[vim] add plugin for golang

1 files changed, 250 insertions, 0 deletions

diff --git a/vim/ftplugin/go/import.vim b/vim/ftplugin/go/import.vim
new file mode 100644
index 0000000..91c8697
--- /dev/null
+++ b/vim/ftplugin/go/import.vim
@@ -0,0 +1,250 @@
+" Copyright 2011 The Go Authors. All rights reserved.
+" Use of this source code is governed by a BSD-style
+" license that can be found in the LICENSE file.
+"
+" import.vim: Vim commands to import/drop Go packages.
+"
+" This filetype plugin adds three new commands for go buffers:
+"
+"   :Import {path}
+"
+"       Import ensures that the provided package {path} is imported
+"       in the current Go buffer, using proper style and ordering.
+"       If {path} is already being imported, an error will be
+"       displayed and the buffer will be untouched.
+"
+"   :ImportAs {localname} {path}
+"
+"       Same as Import, but uses a custom local name for the package.
+"
+"   :Drop {path}
+"
+"       Remove the import line for the provided package {path}, if
+"       present in the current Go buffer.  If {path} is not being
+"       imported, an error will be displayed and the buffer will be
+"       untouched.
+"
+" If you would like to add shortcuts, you can do so by doing the following:
+"
+"   Import fmt
+"   au Filetype go nnoremap <buffer> <LocalLeader>f :Import fmt<CR>
+"
+"   Drop fmt
+"   au Filetype go nnoremap <buffer> <LocalLeader>F :Drop fmt<CR>
+"
+"   Import the word under your cursor
+"   au Filetype go nnoremap <buffer> <LocalLeader>k
+"       \ :exe 'Import ' . expand('<cword>')<CR>
+"
+" The backslash '\' is the default maplocalleader, so it is possible that
+" your vim is set to use a different character (:help maplocalleader).
+"
+" Options:
+"
+"   g:go_import_commands [default=1]
+"
+"       Flag to indicate whether to enable the commands listed above.
+"
+if exists("b:did_ftplugin_go_import")
+    finish
+endif
+
+if !exists("g:go_import_commands")
+    let g:go_import_commands = 1
+endif
+
+if g:go_import_commands
+    command! -buffer -nargs=? -complete=customlist,go#complete#Package Drop call s:SwitchImport(0, '', <f-args>)
+    command! -buffer -nargs=1 -complete=customlist,go#complete#Package Import call s:SwitchImport(1, '', <f-args>)
+    command! -buffer -nargs=* -complete=customlist,go#complete#Package ImportAs call s:SwitchImport(1, <f-args>)
+endif
+
+function! s:SwitchImport(enabled, localname, path)
+    let view = winsaveview()
+    let path = a:path
+
+    " Quotes are not necessary, so remove them if provided.
+    if path[0] == '"'
+        let path = strpart(path, 1)
+    endif
+    if path[len(path)-1] == '"'
+        let path = strpart(path, 0, len(path) - 1)
+    endif
+    if path == ''
+        call s:Error('Import path not provided')
+        return
+    endif
+
+    " Extract any site prefix (e.g. github.com/).
+    " If other imports with the same prefix are grouped separately,
+    " we will add this new import with them.
+    " Only up to and including the first slash is used.
+    let siteprefix = matchstr(path, "^[^/]*/")
+
+    let qpath = '"' . path . '"'
+    if a:localname != ''
+        let qlocalpath = a:localname . ' ' . qpath
+    else
+        let qlocalpath = qpath
+    endif
+    let indentstr = 0
+    let packageline = -1 " Position of package name statement
+    let appendline = -1  " Position to introduce new import
+    let deleteline = -1  " Position of line with existing import
+    let linesdelta = 0   " Lines added/removed
+
+    " Find proper place to add/remove import.
