Vim

Table of contents

My vim config

My vim config and other dotfiles can be found here: https://github.com/benjaminheng/dotfiles/tree/master/nvim/.config/nvim

`:cdo` and `:cfdo`

:cdo executes a command on each entry in the quickfix list, whereas :cfdo executes a command for each file in the quickfix list.

This can be useful for refactoring if you have a way to quickly populate entries in the quickfix list. Since I use fzf.vim, I normally do so with :Ag.

As an example, let’s say we have the following lines in a number of different files:

// foo.go
func DoThingX() {}

// bar.go
func bar() {
    DoThingX()
}

// baz.go
func baz() {
    DoThingX()
}

Using :Ag DoThingX and selecting the results we put the following into our quickfix list:

bar.go|4 col 2| DoThingX()
baz.go|4 col 2| DoThingX()
foo.go|9 col 6| func DoThingX() {}

If we wanted to rename DoThingX to DoThingY across these files, we can do so using :cdo s/DoThingX/DoThingY/ | update.

Other resources: Vim’s new :cdo command.

`\zs` and `\ze`

\zs and \ze are regex patterns that allow matching a substring of a total regex match. \zs indicates the start of the match, and \ze the end.

This is useful when matching against a long string, but you only want to replace a substring of it. For instance given the following piece of code:

func DoThingX() error {}

func foo() {
    err := DoThingX()
}

We change DoThingX to return two values (v string, err error), and we want to update the callsites with the new function signature. err := DoThingX() needs to be changed to _, err := DoThingX().

Without \zs and \ze we might do something like :s/err := DoThingX/_, err := DoThingX/.

With \zs and \ze we can instead match a substring within the full regex match, and replace only the substring. We can do :s/\zs\zeerr := DoThingX/_, /g.

Breaking it down, we’re still matching against err := DoThingX, but the \zs\ze at the beginning indicates where our replacement will be applied. In this case, our replacement is inserted at the beginning of the match.

Execute a macro in buffers using `:bufdo` or `:argdo`

:bufdo executes a macro in all open buffers. :argdo executes a macro in all files in the arglist (:args).

:bufdo execute "normal! @a" | update
:argdo execute "normal! @a" | update

Syntax highlighting for Go text template tags in HTML files

If vim-go is installed, it comes with syntax highlighting files for the gohtmltmpl filetype. Enable using:

:set ft=gohtmltmpl

Alternatively, if you don’t want to install vim-go, you can also copy the gohtmltmpl.vim files from vim-go’s repository. Some modification to the files may be needed.

Syntax highlighting for code blocks in markdown files

By default vim uses tpope’s Markdown runtime files for syntax highlighting. Enable syntax highlighting in code blocks using:

let g:markdown_fenced_languages = ['html', 'python', 'bash=sh']

Syntax highlighting for YAML frontmatter in Markdown files

Add the following to after/syntax/markdown.vim.

unlet b:current_syntax
syntax include @Yaml syntax/yaml.vim
syntax region yamlFrontmatter start=/\%^---$/ end=/^---$/ keepend contains=@Yaml

Read from stdin into a new, unsaved named file

Opens vim with some content in the buffer. The file is named, but not yet saved to disk.

echo "some content" | nvim - -c "file /tmp/filename.txt"

Edit macro contents

Use C-r followed by a register to paste the contents of the register.

:let @a=<C-r>a

When used in insert mode, the contents is pasted into the buffer. In insert mode, it’s recommended to use C-r twice to paste literally, otherwise the text is treated as though typed and is subject to autoindent and other formatting options.

Update buffer from external command, keeping cursor position

I haven’t tested the actual command yet, this is just a demonstration of winsaveview, winrestview, and keepjumps.

function Format() {
    let s:save = winsaveview()
    silent keepjumps execute !goimports -w %
    call winrestview(s:save)
}

Common errors

Tab key not working in insert mode with UltiSnips, neovim

Make sure the python3 binary is properly referenced:

let g:python_host_prog='/usr/bin/python'
let g:python3_host_prog='/Users/benheng/.pyenv/shims/python3'

ALE lint markers not appearing in Go files

Patch the following handler to detect go vet output:

diff --git a/autoload/ale/handlers/go.vim b/autoload/ale/handlers/go.vim
index f17cd862..cada0890 100644
--- a/autoload/ale/handlers/go.vim
+++ b/autoload/ale/handlers/go.vim
@@ -8,7 +8,8 @@
 " Description: moved to generic Golang file from govet

 function! ale#handlers#go#Handler(buffer, lines) abort
-    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):?(\d+)?:? ?(.+)$'
+    let l:pattern = '\v^%(vet:\s*)?([a-zA-Z]?:?[^:]+):(\d+):?(\d+)?:? ?(.+)$'
     let l:output = []
     let l:dir = expand('#' . a:buffer . ':p:h')

NERDTree panel does not resize

Issue: https://github.com/preservim/nerdtree/issues/1321

As a workaround, apply the patch:

diff --git a/lib/nerdtree/menu_controller.vim b/lib/nerdtree/menu_controller.vim
index 952c67b..df34d66 100644
--- a/lib/nerdtree/menu_controller.vim
+++ b/lib/nerdtree/menu_controller.vim
@@ -172,6 +172,7 @@ endfunction
 function! s:MenuController._restoreOptions()
     let &cmdheight = self._oldCmdheight
     let &lazyredraw = self._oldLazyredraw
+    resize
 endfunction
 
 "FUNCTION: MenuController._cursorDown() {{{1

Neovim’s LSP omnifunc does not support fuzzy matches

Issue: https://github.com/neovim/neovim/issues/15414

This is currently blocking me from adopting neovim’s built-in LSP. The LSP server provides fuzzy matching, but the omnifunc handler is filtering them out.

[vim-go] Outdated tags when switching branches or generating code

This can occur when you have an existing vim session, and you either switch branches, generate code, or otherwise change the state of the codebase from an external source. The tags can become outdated, and omnicompletion does not pick up the new tags. One way to solve this is to simply restart vim to reinitialize gopls. Alternatively the following command can be used (stackoverflow comment):

:GoBuildTags ''

Vim