*haskellmode.txt*	Haskell Mode Plugins	02/05/2009

Authors:
    Claus Reinke <[email protected]> ~

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*
1. 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 <module>(<identifier>)' for id under cursor
|_im|                 add 'import <module>' for id under cursor
|_iq|                 add 'import qualified <module>(<identifier>)' for id under cursor
|_iqm|                add 'import qualified <module>' for id under cursor
|_ie|                 make imports explit for import statement under cursor
|_opt|                add OPTIONS_GHC pragma
|_lang|               add LANGUAGE pragma
|i_CTRL-X_CTRL-O|     insert-mode completion based on imported ids (|haskellmode-XO|)
|i_CTRL-X_CTRL-U|     insert-mode completion based on documented ids (|haskellmode-XU|)
|i_CTRL-N|            insert-mode completion based on imported sources
|:GHCi|{command/expr} run GHCi command/expr in current module

|: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*
2. 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|<LocalLeader>|behind the scenes, so if
    you have to, you can redefine|maplocalleader|to something other than '_'.
    Just remember that the docs still refer to mappings starting with '_', to
    avoid confusing the majority of users!-)

==============================================================================
                                                  *haskellmode-compiler* *ghc*
3. 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*
4. 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] <module>(<identifier>)'
                        statement for the identifier under the cursor,
                        selecting fully qualified modules from a popup menu
                        (GUI) or via command-line completion (CLI), if the
                        identifier is not qualified.  This currently adds one
                        import statement per call instead of merging into
                        existing import statements.

                                                                  *_iqm* *_im*
_im                     Add 'import [qualified] <module>' statement for the
                        identifier under the cursor, selecting fully qualified
                        modules from a popup menu (GUI) or via command-line
                        completion (CLI), if the identifier is not qualified.
                        This currently adds one import statement per call
                        instead of merging into existing import statements.

                                                                         *_ie*
_ie                     On an 'import <module>' line, in a correctly loadable
                        module, temporarily comment out import and use :make
                        'not in scope' errors to explicitly list imported
                        identifiers.

                                *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*
5. 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*
6. 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: