g’) inside the +‘*haskell-compilation*’ buffer. + +12.1 Keybindings +================ + +Key Function +binding +------------ +TAB compilation-next-error + +RET compile-goto-error + +C-o compilation-display-error + +SPC scroll-up-command + +- negative-argument + +0 digit-argument +.. +9 +< beginning-of-buffer + +> end-of-buffer + +? describe-mode + +g recompile + +h describe-mode + +q quit-window + +DEL scroll-down-command + +S-SPC scroll-down-command + +<backtab>compilation-previous-error + +<follow-link>mouse-face + +<mouse-2>compile-goto-error + +<remap>Prefix + Command + +M-n compilation-next-error + +M-p compilation-previous-error + +M-{ compilation-previous-file + +M-} compilation-next-file + +C-c compile-goto-error +C-c +C-c next-error-follow-minor-mode +C-f +C-c kill-compilation +C-k + + +File: haskell-mode.info, Node: Interactive Haskell, Next: Editing Cabal files, Prev: Compilation, Up: Top + +13 Interactive Haskell +********************** + +REPL (read–eval–print loop) is provided both via Comint +(‘inferior-haskell-mode’) and an adhoc way called +‘haskell-interactive-mode’. The Comint based ‘inferior-haskell-mode’ is +just the REPL, it comes with the standard key bindings(like ‘ielm’ or +‘eshell’). + + ‘haskell-interactive-mode’ comes with a different set of features: + + • Separate sessions per Cabal project ‘haskell-session.el’. + • A new inferior Haskell process handling code ‘haskell-process.el’. + • New REPL implementation similiar to SLIME/IELM + • Navigatable error overlays ‘haskell-interactive-mode.el’. + + With ‘haskell-interactive-mode’, each Haskell source buffer is +associated with at most one GHCi session, so when you call +‘haskell-process-load-file’ for a Haskell source buffer which has no +session associated yet, you’re asked which GHCi session to create or +associate with. + +13.1 Goto Error +=============== + +In a Haskell source buffer associated with a GHCi session, errors that +prevent the file from loading are highlighted with ‘haskell-error-face’. +You can move between these error lines with + +‘M-n’ + is bound to ‘haskell-goto-next-error’ +‘M-p’ + is bound to ‘haskell-goto-prev-error’ +‘C-c M-p’ + is bound to ‘haskell-goto-first-error’ + +13.2 Using GHCi 8+ or GHCi-ng +============================= + +If you use either of the above, then you can use these functions: + + (define-key interactive-haskell-mode-map (kbd "M-.") 'haskell-mode-goto-loc) + (define-key interactive-haskell-mode-map (kbd "C-c C-t") 'haskell-mode-show-type-at) + + You have to load the module before it works, after that it will +remember for the current GHCi session. + +13.3 Customizing +================ + +What kind of Haskell REPL ‘haskell-interactive-mode’ will start up +depends on the value of ‘haskell-process-type’. This can be one of the +symbols ‘auto’, ‘ghci’, ‘cabal-repl’, ‘cabal-new-repl’, or ‘stack-ghci’. +If it’s ‘auto’, the directory contents and available programs will be +used to make a best guess at the process type. The actual process type +will then determine which variables ‘haskell-interactive-mode’ will +access to determine the program to start and its arguments: + + • If it’s ‘ghci’, ‘haskell-process-path-ghci’ and + ‘haskell-process-args-ghci’ will be used. + • If it’s ‘cabal-repl’, ‘haskell-process-path-cabal’ and + ‘haskell-process-args-cabal-repl’. + • If it’s ‘cabal-new-repl’, ‘haskell-process-path-cabal’ and + ‘haskell-process-args-cabal-new-repl’. + • If it’s ‘stack-ghci’, ‘haskell-process-path-stack’ and + ‘haskell-process-args-stack-ghci’ will be used. + + With each of these pairs, the the ‘haskell-process-path-...’ variable +needs to be a string specifying the program path, or a list of strings +where the first element is the program path and the rest are initial +arguments. The ‘haskell-process-args-...’ is a list of strings +specifying (further) command-line arguments. + +13.4 Haskell Interactive Mode Setup +=================================== + +The most straight-forward way to get setup with Interactive Mode is to +bind the right keybindings and set some customizations. This page +contains a good base setup. + + To enable the minor mode which activates keybindings associated with +interactive mode, use: + + (require 'haskell-interactive-mode) + (require 'haskell-process) + (add-hook 'haskell-mode-hook 'interactive-haskell-mode) + +13.4.1 Customizations +--------------------- + +This enables some handy and benign features. + + (custom-set-variables + '(haskell-process-suggest-remove-import-lines t) + '(haskell-process-auto-import-loaded-modules t) + '(haskell-process-log t)) + +13.4.2 Haskell-mode bindings +---------------------------- + +This gives the basic ways to start a session. In a Haskell buffer: + + • Run ‘C-`’ to make a REPL open, this will create a session, start + GHCi, and open the REPL. + • Or: run ‘C-c C-l’ to load the file. This will first try to start a + session as the previous command does. + • Or: run any command which requires a running session. It will + always prompt to create one if there isn’t one already for the + current project. + + (define-key haskell-mode-map (kbd "C-c C-l") 'haskell-process-load-or-reload) + (define-key haskell-mode-map (kbd "C-`") 'haskell-interactive-bring) + (define-key haskell-mode-map (kbd "C-c C-t") 'haskell-process-do-type) + (define-key haskell-mode-map (kbd "C-c C-i") 'haskell-process-do-info) + (define-key haskell-mode-map (kbd "C-c C-c") 'haskell-process-cabal-build) + (define-key haskell-mode-map (kbd "C-c C-k") 'haskell-interactive-mode-clear) + (define-key haskell-mode-map (kbd "C-c c") 'haskell-process-cabal) + +13.4.3 Cabal-mode bindings +-------------------------- + +The below commands pretty much match the ones above, but are handy to +have in cabal-mode, too: + + (define-key haskell-cabal-mode-map (kbd "C-`") 'haskell-interactive-bring) + (define-key haskell-cabal-mode-map (kbd "C-c C-k") 'haskell-interactive-mode-clear) + (define-key haskell-cabal-mode-map (kbd "C-c C-c") 'haskell-process-cabal-build) + (define-key haskell-cabal-mode-map (kbd "C-c c") 'haskell-process-cabal) + +13.4.4 GHCi process type +------------------------ + +By default ‘haskell-process-type’ is set to ‘auto’. It