history-search-multi-word/hsmw-highlight

# -*- Mode: sh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
# vim:ft=zsh:sw=2:sts=2:et

# -------------------------------------------------------------------------------------------------
# Copyright (c) 2010-2016 zsh-syntax-highlighting contributors
# Copyright (c) 2016-2017 Sebastian Gniazdowski (modifications)
# All rights reserved.
#
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# provided that the following conditions are met:
#
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typeset -gA __hsmw_highlight_main__command_type_cache

# Define default styles.
typeset -gA HSMW_HIGHLIGHT_STYLES
: ${HSMW_HIGHLIGHT_STYLES[default]:=none}
: ${HSMW_HIGHLIGHT_STYLES[unknown-token]:=fg=red,bold}
: ${HSMW_HIGHLIGHT_STYLES[reserved-word]:=fg=yellow}
: ${HSMW_HIGHLIGHT_STYLES[alias]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[suffix-alias]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[builtin]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[function]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[command]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[precommand]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[commandseparator]:=none}
: ${HSMW_HIGHLIGHT_STYLES[hashed-command]:=fg=green}
: ${HSMW_HIGHLIGHT_STYLES[path]:=fg=magenta}
: ${HSMW_HIGHLIGHT_STYLES[path_pathseparator]:=}
: ${HSMW_HIGHLIGHT_STYLES[globbing]:=fg=blue,bold}
: ${HSMW_HIGHLIGHT_STYLES[history-expansion]:=fg=blue,bold}
: ${HSMW_HIGHLIGHT_STYLES[single-hyphen-option]:=fg=cyan}
: ${HSMW_HIGHLIGHT_STYLES[double-hyphen-option]:=fg=cyan}
: ${HSMW_HIGHLIGHT_STYLES[back-quoted-argument]:=none}
: ${HSMW_HIGHLIGHT_STYLES[single-quoted-argument]:=fg=yellow}
: ${HSMW_HIGHLIGHT_STYLES[double-quoted-argument]:=fg=yellow}
: ${HSMW_HIGHLIGHT_STYLES[dollar-quoted-argument]:=fg=yellow}
: ${HSMW_HIGHLIGHT_STYLES[back-or-dollar-double-quoted-argument]:=fg=cyan}
: ${HSMW_HIGHLIGHT_STYLES[back-dollar-quoted-argument]:=fg=cyan}
: ${HSMW_HIGHLIGHT_STYLES[assign]:=none}
: ${HSMW_HIGHLIGHT_STYLES[redirection]:=none}
: ${HSMW_HIGHLIGHT_STYLES[comment]:=fg=black,bold}
: ${HSMW_HIGHLIGHT_STYLES[newline]:=fg=black,bold}  # '\n' strings
: ${HSMW_HIGHLIGHT_STYLES[variable]:=none}


typeset -gA __HSMW_HIGHLIGHT_TOKENS_TYPES

__HSMW_HIGHLIGHT_TOKENS_TYPES=(

  # Precommand

  'builtin'     1
  'command'     1
  'exec'        1
  'nocorrect'   1
  'noglob'      1
  'pkexec'      1 # immune to #121 because it's usually not passed --option flags

  # Control flow
  # Tokens that, at (naively-determined) "command position", are followed by
  # a de jure command position.  All of these are reserved words.

  $'\x7b'   2 # block
  $'\x28'   2 # subshell
  '()'      2 # anonymous function
  'while'   2
  'until'   2
  'if'      2
  'then'    2
  'elif'    2
  'else'    2
  'do'      2
  'time'    2
  'coproc'  2
  '!'       2 # reserved word; unrelated to $histchars[1]

  # Command separators

  '|'   3
  '||'  3
  ';'   3
  '&'   3
  '&&'  3
  '|&'  3
  '&!'  3
  '&|'  3
  # ### 'case' syntax, but followed by a pattern, not by a command
  # ';;' ';&' ';|'
)




# Get the type of a command.
#
# Uses the zsh/parameter module if available to avoid forks, and a
# wrapper around 'type -w' as fallback.
#
# Takes a single argument.
#
# The result will be stored in REPLY.
-hsmw-highlight-main-type() {
  REPLY=$__hsmw_highlight_main__command_type_cache[(e)$1]
  [[ -z "$REPLY" ]] && {

  if zmodload -e zsh/parameter; then
    if (( $+aliases[(e)$1] )); then
      REPLY=alias
    elif (( $+functions[(e)$1] )); then
      REPLY=function
    elif (( $+builtins[(e)$1] )); then
      REPLY=builtin
    elif (( $+commands[(e)$1] )); then
      REPLY=command
    elif (( $+saliases[(e)${1##*.}] )); then
      REPLY='suffix alias'
    elif (( $reswords[(Ie)$1] )); then
      REPLY=reserved
    # zsh 5.2 and older have a bug whereby running 'type -w ./sudo' implicitly
    # runs 'hash ./sudo=/usr/local/bin/./sudo' (assuming /usr/local/bin/sudo
    # exists and is in $PATH).  Avoid triggering the bug, at the expense of
    # falling through to the $() below, incurring a fork.  (Issue #354.)
    #
    # The second disjunct mimics the isrelative() C call from the zsh bug.
    elif [[ $1 != */* || "${+ZSH_ARGZERO}" = "1" ]] && ! builtin type -w -- $1 >/dev/null 2>&1; then
      REPLY=none
    fi
  fi

