prezto/themes/minimal/prompt_minimal_setup

function +vi-git-status() {
  # Untracked files.
  if [[ -n $(git ls-files --other --exclude-standard 2> /dev/null) ]]; then
    hook_com[unstaged]='%F{red}●%f'
  fi
}

function prompt_minimal_precmd () {
  setopt NO_XTRACE NO_KSHARRAYS LOCAL_OPTIONS
  vcs_info
}

function prompt_minimal_setup() {
  setopt NO_XTRACE NO_KSHARRAYS LOCAL_OPTIONS
  prompt_opts=(cr subst percent)

  autoload -Uz add-zsh-hook
  autoload -Uz vcs_info

  add-zsh-hook precmd prompt_minimal_precmd

  zstyle ':vcs_info:*' enable bzr git hg svn
  zstyle ':vcs_info:*' check-for-changes true
  zstyle ':vcs_info:*' stagedstr '%F{green}●%f'
  zstyle ':vcs_info:*' unstagedstr '%F{yellow}●%f'
  zstyle ':vcs_info:*' formats ' - [%b%c%u]'
  zstyle ':vcs_info:*' actionformats " - [%b%c%u|%F{cyan}%a%f]"
  zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b|%F{cyan}%r%f'
  zstyle ':vcs_info:git*+set-message:*' hooks git-status

  PROMPT='%2~${vcs_info_msg_0_} » '
}

prompt_minimal_setup "$@"