is smart enough +to pick the right type based on your project structure and installed +tools, but in case something goes funky or you want to explicitly set +the process type and ignore the inferred type, you can customize this +setting by running ‘M-x’ ‘customize-variable’ ‘RET’ +‘haskell-process-type’ ‘RET’, or by setting the code: + + (custom-set-variables + '(haskell-process-type 'cabal-repl)) + + Here is a list of available process types: + + • ghci + • cabal-repl + • cabal-new-repl + • cabal-dev + • cabal-ghci + • stack-ghci + + Please, check the documentation for ‘haskell-process-type’ to see how +the real type is guessed, when it’s set to ‘auto’. + +13.4.5 Troubleshooting +---------------------- + +Launching your GHCi process can fail when you’re first getting setup, +depending on the type you choose. If it does fail to launch, switch to +the buffer ‘*haskell-process-log*’ and see what’s up. The buffer +contains a log of incoming/outgoing messages to the GHCi process. + +13.5 Haskell Interactive Mode Tags Using GHCi +============================================= + +You can bind the following to use GHCi to find definitions of things: + + (define-key haskell-mode-map (kbd "M-.") 'haskell-mode-jump-to-def) + + The one problem with this approach is that if your code doesn’t +compile, GHCi doesn’t give any location info. So you need to make sure +your code compiles and the modules you want to jump to are loaded +byte-compiled. + + Note: I think that when you restart GHCi you lose location +information, even if you have the ‘.o’ and ‘.hi’ files lying around. +I’m not sure. But sometimes ‘:i foo’ will give ‘foo is defined in Bar’ +rather than ‘foo is defined in /foo/Bar.hs:123:23’. + + Alternatively, you can use tags generation, which doesn’t require a +valid compile. + +13.5.1 Tags Setup +----------------- + +Make sure to install ‘hasktags’. + + $ cabal install hasktags + + Then add the customization variable to enable tags generation on +save: + + (custom-set-variables + '(haskell-tags-on-save t)) + + And make sure ‘hasktags’ is in your ‘$PATH’ which Emacs can see. + +13.5.2 Generating tags +---------------------- + +Now, every time you run ‘save-buffer’ (‘C-x C-s’), there is a hook that +will run and generate Emacs *Note (emacs)Tags:: for the whole project +directory. The resulting file will be called ‘TAGS’. + + WARNING: You should be careful that your project root isn’t your home +directory or something, otherwise it will traverse all the way down and +take an impossibly long time. + +13.5.3 Jumping to tags +---------------------- + +Bind the following keybinding: + + (define-key haskell-mode-map (kbd "M-.") 'haskell-mode-tag-find) + + To jump to the location of the top-level identifier at point, run +‘M-x’ ‘haskell-mode-tag-find’ or ‘M-.’. + +13.5.4 Hybrid: GHCi and fallback to tags +---------------------------------------- + +To use GHCi first and then if that fails to fallback to tags for +jumping, use: + + (define-key haskell-mode-map (kbd "M-.") 'haskell-mode-jump-to-def-or-tag) + +13.5.5 Troubleshooting tags +--------------------------- + +Sometimes a ‘TAGS’ file is deleted (by you or some other process). +Emacs will complain that it doesn’t exist anymore. To resolve this +simply do ‘M-x’ ‘tags-reset-tags-tables’. + +13.6 Sessions +============= + +All commands in Haskell Interactive Mode work within a session. +Consider it like a “project” or a “solution” in popular IDEs. It tracks +the root of your project and an associated process and REPL. + +13.6.1 Start a session +---------------------- + +To start a session run the following steps: + + • Open some Cabal or Haskell file. + • Run ‘C-`’ to make a REPL open, this will create a session, start + GHCi, and open the REPL. + • Or: run ‘C-c C-l’ to load the file. This will first try to start a + session as the previous command does. + • Or: run any command which requires a running session. It will + always prompt to create one if there isn’t one already for the + current project. + + It will prompt for a Cabal directory and a current directory. It +figures out where the cabal directory is and defaults for the current +directory, so you should be able to just hit RET twice. + +13.6.2 Switch a session +----------------------- + +Sometimes a particular file is used in two different sessions/projects. +You can run + + M-x haskell-session-change + + If it prompts you to make a new session, tell it no (that’s a bug). +It will ask you to choose from a list of sessions. + +13.6.3 Killing a session +------------------------ + +To kill a session you can run + + M-x haskell-session-kill + + Which will prompt to kill all associated buffers, too. Hit ‘n‘ to +retain them. + + Alternatively, you can switch to the REPL and just kill the buffer +normally with ‘C-x k RET’. It will prompt + + Kill the whole session (y or n)? + + You can choose ‘y’ to kill the session itself, or ‘n’ to just kill +the REPL buffer. You can bring it back with ‘M-x’ +‘haskell-interactive-bring’. + +13.6.4 Menu +----------- + +To see a list of all sessions you have open with some simple statistics +about memory usage, etc. run + + M-x haskell-menu + + For example: + + foo 14648 08:21:42 214MB /path/to/fpco/foo/ /path/to/fpco/foo/ ghci + bar 29119 00:22:03 130MB /path/to/bar/ /path/to/bar/ ghci + mu 22575 08:48:20 73MB /path/to/fpco/mu/ /path/to/fpco/mu/ ghci + +13.7 Compiling +============== + +There are a bunch of ways to compile Haskell modules. This page covers +a few of them. + +13.7.1 Load into GHCi +--------------------- + +To compile and load a Haskell module into GHCi, run the following + + M-x haskell-process-load + + Or ‘C-c C-l’. You’ll see any compile errors in the REPL window. + +13.7.2 Build the Cabal project +------------------------------ + +To compile the whole Cabal project, run the following + + M-x haskell-process-cabal-build + + Or ‘C-c C-c’. You’ll see any compile errors in the REPL window. + +13.7.3 Reloading modules +------------------------ + +To reload the current module, even when you’re in other modules, you can +run ‘C-u M-x’ ‘haskell-process-load-or-reload’ or ‘C-u C-c C-l’. It +will now reload that module whenever you run ‘C-c C-l’ in the future +from whatever module you’re in. To disable this mode, just run ‘C-u C-c +C-l’ again. + +13.7.4 Jumping to compile errors +-------------------------------- + +You can use the standard compile error navigation function ‘C-x `’ — +jump to the next error. + + Or you can move your cursor to an error in the REPL and hit ‘RET’ to +jump to it. + +13.7.5 Auto-removing imports +---------------------------- + +If the customization variable +‘haskell-process-suggest-remove-import-lines’ is enabled. + + (custom-set-variables + '(haskell-process-suggest-remove-import-lines t)) + + Building and loading modules which output warnings like, + + Warning: The import of `Control.Monad' is redundant + except perhaps to import instances from `Control.Monad' + To import instances alone, use: import Control.Monad() + + will prompt the user with + + > The import line `Control.Monad' is redundant. Remove? (y, n, c: comment out) + + If you answer + + • ‘y’: it will delete the import, but leave the empty line remaining + (this avoids messing with line positions in subsequent error + messages). + • ‘n’: it will leave the import. + • ‘c’: it will comment out the import (this is handy for when you + just want to temporarily hide an import). + +13.7.6 Auto-adding of modules to import +--------------------------------------- + +Enable the customization variable +‘haskell-process-suggest-hoogle-imports’. + + (custom-set-variables + '(haskell-process-suggest-hoogle-imports t)) + + Whenever GHC says something is not in scope, it will hoogle that +symbol. If there are results, it will prompt to add one of the modules +from Hoogle’s results. + + You need to make sure you’ve generated your Hoogle database properly. + +13.7.7 Auto-adding of extensions +-------------------------------- + +It you use an extension which is not enabled, GHC will often inform you. +For example, if you write: + + newtype X a = X (IO a) + deriving (Monad) + + Then you’ll see a message like: + + x.hs:13:13: Can't make a derived instance of `Monad X': … + `Monad' is not a derivable class + Try -XGeneralizedNewtypeDeriving for GHC's newtype-deriving extension + In the newtype declaration for `X' + + This ‘-XFoo’ pattern will be picked up and you will be prompted: + + > Add `{-# LANGUAGE GeneralizedNewtypeDeriving #-}` to the top of the + > file? (y or n) + + If you answer ‘y‘, it will temporarily jump to the buffer and it to +the top of the file. + +13.7.8 Orphan instances +----------------------- + +If GHC complains about orphan instances, you usually are doing it +intentionally, so it prompts to add ‘-fno-warn-orphans’ to the top of +the file with an ‘OPTIONS’ pragma. + +13.7.9 Auto-adding of dependencies +---------------------------------- + +When doing a build, you will sometimes get a message from GHC like: + + src/ACE/Tokenizer.hs:11:18: Could not find module `Data.Attoparsec.Text' … + It is a member of the hidden package `attoparsec-0.11.1.0'. + + This message contains all the necessary information to add this to +your .cabal file, so you will be prompted to add it to your .cabal file: + + Add `attoparsec' to ace.cabal? (y or n) y + + If you hit ‘y’, it will prompt with this: + + attoparsec >= 0.11.1.0 + + Which you can edit (e.g. do some PVP decision or remove constraints +entirely), and then it will open up your ‘.cabal’ file and go through +each section: + + Add to library? (y or n) y + + This will add it to the top of the ‘build-depends’ field in your +library section. If you have any executables, it will go through each +of those, prompting, too. + + Now you can rebuild with ‘C-c C-c’ again. + +13.8 Haskell Interactive Mode REPL +================================== + +When GHCi has been launched, it works on a read-eval-print basis. So +you will be presented with the prompt: + + The lambdas must flow. + Changed directory: /path/to/your/project/ + λ> + +13.8.1 Changing REPL target +--------------------------- + +With ‘haskell-session-change-target’ you can change the target for REPL +session. + + After REPL session started, in ‘haskell-interactive-mode’ buffer +invoke the ‘haskell-session-change-target’ and select from available +targets for + + - Testing + + - Benchmark + + - Executable + + - Library + + Answer “yes” to restart the session and run your tests, benchmarks, +executables. + + TODO/WRITEME + +13.8.2 Bringing the REPL +------------------------ + +If you don’t know where the REPL buffer is, you can always bring it +with: + + M-x haskell-interactive-bring + + Or ‘C-`’. + +13.8.3 Evaluating expressions +----------------------------- + +To evaluate expressions, simply type one out and hit ‘RET‘. + + λ> 123 + 123 + +13.8.4 Evaluating multiline expressions +--------------------------------------- + +GHCi features two ways to evaluate multiline expressions. You can use +‘:set +m’ to enable multiline input +(https://www.haskell.org/ghc/docs/latest/html/users_guide/ghci.html#multiline-input) +for all expressions, or you can wrap your expression in ‘:{’ and ‘:}’ +(they have to be on their own lines). + + The prompt will change to indicate that you’re inputting a multiline +expression: + + λ> :{ + λ| let a = 10 + λ| b = 20 + λ| c = 30 + λ| :} + + You can also simulate multiline mode by having your input contain +newline characters. You can input a literal newline character with ‘C-q +C-j’, or you can use: + + M-x haskell-interactive-mode-newline-indent + + which is bound to ‘C-j’. This command indents after the newline. +You can simulate the above example like so: + + λ> let a = 10 + b = 20 + c = 30 + +13.8.5 Type of expressions +-------------------------- + +You can use normal ‘:type’ which is part of GHCi to get the type of +something: + + λ> :t id + id :: a -> a + + But you can also just write out the value directly, + + λ> id + id :: a -> a + + and because there’s no ‘Show’ instance for ‘(a -> a)’. This would +normally yield a compile error: + + No instance for (Show (a0 -> a0)) + arising from a use of `print' + Possible fix: add an instance declaration for (Show (a0 -> a0)) + In a stmt of an interactive GHCi command: print it + + It will run ‘:type id’ in the background and print out the result. +The same is true for