zsh-syntax-highlighting/docs/highlighters.md

zsh-syntax-highlighting / highlighters

Syntax highlighting is done by pluggable highlighters:

• main - the base highlighter, and the only one active by default.
• brackets - matches brackets and parenthesis.
• pattern - matches user-defined patterns.
• cursor - matches the cursor position.
• root - highlights the whole command line if the current user is root.
• line - applied to the whole command line.

How to activate highlighters

To activate an highlighter, add it to the ZSH_HIGHLIGHT_HIGHLIGHTERS array in ~/.zshrc, for example:

ZSH_HIGHLIGHT_HIGHLIGHTERS=(main brackets pattern cursor)

By default, $ZSH_HIGHLIGHT_HIGHLIGHTERS is unset and only the main highlighter is active.

How to tweak highlighters

Highlighters look up styles from the ZSH_HIGHLIGHT_STYLES associative array. Navigate into the individual highlighters' documentation to see what styles (keys) each highlighter defines; the syntax for values is the same as the syntax of "types of highlighting" of the zsh builtin $zle_highlight array, which is documented in the zshzle(1) manual page.

Styles may be set directly or by themes. If no theme is specified in ZSH_HIGHLIGHT_THEME the default theme will be loaded. Additional themes may be layered on top (overriding previous theme's settings) by calling _zsh_highlight_load_theme. _zsh_highlight_load_theme takes either an absolute path to a theme file to load or a theme name. For a theme name the base theme from the themes directory is loaded and then the extensions of the theme that any active highlighter has are loaded. Names must not contain a /.

The default theme is a colorful theme that preserves the defaults the highlighters originally had. The error-only theme is also available for highlighting only syntax errors.

Some highlighters support additional configuration parameters; see each highlighter's documentation for details and examples.

How to implement a new highlighter

To create your own acme highlighter:

• Create your script at highlighters/acme/acme-highlighter.zsh.

• Implement the _zsh_highlight_highlighter_acme_predicate function. This function must return 0 when the highlighter needs to be called and non-zero otherwise, for example:

  _zsh_highlight_highlighter_acme_predicate() {
    # Call this highlighter in SVN working copies
    [[ -d .svn ]]
  }
  

• Implement the _zsh_highlight_highlighter_acme_paint function. This function does the actual syntax highlighting, by calling _zsh_highlight_add_highlight with the start and end of the region to be highlighted and the ZSH_HIGHLIGHT_STYLES key to use. The key should be prefixed with your highlighter name and a colon

  _zsh_highlight_highlighter_acme_paint() { # Colorize the whole buffer with the 'aurora' style _zsh_highlight_add_highlight 0 $#BUFFER acme:aurora }

  
  If you need to test which options the user has set, test `zsyh_user_options`
  with a sensible default if the option is not present in supported zsh
  versions. For example:
  
  ```zsh
  [[ ${zsyh_user_options[ignoreclosebraces]:-off} == on ]]
  

  The option name must be all lowercase with no underscores and not an alias.

• Name your own functions and global variables _zsh_highlight_acme_*.

  • In zsh-syntax-highlighting 0.4.0 and earlier, the entrypoints _zsh_highlight_highlighter_acme_predicate and _zsh_highlight_highlighter_acme_paint were named _zsh_highlight_acme_highlighter_predicate and _zsh_highlight_highlighter_acme_paint respectively.

    These names are still supported for backwards compatibility; however, support for them will be removed in a a future major or minor release (v0.x.0 or v1.0.0).

• Optionally extended the built-in themes in highlighters/${myhighlighter}/themes/${themename}.

  Define the theme's style for that key with ZSH_HIGHLIGHT_STYLES[key]=value, being sure to prefix the key with your highlighter name and a colon. For example:

    ZSH_HIGHLIGHT_STYLES[myhighlighter:aurora]=fg=green
  

• Activate your highlighter in ~/.zshrc:

  ZSH_HIGHLIGHT_HIGHLIGHTERS+=(acme)
  

• Write tests.