+    let line = 0
+    while line <= line('$')
+        let linestr = getline(line)
+
+        if linestr =~# '^package\s'
+            let packageline = line
+            let appendline = line
+
+        elseif linestr =~# '^import\s\+('
+            let appendstr = qlocalpath
+            let indentstr = 1
+            let appendline = line
+            let firstblank = -1
+            let lastprefix = ""
+            while line <= line("$")
+                let line = line + 1
+                let linestr = getline(line)
+                let m = matchlist(getline(line), '^\()\|\(\s\+\)\(\S*\s*\)"\(.\+\)"\)')
+                if empty(m)
+                    if siteprefix == "" && a:enabled
+                        " must be in the first group
+                        break
+                    endif
+                    " record this position, but keep looking
+                    if firstblank < 0
+                        let firstblank = line
+                    endif
+                    continue
+                endif
+                if m[1] == ')'
+                    " if there's no match, add it to the first group
+                    if appendline < 0 && firstblank >= 0
+                        let appendline = firstblank
+                    endif
+                    break
+                endif
+                let lastprefix = matchstr(m[4], "^[^/]*/")
+                if a:localname != '' && m[3] != ''
+                    let qlocalpath = printf('%-' . (len(m[3])-1) . 's %s', a:localname, qpath)
+                endif
+                let appendstr = m[2] . qlocalpath
+                let indentstr = 0
+                if m[4] == path
+                    let appendline = -1
+                    let deleteline = line
+                    break
+                elseif m[4] < path
+                    " don't set candidate position if we have a site prefix,
+                    " we've passed a blank line, and this doesn't share the same
+                    " site prefix.
+                    if siteprefix == "" || firstblank < 0 || match(m[4], "^" . siteprefix) >= 0
+                        let appendline = line
+                    endif
+                elseif siteprefix != "" && match(m[4], "^" . siteprefix) >= 0
+                    " first entry of site group
+                    let appendline = line - 1
+                    break
+                endif
+            endwhile
+            break
+
+        elseif linestr =~# '^import '
+            if appendline == packageline
+                let appendstr = 'import ' . qlocalpath
+                let appendline = line - 1
+            endif
+            let m = matchlist(linestr, '^import\(\s\+\)\(\S*\s*\)"\(.\+\)"')
+            if !empty(m)
+                if m[3] == path
+                    let appendline = -1
+                    let deleteline = line
+                    break
+                endif
+                if m[3] < path
+                    let appendline = line
+                endif
+                if a:localname != '' && m[2] != ''
+                    let qlocalpath = printf("%s %" . len(m[2])-1 . "s", a:localname, qpath)
+                endif
+                let appendstr = 'import' . m[1] . qlocalpath
+            endif
+
+        elseif linestr =~# '^\(var\|const\|type\|func\)\>'
+            break
+
+        endif
+        let line = line + 1
+    endwhile
+
+    " Append or remove the package import, as requested.
+    if a:enabled
+        if deleteline != -1
+            call s:Error(qpath . ' already being imported')
+        elseif appendline == -1
+            call s:Error('No package line found')
+        else
+            if appendline == packageline
+                call append(appendline + 0, '')
+                call append(appendline + 1, 'import (')
+                call append(appendline + 2, ')')
+                let appendline += 2
+                let linesdelta += 3
+                let appendstr = qlocalpath
+                let indentstr = 1
+            endif
+            call append(appendline, appendstr)
+            execute appendline + 1
+            if indentstr
+                execute 'normal >>'
+            endif
+            let linesdelta += 1
+        endif
+    else
+        if deleteline == -1
+            call s:Error(qpath . ' not being imported')
+        else
+            execute deleteline . 'd'
+            let linesdelta -= 1
+
+            if getline(deleteline-1) =~# '^import\s\+(' && getline(deleteline) =~# '^)'
+                " Delete empty import block
+                let deleteline -= 1
+                execute deleteline . "d"
+                execute deleteline . "d"
+                let linesdelta -= 2
+            endif
+
+            if getline(deleteline) == '' && getline(deleteline - 1) == ''
+                " Delete spacing for removed line too.
+                execute deleteline . "d"
+                let linesdelta -= 1
+            endif
+        endif
+    endif
+
+    " Adjust view for any changes.
+    let view.lnum += linesdelta
+    let view.topline += linesdelta
+    if view.topline < 0
+        let view.topline = 0
+    endif
+
+    " Put buffer back where it was.
+    call winrestview(view)
+
+endfunction
+
+function! s:Error(s)
+    echohl Error | echo a:s | echohl None
+endfunction
+
+let b:did_ftplugin_go_import = 1
+
+" vim:ts=4:sw=4:et