ambiguous things: + + λ> :t read "a" + read "a" :: Read a => a + + Because this would normally be an ambiguous constraint: + + Ambiguous type variable `a0' in the constraint: + (Read a0) arising from a use of `read' + Probable fix: add a type signature that fixes these type variable(s) + In the expression: read \"a\" + In an equation for `it': it = read \"a\" + + Which is less useful than just printing the type out. + + You can disable this behaviour by disabling the customization option: + + (custom-set-variables + '(haskell-interactive-types-for-show-ambiguous nil)) + +13.8.6 Printing mode +-------------------- + +You can choose between printing modes used for the results of evaluating +expressions. To do that, configure the variable +‘haskell-interactive-mode-eval-mode’. Example: + + (setq haskell-interactive-mode-eval-mode 'haskell-mode) + + A handy function you can use is: + + (defun haskell-interactive-toggle-print-mode () + (interactive) + (setq haskell-interactive-mode-eval-mode + (intern + (ido-completing-read "Eval result mode: " + '("fundamental-mode" + "haskell-mode" + "espresso-mode" + "ghc-core-mode" + "org-mode"))))) + + (Add whichever modes you want to use.) + + And then run + + M-x haskell-interactive-toggle-print-mode + + Or ‘C-c C-v’: + + (define-key haskell-interactive-mode-map (kbd "C-c C-v") + 'haskell-interactive-toggle-print-mode) + + There you can choose ‘haskell-mode‘, for example, to pretty print the +output as Haskell. + +13.8.7 SVG images rendering +--------------------------- + +If you are working on SVG images, you can instruct Emacs to render the +image as the output of an image producing command at the REPL. + + The following example uses the ‘diamgrams’ library with the default +SVG backend to produce a circle: + + {-# LANGUAGE OverloadedStrings #-} + + import Diagrams.Prelude + import Diagrams.Backend.SVG + + myCircle :: Diagram B + myCircle = circle 1 # lc purple # fc yellow + + circle = renderDia SVG (SVGOptions (mkWidth 250) Nothing "" [] True) myCircle + + After enabling SVG rendering with ‘M-x +haskell-svg-toggle-render-images’, if you load the above code and type +‘circle’ at the REPL, you will see the rendered circle instead of the +XML representation of the image. + + This feature can be enabled by default by setting the customization +variable ‘haskell-svg-render-images’ to a non-nil value. + +13.8.8 Presentations +-------------------- + +If you have the ‘present’ package installed, you can use the following +syntax to print anything which is an instance of ‘Data’: + + λ> :present 123 + 123 + + It will print data structures lazily: + + λ> :present [1..] + [1 + ,[Integer]] + + It shows types when there is an unevaluated field in a constructor. +You can click the ‘[Integer]’ or press ‘RET’ on it to expand further: + + λ> :present [1..] + [1 + ,2 + ,[Integer]] + + Etc. Remember: this only works for instances of ‘Data.Data.Data’. + +13.8.9 History +-------------- + +A history is maintained for the duration of the REPL buffer. To go up +and down in the history, run ‘M-p’ for previous and ‘M-n’ for next. + +13.8.10 Cancelling commands +--------------------------- + +To cancel a running REPL command, run ‘C-c C-c’. + +13.8.11 Clear the REPL +---------------------- + +Run ‘C-c C-k’ to clear the REPL. + +13.8.12 Trick: Put Interactive REPL in Separate Frame +----------------------------------------------------- + +The following ‘create-haskell-interactive-frame’ is a quick hack to move +the repl to a separate frame, for those that want a more predictable +layout of windows in Emacs. + + (defun create-unfocused-frame () + (let* + ((prv (window-frame)) + (created (make-frame))) + (select-frame-set-input-focus prv) created)) + + (defun create-haskell-interactive-frame () + (interactive) + (haskell-interactive-bring) + (create-unfocused-frame) + (delete-window)) + + +13.8.13 Troubleshooting +----------------------- + +If the REPL ever goes funny, you can clear the command queue via: + + M-x haskell-process-clear + + Alternatively, you can just restart the process: + + M-x haskell-process-restart + + You can also switch to the buffer ‘*haskell-process-log*’, which can +be enabled and disabled with the customization variable +‘haskell-process-log‘, to see what the cause of your troubles are. + + If the process fails and nothing unusual is in the process log, the +following command can dump the ‘haskell-process’ state: + + M-: (haskell-process) + + The output can be copied from the ‘*Messages*’ buffer. + +13.9 Haskell Interactive Mode Querying +====================================== + +There a few ways GHCi lets you query information about your code. + +13.9.1 Get identifer type +------------------------- + +To print the type of the top-level identifier at point in the REPL and +in the message buffer, run the following command: + + M-x haskell-process-do-type + + or ‘C-c C-t’. + +13.9.2 Insert identifier’s type as type signature +------------------------------------------------- + +To print the type of the top-level identifier at point, run the +following command: + + C-u M-x haskell-process-do-type + + or ‘C-u C-c C-t’. + +13.9.3 Get identifier info +-------------------------- + +To print the info of the identifier at point, run the following command: + + M-x haskell-process-do-info + + or ‘C-c C-i’. + +13.9.4 Presentation mode +------------------------ + +When using ‘C-c C-i’ or ‘C-c C-t’ it will open a buffer in +haskell-presentation-mode. You can hit ‘q’ to close the buffer. + + But you can also continue to use ‘C-c C-i’ inside the buffer to drill +further down data types and classes. + + E.g. if you go to ‘Ord’ in your code buffer and ‘C-c C-i’, it will +popup a buffer containing + + class Eq a => Ord a where + compare :: a -> a -> Ordering + (<) :: a -> a -> Bool + (>=) :: a -> a -> Bool + (>) :: a -> a -> Bool + (<=) :: a -> a -> Bool + max :: a -> a -> a + min :: a -> a -> a + -- Defined in `GHC.Classes' + + And all the instances of that class. But then you can also move your +cursor to ‘Ordering’ and hit ‘C-c C-i’ again to get another popup: + + data Ordering = LT | EQ | GT -- Defined in `GHC.Types' + instance Bounded Ordering -- Defined in `GHC.Enum' + instance Enum Ordering -- Defined in `GHC.Enum' + instance Eq Ordering -- Defined in `GHC.Classes' + instance Ord Ordering -- Defined in `GHC.Classes' + instance Read Ordering -- Defined in `GHC.Read' + instance Show Ordering -- Defined in `GHC.Show' + + And so on. It’s a very good way of exploring a new codebase. + +13.9.5 Browse import’s module +----------------------------- + +To print all exported identifiers of the module imported by the import +line at point, run the following command: + + M-x haskell-process-do-info + + or ‘C-c C-i’. It will print all exports by running ‘:browse +The.Module’ in the GHCi process. + +13.10 Haskell Interactive Mode Cabal integration +================================================ + +There’s some integration with Cabal in Haskell Interactive Mode. Once +you’ve started a session, the features below are available. + +13.10.1 Cabal building +---------------------- + +The most common Cabal action is building, so that has a specific +command: + + M-x haskell-process-cabal-build + + Or ‘C-c C-c’. When building, it will hide unneccessary output. + + For example, to build the ‘ace‘ package, the output is simply: + + Compiling: ACE.Types.Tokens + Compiling: ACE.Combinators + Compiling: ACE.Tokenizer + Compiling: ACE.Parsers + Compiling: ACE.Pretty + Compiling: ACE + Complete: cabal build (0 compiler messages) + + Whereas the complete output is normally: + + Building ace-0.5... + Preprocessing library ace-0.5... + [4 of 9] Compiling ACE.Types.Tokens ( src/ACE/Types/Tokens.hs, dist/build/ACE/Types/Tokens.o ) + [5 of 9] Compiling ACE.Combinators ( src/ACE/Combinators.hs, dist/build/ACE/Combinators.o ) [ACE.Types.Tokens changed] + [6 of 9] Compiling ACE.Tokenizer ( src/ACE/Tokenizer.hs, dist/build/ACE/Tokenizer.o ) [ACE.Types.Tokens changed] + [7 of 9] Compiling ACE.Parsers ( src/ACE/Parsers.hs, dist/build/ACE/Parsers.o ) + [8 of 9] Compiling ACE.Pretty ( src/ACE/Pretty.hs, dist/build/ACE/Pretty.o ) + [9 of 9] Compiling ACE ( src/ACE.hs, dist/build/ACE.o ) [ACE.Tokenizer changed] + In-place registering ace-0.5... + + Which is considerably more verbose but rarely useful or interesting. + +13.10.2 Arbitrary cabal commands +-------------------------------- + +To run an arbitrary Cabal command: + + C-u M-x haskell-process-cabal + + Or run ‘C-u C-c c’. + + It will prompt for an input, so you can write ‘configure -fdev’, for +example. + +13.10.3 Completing cabal commands +--------------------------------- + +To run some common Cabal commands, just run: + + M-x haskell-process-cabal + + Or ‘C-c c’. This is commonly used to do ‘install’, ‘haddock’, +‘configure’, etc. + +13.11 Haskell Interactive Mode Debugger +======================================= + +There is limited support for debugging in GHCi. Haskell Interactive +Mode provides an interface for interacting with this. + +13.11.1 Opening the debug buffer +-------------------------------- + +To open the debug buffer run the following command from any buffer +associated with a session: + + M-x haskell-debug + + It will open a buffer that looks like this: + + Debugging haskell + + You have to load a module to start debugging. + + g - refresh + + Modules + + No loaded modules. + +13.11.2 Loading modules +----------------------- + +To debug anything you need to load something into GHCi. Switch to a +normal file, for example: + + main = do putStrLn "Hello!" + putStrLn "World" + + and load it into GHCi (‘C-c C-l’). Now when you hit ‘g’ (to refresh) +in the debugging buffer, you’ll see something like: + + + Debugging haskell + + b - breakpoint, g - refresh + + Context + + Not debugging right now. + + Breakpoints + + No active breakpoints. + + Modules + + Main - hello.hs + +13.11.3 Setting a breakpoint +---------------------------- + +To set a breakpoint hit ‘b’ in the debugger buffer. It will prompt for +a name. Enter ‘main’ and hit ‘RET’. + + Now the buffer will look like this: + + Debugging haskell + + s - step into an expression, b - breakpoint + d - delete breakpoint, g - refresh + + Context + + Not debugging right now. + + Breakpoints + + 0 - Main (1:8) + + Modules + + Main - hello.hs + +13.11.4 Start stepping +---------------------- + +Hit ‘s’ to step through an expression: it will prompt for an expression +to evaluate and step through. Enter ‘main’ and hit ‘RET’. Now the +buffer will look like this: + + Debugging haskell + + s - step into an expression, b - breakpoint + d - delete breakpoint, a - abandon context, c - continue + p - previous step, n - next step + g - refresh + + Context + + main - hello.hs (stopped) + + do putStrLn "Hello!" + putStrLn "World" + + _result :: IO () = _ + + 1 do putStrLn "Hello!" putStrLn "World" + + Breakpoints + + 0 - Main (1:8) + + Modules + + Main - hello.hs + + What we see here is the current expression being evaluated: + + do putStrLn "Hello!" + putStrLn "World" + + And we see the type of it: + + _result :: IO () = _ + + And we see a backtrace of steps so far: + + 1 do putStrLn "Hello!" putStrLn "World" + +13.11.5 Continue stepping +------------------------- + +To continue stepping, just hit ‘s’ again. Now the context will change +to: + + main - hello.hs (stopped) + + putStrLn "Hello!" + + _result :: IO () = _ + + 1 do putStrLn "Hello!" putStrLn "World" + + Hitting ‘s’ once more, we see the context change to: + + putStrLn "World" + + _result :: IO () = _ + + 2 putStrLn "Hello!" + 1 do putStrLn "Hello!" putStrLn "World" + + Finally hitting ‘s’ again will say "Computation finished". Hitting +‘s’ a final time will change the display back to: + + Debugging haskell + + s - step into an expression, b - breakpoint + d - delete breakpoint, g - refresh + + Context + + Finished debugging. + + 2 putStrLn "Hello!" + 1 do putStrLn "Hello!" putStrLn "World" + + Breakpoints + + 1 - Main (1:8) + + Modules + + Main - hello.hs + + And you’re done debugging. + + +File: haskell-mode.info, Node: Editing Cabal files, Next: Browsing Haddocks, Prev: Interactive Haskell, Up: Top + +14 Editing Cabal files +********************** + +‘haskell-cabal-mode’ is a major mode for editing Cabal package +description files +(http://www.haskell.org/cabal/users-guide/developing-packages.html) and +is automatically