haskellmode.txt Haskell Mode Plugins 02/05/2009
Authors: Claus Reinke claus.reinke@talk21.com ~
Homepage: http://projects.haskell.org/haskellmode-vim
CONTENTS haskellmode
1. Overview |haskellmode-overview|
1.1 Runtime Requirements |haskellmode-requirements|
1.2 Quick Reference |haskellmode-quickref|
2. Settings |haskellmode-settings|
2.1 GHC and web browser |haskellmode-settings-main|
2.2 Fine tuning - more configuration options |haskellmode-settings-fine|
3. GHC Compiler Integration |haskellmode-compiler|
4. Haddock Integration |haskellmode-haddock|
4.1 Indexing |haskellmode-indexing|
4.2 Lookup |haskellmode-lookup|
4.3 Editing |haskellmode-editing|
5. Hpaste Integration |haskellmode-hpaste|
6. Additional Resources |haskellmode-resources|============================================================================== haskellmode-overview
Overview ~
The Haskell mode plugins provide advanced support for Haskell development using GHC/GHCi on Windows and Unix-like systems. The functionality is based on Haddock-generated library indices, on GHCi's interactive commands, or on simply activating (some of) Vim's built-in program editing support in Haskell-relevant fashion. These plugins live side-by-side with the pre-defined |syntax-highlighting| support for |haskell| sources, and any other Haskell-related plugins you might want to install (see |haskellmode-resources|).
The Haskell mode plugins consist of three filetype plugins (haskell.vim, haskell_doc.vim, haskell_hpaste.vim), which by Vim's |filetype| detection mechanism will be auto-loaded whenever files with the extension '.hs' are opened, and one compiler plugin (ghc.vim) which you will need to load from your vimrc file (see |haskellmode-settings|).
*haskellmode-requirements*1.1 Runtime Requirements ~
The plugins require a recent installation of GHC/GHCi. The functionality derived from Haddock-generated library indices also requires a local installation of the Haddock documentation for GHC's libraries (if there is no documentation package for your system, you can download a tar-ball from haskell.org), as well as an HTML browser (see |haddock_browser|). If you want to use the experimental hpaste interface, you will also need Wget.
GHC/GHCi ~ Provides core functionality. http://www.haskell.org/ghc
HTML library documentation files and indices generated by Haddock ~ These usually come with your GHC installation, possibly as a separate package. If you cannot get them this way, you can download a tar-ball matching your GHC version from http://www.haskell.org/ghc/docs/
HTML browser with basic CSS support ~ For browsing Haddock docs.
Wget ~ For interfacing with http://hpaste.org.
Wget is widely available for modern Unix-like operating systems. Several ports also exist for Windows, including:
Official GNU Wget (natively compiled for Win32) http://www.gnu.org/software/wget/#downloading
UnxUtils Wget (natively compiled for Win32, bundled with other ported Unix utilities) http://sourceforge.net/projects/unxutils/
Cygwin Wget (emulated POSIX in Win32, must be run under Cygwin) http://cygwin.com/packages/wget/
*haskellmode-quickref*1.2 Quick Reference ~
|:make| load into GHCi, show errors (|quickfix| |:copen|)
|_ct| create |tags| file
|_si| show info for id under cursor
|_t| show type for id under cursor
|T| insert type declaration for id under cursor
|balloon| show type for id under mouse pointer
|?| browse Haddock entry for id under cursor
|?1| search Hoogle for id under cursor
|?2| search Hayoo! for id under cursor
|:IDoc| {identifier} browse Haddock entry for unqualified {identifier}
|:MDoc| {module} browse Haddock entry for {module}
|:FlagReference| {s} browse Users Guide Flag Reference for section {s}
|_.| qualify unqualified id under cursor
|_i| add 'import
|:GHCStaticOptions| edit static GHC options for this buffer |:DocSettings| show current Haddock-files-related plugin settings |:DocIndex| populate Haddock index |:ExportDocIndex| cache current Haddock index to a file |:HpasteIndex| Read index of most recent entries from hpaste.org |:HpastePostNew| Submit current buffer as a new hpaste
============================================================================== haskellmode-settings
Settings ~
The plugins try to find their dependencies in standard locations, so if you're lucky, you will only need to set |compiler| to ghc, and configure the location of your favourite web browser. You will also want to make sure that |filetype| detection and |syntax| highlighting are on. Given the variety of things to guess, however, some dependencies might not be found correctly, or the defaults might not be to your liking, in which case you can do some more fine tuning. All of this configuration should happen in your |vimrc|.
" enable syntax highlighting syntax on
" enable filetype detection and plugin loading
filetype plugin on<
*haskellmode-settings-main*2.1 GHC and web browser ~
*compiler-ghc* *ghc-compiler*To use the features provided by the GHC |compiler| plugin, use the following |autocommand| in your vimrc:
au BufEnter .hs compiler ghc < g:ghc* If the compiler plugin can't locate your GHC binary, or if you have several versions of GHC installed and have a preference as to which binary is used, set |g:ghc|:
:let g:ghc="/usr/bin/ghc-6.6.1" < g:haddock_browser The preferred HTML browser for viewing Haddock documentation can be set as follows:
:let g:haddock_browser="/usr/bin/firefox" <
*haskellmode-settings-fine*2.2 Fine tuning - more configuration options ~
Most of the fine tuning is likely to happen for the haskellmode_doc.vim plugin, so you can check the current settings for this plugin via the command |:DocSettings|. If all the settings reported there are to your liking, you probably won't need to do any fine tuning.
*g:haddock_browser_callformat*By default, the web browser|g:haddock_browser| will be started asynchronously (in the background) on Windows or when vim is running in a GUI, and synchronously (in the foreground) otherwise. These settings seem to work fine if you are using a console mode browser (eg, when editing in a remote session), or if you are starting a GUI browser that will launch itself in the background. But if these settings do not work for you, you can change the default browser launching behavior.
This is controlled by |g:haddock_browser_callformat|. It specifies a format string which uses two '%s' parameters, the first representing the path of the browser to launch, and the second is the documentation URL (minus the protocol specifier, i.e. file://) passed to it by the Haddock plugin. For instance, to launch a GUI browser on Unix-like systems and force it to the background (see also |shellredir|):
:let g:haddock_browser_callformat = '%s file://%s '.printf(&shellredir,'/dev/null').' &' < g:haddock_browser_nosilent
If you find that on your system opening the documentation browser corrupts the vim display, you can choose to not exec the browser silently. This often fixes the display but means you have to press a key to continue after opening the browser.
:let g:haddock_browser_nosilent = 1 < g:haddock_docdir
Your system's installed Haddock documentation for GHC and its libraries should be automatically detected. If the plugin can't locate them, you must point |g:haddock_docdir| to the path containing the master index.html file for the subdirectories 'libraries', 'Cabal', 'users_guide', etc.:
:let g:haddock_docdir="/usr/local/share/doc/ghc/html/" < g:haddock_indexfiledir The information gathered from Haddock's index files will be stored in a file called 'haddock_index.vim' in a directory derived from the Haddock location, or in $HOME. To configure another directory for the index file, use:
:let g:haddock_indexfiledir="~/.vim/" < g:wget If you also want to try the experimental hpaste functionality, you might need to set |g:wget| before the |hpaste| plugin is loaded (unless wget is in your PATH):
:let g:wget="C:\Program Files\wget\wget.exe" <
Another experimental functionality is caching the symbol information to a background file. If you are importing big modules such as OpenGL, loading the symbol information from GHCi by |:GHCReload| can take really long time. To shorten the time it takes to browse the symbols you can enable caching of the symbol data to a background file every time |:GHCReload| is called. When browsing for a symbol, if the symbol table is empty and cached file is available, it is used to populate the symbol table. To enable the symbol cache set the following variable to 1:
:let g:ghc_symbolcache=1 <
Finally, the mappings actually use|
============================================================================== haskellmode-compiler ghc
GHC Compiler Integration ~
The GHC |compiler| plugin sets the basic |errorformat| and |makeprg| to enable |quickfix| mode using GHCi, and provides functionality for show info (|_si|), show type (|_t| or mouse |balloon|), add type declaration (|_T|), create tag file (|_ct|), and insert-mode completion (|i_CTRL-X_CTRL-O|) based on GHCi browsing of the current and imported modules.
To avoid frequent calls to GHCi, type information is cached in Vim. The cache will be populated the first time a command depends on it, and will be refreshed every time a |:make| goes through without generating errors (if the |:make| does not succeed, the old types will remain available in Vim). You can also unconditionally force reloading of type info using |:GHCReload| (if GHCi cannot load your file, the type info will be empty).
In addition to the standard|quickfix| commands, the GHC compiler plugin provides:
*:GHCReload*:GHCReload Reload modules and unconditionally refresh cache of type info. Usually, |:make| is prefered, as that will refresh the cache only if GHCi reports no errors, and show the errors otherwise.
*:GHCStaticOptions*:GHCStaticOptions Edit the static GHC options (more generally, options that cannot be set by in-file OPTIONS_GHC pragmas) for the current buffer. Useful for adding hidden packages (-package ghc), or additional import paths (-isrc; you will then also want to augment |path|). If you have static options you want to set as defaults, you could use b:ghc_staticoptions, eg:
au FileType haskell let b:ghc_staticoptions = '-isrc' au FileType haskell setlocal path += src <
*:GHCi*:GHCi {command/expr} Run GHCi commands/expressions in the current module.
*_ct*_ct Create |tags| file for the current Haskell source file. This uses GHCi's :ctags command, so it will work recursively, but will only list tags for exported entities.
*_opt*_opt Shows a menu of frequently used GHC compiler options (selecting an entry adds the option as a pragma to the start of the file). Uses popup menu (GUI) or :emenu and command-line completion (CLI).
*_lang*_lang Shows a menu of the LANGUAGE options supported by GHC (selecting an entry adds the language as a pragma to the start of the file). Uses popup menu (GUI) or :emenu and command-line completion (CLI).
