FZF `spell` command with dictionary preview

fzf_spell.zsh

# WARNING: depends on `brew install wn`

# Default `fold` to screen width and break at spaces
function fold {
  if [ $# -eq 0 ]; then
    /usr/bin/fold -w $COLUMNS -s
  else
    /usr/bin/fold $*
  fi
}

# Use `fzf` against system dictionary
function spell {
  cat /usr/share/dict/words | fzf --preview 'wn {} -over | fold' --preview-window=up:60%
}