associated with files having a ‘.cabal’ extension. + + For quickly locating and jumping to the nearest ‘.cabal’ file from a +Haskell source buffer, you can use ‘M-x haskell-cabal-visit-file’; with +a prefix argument (i.e. ‘C-u’) ‘find-file-other-window’ is used to +visit the ‘.cabal’ file. ‘haskell-cabal-visit-file’ is bound to the key +sequence ‘C-c v c’. + + TODO/WRITEME + + +File: haskell-mode.info, Node: Browsing Haddocks, Next: Spell checking strings and comments, Prev: Editing Cabal files, Up: Top + +15 Browsing Haddocks using ‘w3m’ +******************************** + +An experimental feature is use of the w3m browser to browse Haddock docs +inside Emacs. + +15.1 Get w3m +============ + +Most Linux distributions will have a package for the binary: + + $ sudo apt-get install w3m + + Now grab ‘w3m.el’ from: + + • <http://emacs-w3m.namazu.org/> + • ‘M-x’ ‘package-install’ ‘RET’ ‘w3m’ ‘RET’ + + Confirm installation by trying ‘M-x’ ‘w3m-browse-url’ ‘RET’ +‘haskell.org’ ‘RET’. + + If this works, you’re good to go. + +15.2 Configure w3m +================== + +Now that you have w3m, you probably want to configure it to be more of a +passive viewer than a full-fledged browser. For example: + + (setq w3m-mode-map (make-sparse-keymap)) + + (define-key w3m-mode-map (kbd "RET") 'w3m-view-this-url) + (define-key w3m-mode-map (kbd "q") 'bury-buffer) + (define-key w3m-mode-map (kbd "<mouse-1>") 'w3m-maybe-url) + (define-key w3m-mode-map [f5] 'w3m-reload-this-page) + (define-key w3m-mode-map (kbd "C-c C-d") 'haskell-w3m-open-haddock) + (define-key w3m-mode-map (kbd "M-<left>") 'w3m-view-previous-page) + (define-key w3m-mode-map (kbd "M-<right>") 'w3m-view-next-page) + (define-key w3m-mode-map (kbd "M-.") 'w3m-haddock-find-tag) + + (defun w3m-maybe-url () + (interactive) + (if (or (equal '(w3m-anchor) (get-text-property (point) 'face)) + (equal '(w3m-arrived-anchor) (get-text-property (point) 'face))) + (w3m-view-this-url))) + +15.3 Import w3m-haddock +======================= + +It’s not enabled by default in haskell-mode at present, so you need to +import it manually: + + (require 'w3m-haddock) + +15.4 Add a hook for w3m +======================= + +In order to make haddock pages a little more palatable (and add syntax +highlighting to source view), you can add this hook: + + (add-hook 'w3m-display-hook 'w3m-haddock-display) + + It’s a little rough around the edges, but it’s a start. + +15.5 Configure your package locations +===================================== + +By default, the package locations is set to: + + (defcustom haskell-w3m-haddock-dirs + '("~/.cabal/share/doc/")) + + If you are using an hsenv or a custom package directory, you should +configure this variable with M-x customize-variable or by writing the +custom-set-variables code for it. + +15.6 Finally +============ + +You did all that! Now you’re ready to bind a useful key: + + (define-key haskell-mode-map (kbd "C-c C-d") 'haskell-w3m-open-haddock) + + Now when you press ‘C-c’ ‘C-d’ it will prompt for a package to browse +to. + + This feature will be improved gradually as time goes on. + + +File: haskell-mode.info, Node: Spell checking strings and comments, Next: Aligning code, Prev: Browsing Haddocks, Up: Top + +16 Using with ‘flyspell-prog-mode’ +********************************** + +Strings and comments can be checked for spelling mistakes. There is a +standard Emacs mode for this purpose, ‘flyspell-prog-mode’, that can be +enabled in Haskell buffers. Spelling errors are underlined using +squiggly red lines. + + Documentation for ‘flyspell-prog-mode’ can be found in *Note +(emacs)Spelling::. Here we point to a couple of useful keybindings: + + • ‘M-$’ - Check and correct spelling of the word at point + (‘ispell-word’). + + • ‘digit’ - Replace the word, just this time, with one of the + displayed near-misses. Each near-miss is listed with a digit; type + that digit to select it. + + • ‘SPC’ - Skip this word—continue to consider it incorrect, but don’t + change it here. + + To enable spell checking of strings and comments add this line to +your ‘~/.emacs’ file: + + ‘(add-hook 'haskell-mode-hook 'flyspell-prog-mode)’ + + +File: haskell-mode.info, Node: Aligning code, Next: Rectangular commands, Prev: Spell checking strings and comments, Up: Top + +17 Aligning code +**************** + +Select a region you want to align text within, ‘M-x’ ‘align-regexp’, and +type a regexp representing the alignment delimiter. + + For example, I often line up my Haddock comments: + + f :: a -- ^ does a + -> Foo b -- ^ and b + -> c -- ^ to c + + Select the region, and let the regexp be ‘--’: + + f :: a -- ^ does a + -> Foo b -- ^ and b + -> c -- ^ to c + + Of course, this works for just about anything. Personally, I’ve +globally bound it to ‘C-x a r’: + + (global-set-key (kbd "C-x a r") 'align-regexp) + + Note that you can also just use the rules below for telling the +aligner about Haskell. Once you evaluate this, you can just use ‘M-x’ +‘align’, which I like to bind to ‘M-[’. + + (add-to-list 'align-rules-list + '(haskell-types + (regexp . "\\(\\s-+\\)\\(::\\|∷\\)\\s-+") + (modes quote (haskell-mode literate-haskell-mode)))) + (add-to-list 'align-rules-list + '(haskell-assignment + (regexp . "\\(\\s-+\\)=\\s-+") + (modes quote (haskell-mode literate-haskell-mode)))) + (add-to-list 'align-rules-list + '(haskell-arrows + (regexp . "\\(\\s-+\\)\\(->\\|→\\)\\s-+") + (modes quote (haskell-mode literate-haskell-mode)))) + (add-to-list 'align-rules-list + '(haskell-left-arrows + (regexp . "\\(\\s-+\\)\\(<-\\|←\\)\\s-+") + (modes quote (haskell-mode literate-haskell-mode)))) + + +File: haskell-mode.info, Node: Rectangular commands, Next: REPL, Prev: Aligning code, Up: Top + +18 Using rectangular region commands +************************************ + +Emacs has a set of commands which operate on the region as if it were +rectangular. This turns out to be extremely useful when dealing with +whitespace sensitive languages. + + • ‘C-x r o’ is "Open Rectangle". + + It will shift any text within the rectangle to the right side. + Also see: + + • ‘C-x r t’ is "String Rectangle". + + It will replace any text within the rectangle with the given string + on all the lines in the region. If comment-region didn’t already + exist, you could use this instead, for example. + + • ‘C-x r d’ is "Delete Rectangle". + + It will delete the contents of the rectangle and move anything on + the right over. + + • ‘C-x r r’ is "Copy Rectangle to Register". + + It will prompt you for a register number so it can save it for + later. + + • ‘C-x r g’ is "Insert register". + + This will insert the contents of the given register, overwriting + whatever happens to be within the target rectangle. (So make room) + + • ‘C-x r k’ is "Kill rectangle". + + Delete rectangle and save contents for: + + • ‘C-x r y’ is "Yank rectangle". + + This will insert the contents of the last killed rectangle. + + As with all Emacs modifier combos, you can type ‘C-x r C-h’ to find +out what keys are bound beginning with the ‘C-x r’ prefix. + + +File: haskell-mode.info, Node: REPL, Next: Collapsing Haskell code, Prev: Rectangular commands, Up: Top + +19 Using GHCi REPL within Emacs +******************************* + +To start the REPL you can run one of the following: + + • ‘M-x run-haskell’ + • ‘M-x switch-to-haskell’ + + This repl works with Comint +(https://www.emacswiki.org/emacs/ComintMode). So you will feel at home +if you are already using ‘M-x Shell’ or ‘M-x ielm’. + + ‘Inf-Haskell’ is a Major mode for running GHCi, with comint. + + Important key bindings in ‘Inf-haskell’: + +‘RET’ + invokes ‘comint-send-input’. Sends the input to the GHCi process, + evaluates the line and returns the output. + +‘C-d or <delete>’ + deletes the forward character + +‘<C-up> or M-p’ + invokes ‘comint-previous-input’. Cycle backwards through input + history, saving input. + +‘<C-down> or M-n’ + invokes ‘comint-next-input’. Cycle forwards through input history. + +‘C-c C-c’ + invokes ‘comint-interrupt-subjob’. Sends KeyboardInterrupt signal. + +‘C-c C-\’ + invokes ‘comint-quit-subjob’. Sends KeyboardInterrupt signal. + +‘C-c C-z’ + invokes ‘comint-stop-subjob’. Kills the GHCi process. + +‘C-c M-r’ + invokes ‘comint-previous-matching-input-from-input’. If you are + familiar with ‘C-r’ in bash. This is the same as that. Searches + backwards through input history for match for current input. + +‘C-c M-s’ + invokes ‘comint-next-matching-input-from-input’. Searches forwards + through input history for match for current input. + +‘C-c C-l’ + invokes ‘comint-dynamic-list-input-ring’. Displays a list of + recent inputs entered into the current buffer. + +‘C-c M-o’ + invokes ‘comint-clear-buffer’. Clears the buffer (Only with Emacs + 25.X and above) + +‘C-c C-n’ + invokes ‘comint-next-prompt’. Goes to the start of the previous + REPL prompt. + +‘C-c C-p’ + invokes ‘comint-previous-prompt’. Goes to the start of the next + REPL prompt. + +‘C-c C-o’ + invokes ‘comint-delete-output’. Clears the output of the most + recently evaluated expression. + +‘C-c C-e’ + invokes ‘comint-show-maximum-output’. Moves the point to the end + of the buffer. + +‘C-c C-u’ + invokes ‘comint-kill-input’. Kills backward, the line at point. + (Use this when you have typed in an expression into the prompt but + you dont want to evaluate it.) + +‘C-c C-w’ + invokes ‘backward-kill-word’. Kills backward, the word at point + +‘C-c C-s’ + invokes ‘comint-write-output’. Write output from interpreter since + last input to FILENAME. Any prompt at the end of the output is not + written. + +19.1 Relevant defcustoms: +========================= + +Interpreter (defcustom) Default Possible Values + Value +--------------------------------------------------------------------------- +‘haskell-process-type’ ‘'auto’ ‘'stack-ghci, 'cabal-repl, + 'ghci, 'auto’ +‘inferior-haskell-hook’ ‘nil’ - +‘haskell-process-path-ghci’ ‘ghci’ - +‘haskell-process-args-ghci’ ‘-ferror-spans’- +‘haskell-process-path-cabal’ ‘cabal’ - +‘haskell-process-args-cabal-repl’‘--ghc-option=-ferror-spans’- +‘haskell-process-path-stack’ ‘stack’ - +‘haskell-process-args-stack-ghci’‘--ghci-options=-ferror-spans- + --no-build + --no-load’ + +19.2 More on ‘haskell-process-type’ +=================================== + +The Haskell interpreter used by ‘Inf-Haskell’ is auto-detected by +default, but is customizable with defcustom ‘haskell-process-type’. The +values recognized by it are (default is ’auto): + + • ‘'stack-ghci’ + • ‘'cabal-repl’ + • ‘'ghci’ + • ‘'auto’ + + if the ‘haskell-process-type’ is ‘'auto’, the directories are +searched for ‘cabal.sandbox.config’ or ‘stack.yaml’ or ‘*.cabal’ file. +If the file is present, then appropriate process is started. + + When ‘cabal.sandbox.config’ is found ‘haskell-process-type’ is +‘'cabal-repl’. Similarly, when ‘stack.yaml’ is found +‘haskell-process-type’ is ‘'stack-ghci’. Similarly, when ‘xyz.cabal’ is +found ‘haskell-process-type’ is ‘'cabal-repl’. When nothing is found +‘haskell-process-type’ is ‘'ghci’. When more than one file such as +‘cabal.sandbox.config’ and ‘stack.yaml’ are found the following +preference is followed. + + ‘cabal.sandbox.config’ > ‘stack.yaml’ > ‘*.cabal’ + + +File: haskell-mode.info, Node: Collapsing Haskell code, Next: Getting Help and Reporting Bugs, Prev: REPL, Up: Top + +20 Collapsing Haskell code +************************** + +This is ‘hs-minor-mode’ for ‘haskell-mode’. This module uses hideshow +module. + + To activate this minor mode (haskell-collapse-mode) + • ‘M-x haskell-collapse-mode’ is "To start haskell-collapse-mode". + This minor mode works with indentation. + + In a quick glance: + +‘C-c C-c’ + is bound to ‘haskell-hide-toggle’ +‘C-c C-M-c’ +‘C-c C-M-h’ +‘C-c C-M-s’ + are all bound to ‘haskell-hide-toggle-all’ + + How to use ‘M-x haskell-hide-toggle’? + + Place your point on the code block that you want to collapse and hit +the keybinding. Now the code collapses and you can see the first line +of the block and elipsis. + + Take this example code (example usage of ‘M-x haskell-hide-toggle’): +when you place the cursor here, like this (notice the thick block in the +first line): + + ‘ f█x | rem i 3 == 0 = if i == 0 && (k /= 0) then (c k) else (h j) | +otherwise = 0 where i = sum x j = g x (div i 3) 0 0 [] k = zeroes x 0 ’ + + or + + ‘ f x | rem i 3 == 0 = if i == 0 && (k /= 0) then (c k) else (h j) █ +| otherwise = 0 where i = sum x j = g x (div i 3) 0 0 [] k = zeroes x 0 +’ + + then when you collapse it becomes something like this: + + ‘ f█x... ’ + + It works in terms of (indentation) blocks. + + One more example: + + ‘ f x | rem i 3 == 0 = if i == 0 && (k /= 0) then (c k) else (h j) | +otherwise = 0 w█ere i = sum x j = g x (div i 3) 0 0 [] k = zeroes x 0 ’ + + or + + ‘ f x | rem i 3 == 0 = if i == 0 && (k /= 0) then (c k) else (h j) | +otherwise = 0 where i = sum x j = g x (div i 3) 0 0 [] █ k = zeroes x 0 +’ + + this, will result in something like: + + ‘ f x | rem i 3 == 0 = if i == 0 && (k /= 0) then (c k) else (h j) | +otherwise = 0 where i = sum █... ’ + + The other functionality ‘M-x haskell-hide-toggle-all’ also works only +for indentation and it collapses all toplevel functions. + + So a file that looks like this: + + main = interact $ show.f. map read .words + f (x:xs) = dp x xs + + dp money a | money < 0 || null a = [1..1000] + dp 0 a = [] + dp money a @ (coin:coins) + | (length i) <= length j = i + | otherwise = j + where i = (coin:(dp (money-coin) a)) + j = (dp money coins) + + will turn into this: + + main = interact $ show.f. map read .words + f (x:xs) = dp x xs + + dp money a | money < 0 || null a = [1..1000] + dp 0 a = [] + dp money a @ (coin:coins)... + + +File: haskell-mode.info, Node: Getting Help and Reporting Bugs, Next: Concept index, Prev: Collapsing Haskell code, Up: Top + +21 Getting Help and Reporting Bugs +********************************** + +Work on Haskell Mode is organized with Github ‘haskell-mode’ project. +To understand how the project is run please read the information in the +project wiki pages (https://github.com/haskell/haskell-mode/wiki). + + To report any issues please use the Github’s issue mechanism +available from Haskell Mode’s GitHub Home +(https://github.com/haskell/haskell-mode). + + For a quick question visit ‘#haskell-emacs’ channel on IRC +‘irc.freenode.net’. + + There is also a (now defunct) Haskellmode-emacs mailing list +(http://projects.haskell.org/cgi-bin/mailman/listinfo/haskellmode-emacs), +also available on Gmane (http://gmane.org/) via the +gmane.comp.lang.haskell.emacs +(http://dir.gmane.org/gmane.comp.lang.haskell.emacs) newsgroup. + + We welcome code and non-code contributions so that we can all enjoy +coding Haskell even more. + + +File: haskell-mode.info, Node: Concept index, Next: Function index, Prev: Getting Help and Reporting Bugs, Up: Top + +Concept index +************* + + +* Menu: + +* benchmarking: Interactive Haskell. (line 472) +* CUA mode: Indentation. (line 49) +* customizing: Installation. (line 55) +* customizing <1>: Interactive Haskell. (line 53) +* haskell-mode: Editing Haskell Code. + (line 6) +* Images, rendering SVG images: Interactive Haskell. (line 614) +* indentation: Indentation. (line 6) +* layout rule: Indentation. (line 6) +* off-side rule: Indentation. (line 6) +* rectangle: Indentation. (line 49) +* Rendering SVG images: Interactive Haskell. (line 614) +* SVG images, rendering: Interactive Haskell. (line 614) +* testing: Interactive Haskell. (line 470) +* Unicode: Unicode support. (line 6) + + +File: haskell-mode.info, Node: Function index, Next: Variable index, Prev: Concept index, Up: Top + +Function index +************** + + +* Menu: + +* haskell-cabal-mode: Editing Cabal files. (line 6) +* haskell-cabal-visit-file: Editing Cabal files. (line 11) +* haskell-compile: Compilation. (line 6) +* haskell-decl-scan-mode: Declaration scanning. + (line 6) +* haskell-mode: Editing Haskell Code. + (line 6) +* haskell-session-change-target: Interactive Haskell. (line 463) +* haskell-svg-toggle-render-images: Interactive Haskell. (line 630) + + +File: haskell-mode.info, Node: Variable index, Prev: Function index, Up: Top + +Variable index +************** + + +* Menu: + +* haskell-c2hs-hook-name-face: Syntax highlighting. (line 39) +* haskell-c2hs-hook-pair-face: Syntax highlighting. (line 38) +* haskell-cabal-mode-hook: Editing Cabal files. (line 6) +* haskell-compile-cabal-build-command: Compilation. (line 35) +* haskell-compile-cabal-build-command-alt: Compilation. (line 35) +* haskell-compile-command: Compilation. (line 35) +* haskell-constructor-face: Syntax highlighting. (line 30) +* haskell-decl-scan-mode-hook: Declaration scanning. + (line 6) +* haskell-definition-face: Syntax highlighting. (line 31) +* haskell-interactive-mode-hook: Interactive Haskell. (line 463) +* haskell-keyword-face: Syntax highlighting. (line 28) +* haskell-literate-comment-face: Syntax highlighting. (line 35) +* haskell-mode-hook: Installation. (line 60) +* haskell-operator-face: Syntax highlighting. (line 33) +* haskell-pragma-face: Syntax highlighting. (line 34) +* haskell-process-args-cabal-new-repl: Interactive Haskell. (line 76) +* haskell-process-args-cabal-repl: Interactive Haskell. (line 76) +* haskell-process-args-ghci: Interactive Haskell. (line 76) +* haskell-process-args-stack-ghci: Interactive Haskell. (line 75) +* haskell-process-path-cabal: Interactive Haskell. (line 76) +* haskell-process-path-ghci: Interactive Haskell. (line 76) +* haskell-process-path-stack: Interactive Haskell. (line 76) +* haskell-process-type: Interactive Haskell. (line 76) +* haskell-quasi-quote-face: Syntax highlighting. (line 36) +* haskell-svg-render-images: Interactive Haskell. (line 635) +* haskell-type-face: Syntax highlighting. (line 29) + + + +Tag Table: +Node: Top683 +Node: Introduction2588 +Node: Installation4173 +Node: Editing Haskell Code6796 +Node: Syntax highlighting10556 +Node: Completion support12816 +Node: Unicode support14860 +Node: Indentation19532 +Node: External indentation23008 +Node: Autoformating23736 +Node: Module templates24364 +Node: Declaration scanning24794 +Node: Compilation28082 +Node: Interactive Haskell31987 +Node: Editing Cabal files63864 +Node: Browsing Haddocks64611 +Node: Spell checking strings and comments67436 +Node: Aligning code68542 +Node: Rectangular commands70287 +Node: REPL71807 +Node: Collapsing Haskell code76585 +Node: Getting Help and Reporting Bugs79193 +Node: Concept index80237 +Node: Function index81495 +Node: Variable index82290 + +End Tag Table + + +Local Variables: +coding: utf-8 +End: |