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.

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

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

• Implement the _zsh_highlight_acme_highlighter 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. Define the default style for that key in the highlighter script outside of any function with : ${ZSH_HIGHLIGHT_STYLES[key]:=value}, being sure to prefix the key with your highlighter name and a colon. For example:

    : ${ZSH_HIGHLIGHT_STYLES[acme:aurora]:=fg=green}
  
    _zsh_highlight_acme_highlighter() {
      # Colorize the whole buffer with the 'aurora' style
      _zsh_highlight_add_highlight 0 $#BUFFER acme:aurora
    }
  

• Activate your highlighter in ~/.zshrc:

    ZSH_HIGHLIGHT_HIGHLIGHTERS+=(acme)
  

• Write tests.