*_si*_si Show extended information for the name under the cursor. Uses GHCi's :info command. Output appears in |preview-window| (when done, close with |:pclose|).
*_t*_t Show type for the name under the cursor. Uses cached info from GHCi's :browse command.
*_T*_T Insert type declaration for the name under the cursor. Uses cached info from GHCi's :browse command.
*haskellmode-XO* *haskellmode-omni-completion*CTRL-X CTRL-O Standard insert-mode omni-completion based on the cached type info from GHCi browsing current and imported modules. Only names from the current and from imported modules are included (the completion menu also show the type of each identifier).
============================================================================== haskellmode-haddock haddock
Haddock Integration ~
Haskell mode integrates with Haddock-generated HTML documentation, providing features such as navigating to the Haddock entry for the identifier under the cursor (|_?|), completion for the identifier under the cursor (|i_CTRL-X_CTRL-U|), and adding import statements (|_i| |_im| |_iq| |iqm|) or module qualifier (|.|) for the identifier under the cursor.
These commands operate on an internal Haddock index built from the platform's installed Haddock documentation for GHC's libraries. Since populating this index takes several seconds, it should be stored as a file called 'haddock_index.vim' in the directory specified by |g:haddock_indexfiledir|.
Some commands present a different interface (popup menu or command-line completion) according to whether the current Vim instance is graphical or console-based (actually: whether or not the GUI is running). Such differences are marked below with the annotations (GUI) and (CLI), respectively.
|:DocSettings| shows the settings for this plugin. If you are happy with them, you can call |:ExportDocIndex| to populate and write out the documentation index (should be called once for every new version of GHC).
*:DocSettings*:DocSettings Show current Haddock-files-related plugin settings.
*haskellmode-indexing*4.1 Indexing ~
*:DocIndex*:DocIndex Populate the Haddock index from the GHC library documentation.
*:ExportDocIndex*:ExportDocIndex Cache the current Haddock index to a file (populate index first, if empty).
*haskellmode-lookup*4.2 Lookup ~
*_?*_? Open the Haddock entry (in |haddock_browser|) for an identifier under the cursor, selecting full qualifications from a popup menu (GUI) or via command-line completion (CLI), if the identifier is not qualified.
*_?1*_?1 Search Hoogle (using |haddock_browser|) for an identifier under the cursor.
*_?2*_?2 Search Hayoo! (using |haddock_browser|) for an identifier under the cursor.
*:IDoc*:IDoc {identifier} Open the Haddock entry for the unqualified {identifier} in |haddock_browser|, suggesting possible full qualifications.
*:MDoc*:MDoc {module} Open the Haddock entry for {module} in |haddock_browser| (with command-line completion for the fully qualified module name).
*:FlagReference*:FlagReference {s} Browse Users Guide Flag Reference for section {s} (with command-line completion for section headers).
*haskellmode-editing*4.3 Editing ~
*_.*_. Fully qualify the unqualified name under the cursor selecting full qualifications from a popup menu (GUI) or via command-line completion (CLI).
*_iq* *_i*_i _iq Add 'import [qualified]
*_iqm* *_im*_im Add 'import [qualified]
*_ie*_ie On an 'import
*haskellmode-XU* *haskellmode-user-completion*CTRL-X CTRL-U User-defined insert mode name completion based on all names known to the Haddock index, including package names. Completions are presented in a popup menu which also displays the fully qualified module from which each entry may be imported.
CamelCode shortcuts are supported, meaning that
lower-case letters can be elided, using only
upper-case letters and module qualifier separators (.)
for disambiguation:
pSL -> putStrLn
C.E.t -> Control.Exception.t
C.M.MP -> Control.Monad.MonadPlus
To reduce unwanted matches, the first letter of such
shortcuts and the first letter after each '.' have to
match directly.============================================================================== haskellmode-hpaste hpaste
Hpaste Integration ~
This experimental feature allows browsing and posting to http://hpaste.org, a Web-based pastebin tailored for Haskell code.
*:HpasteIndex*:HpasteIndex Read the most recent entries from hpaste.org. Show an index of the entries in a new buffer, where ',r' will open the current highlighted entry [and ',p' will annotate it with the current buffer].
*:HpastePostNew*:HpastePostNew Submit current buffer as a new hpaste entry. [This, and ',p' above, are temporarily disabled, needs update to new hpaste.org layout]
============================================================================== haskellmode-resources
Additional Resources ~
An quick screencast tour through of these plugins is available at:
http://projects.haskell.org/haskellmode-vim/screencasts.html
Other Haskell-related Vim plugins can be found here:
http://www.haskell.org/haskellwiki/Libraries_and_tools/Program_development#Vim
Make sure to read about Vim's other program-editing features in its online |user-manual|. Also have a look at Vim tips and plugins at www.vim.org - two other plugins I tend to use when editing Haskell are AlignPlugin.vim (to line up regexps for definitions, keywords, comments, etc. in consecutive lines) and surround.vim (to surround text with quotes, brackets, parentheses, comments, etc.).
============================================================================== vim:tw=78:ts=8:ft=help: