diffunitsyntax

Highlight word or character based diff units in diff format

This plugin finds and highlights word or character based changed/added/deleted diff units in a diff format, to make it possible to see the actual differences within a line. This plugin not only works as an additional vim syntax for diff format but also applies the inline diff unit highlighting on some popular git-related plugins.

When a file name extension is .diff or the syntax option is set to diff, a diff file in unified format will be shown like this:

This plugin does:

• identify either of unified, context, or normal "ed" style diff format, which can be provided by some program like diff and git diff commands
• find a pair of corresponding changed lines to be compared in a buffer
• realign them to most similar lines if linematch is set in the diffopt option
• split each line to a list of diff units, based on the DiffUnit buffer-local or global variable
• compare them and find the changed/added/deleted units, using a builtin diff() function or a plugin specific function along with the diffopt option
• highlight those diff units according to syntax, text property, or extended mark mechanism applied on the buffer, using single or several background-colored highlight groups, based on the DiffColors buffer-local or global variable

In addition to those standard diff formats, this plugin identifies a file including git conflict markers and diff indicators (-/+ and </>), and then shows the diff units.

git conflict markers

diff indicators

Diff unit highlighting on other plugins

In some popular git-related plugins, to show git diff output and to preview a diff hunk in normal, preview, and popup/floating windows, another highlighting mechanism such as text property or extended mark is used instead of diff syntax. This plugin applies the inline diff unit highlighting and show actual differences on them, based on the DiffUnitSyntax buffer-local or global variable, on the following plugins (you are welcome to introduce more plugins to support!):

In normal window (when DiffUnitSyntax is set to 1):

vim-fugitive >

neogit >

mini.git >

vim-gin >

In preview and popup/floating windows (when DiffUnitSyntax is set to 2):

gtsigns.nvim >

vim-gitgutter >

vim-signify >

Options

• b:DiffUnit, g:DiffUnit: A type of diff unit

  Value	Description
  'Char'	any single character
  'Word1'	\w\+ word and any \W single character (default)
  'Word2'	non-space and space words
  'Word3'	\< or \> character class boundaries (set by iskeyword option)
  'word'	see word
  'WORD'	see WORD

• b:DiffColors, g:DiffColors: Highlight group for changed units (hl-DiffAdd for added units)

  Value	Description
  0	hl-DiffChange
  1	hl-DiffChange + several highlight groups (default)

• b:DiffUnitSyntax, g:DiffUnitSyntax : Disable this plugin or apply diff unit highlighting

  Value	Description
  0	disable
  1	enable in normal window (default)
  2	enable in normal, preview, and popup/floating windows