  [[ -z "$REPLY" ]] && REPLY="${$(LC_ALL=C builtin type -w -- $1 2>/dev/null)##*: }"

  __hsmw_highlight_main__command_type_cache[(e)$1]=$REPLY

  }
}

# Check that the top of $braces_stack has the expected value.  If it does, set
# the style according to $2; otherwise, set style=unknown-token.
#-hsmw-highlight-stack-pop() {

# Below are variables that must be defined in outer
# scope so that they are reachable in *-process()
#
# local right_brace_is_recognised_everywhere
# integer path_dirs_was_set
# integer multi_func_def
# integer ointeractive_comments
-hsmw-highlight-fill-option-variables() {
  if [[ -o ignore_braces ]] || eval '[[ -o ignore_close_braces ]] 2>/dev/null'; then
    right_brace_is_recognised_everywhere=0
  else
    right_brace_is_recognised_everywhere=1
  fi

  if [[ -o path_dirs ]]; then
    path_dirs_was_set=1
  else
    path_dirs_was_set=0
  fi

  if [[ -o multi_func_def ]]; then
    multi_func_def=1
  else
    multi_func_def=0
  fi

  if [[ -o interactive_comments ]]; then
    ointeractive_comments=1
  else
    ointeractive_comments=0
  fi
}

# Main syntax highlighting function.
-hsmw-highlight-process()
{
  emulate -L zsh
  setopt extendedglob bareglobqual nonomatch noksharrays

  (( path_dirs_was_set )) && setopt PATH_DIRS
  (( ointeractive_comments )) && local interactive_comments= # _set_ to empty

  # Variable declarations and initializations
  # in_array_assignment true between 'a=(' and the matching ')'
  # braces_stack: "R" for round, "Q" for square, "Y" for curly
  # mybuf, cdpath_dir are used in sub-functions
  local start_pos="$2" end_pos highlight_glob=1 arg style in_array_assignment=0 MATCH expanded_path braces_stack buf="$1" mybuf cdpath_dir cur_cmd alias_target
  # arg_type can be 0, 1, 2 or 3, i.e. precommand, control flow, command separator
  # idx and end_idx are used in sub-functions
  # for this_word and next_word look below at commented integers and at state machine description
  integer arg_type=0 MBEGIN MEND in_redirection len=${#buf} already_added offset idx end_idx this_word=1 next_word=0 insane_alias
  local -a match mbegin mend

  # integer BIT_start=1 BIT_regular=2 BIT_sudo_opt=4 BIT_sudo_arg=8 BIT_always=16

  # State machine
  #
  # The states are:
  # - :start:      Command word
  # - :sudo_opt:   A leading-dash option to sudo (such as "-u" or "-i")
  # - :sudo_arg:   The argument to a sudo leading-dash option that takes one,
  #                when given as a separate word; i.e., "foo" in "-u foo" (two
  #                words) but not in "-ufoo" (one word).
  # - :regular:    "Not a command word", and command delimiters are permitted.
  #                Mainly used to detect premature termination of commands.
  # - :always:     The word 'always' in the «{ foo } always { bar }» syntax.
  #
  # When the kind of a word is not yet known, $this_word / $next_word may contain
  # multiple states.  For example, after "sudo -i", the next word may be either
  # another --flag or a command name, hence the state would include both :start:
  # and :sudo_opt:.
  #
  # The tokens are always added with both leading and trailing colons to serve as
  # word delimiters (an improvised array); [[ $x == *:foo:* ]] and x=${x//:foo:/} 
  # will DTRT regardless of how many elements or repetitions $x has..
  #
  # Handling of redirections: upon seeing a redirection token, we must stall
  # the current state --- that is, the value of $this_word --- for two iterations
  # (one for the redirection operator, one for the word following it representing
  # the redirection target).  Therefore, we set $in_redirection to 2 upon seeing a
  # redirection operator, decrement it each iteration, and stall the current state
  # when it is non-zero.  Thus, upon reaching the next word (the one that follows
  # the redirection operator and target), $this_word will still contain values
  # appropriate for the word immediately following the word that preceded the
  # redirection operator.
  #
  # The "the previous word was a redirection operator" state is not communicated
  # to the next iteration via $next_word/$this_word as usual, but via
  # $in_redirection.  The value of $next_word from the iteration that processed
  # the operator is discarded.
  #

  # Processing buffer
  local proc_buf="$buf" needle
  for arg in ${interactive_comments-${(z)buf}} \
             ${interactive_comments+${(zZ+c+)buf}}; do
    # Initialize $next_word to its default value?
    (( in_redirection )) && (( --in_redirection ))
    (( in_redirection == 0 )) && next_word=2 # else Stall $next_word.

    # Initialize per-"simple command" [zshmisc(1)] variables:
    #
    #   $already_added       (see next paragraph)
    #   $style               how to highlight $arg
    #   $in_array_assignment boolean flag for "between '(' and ')' of array assignment"
    #   $highlight_glob      boolean flag for "'noglob' is in effect"
    #
    # $already_added is set to 1 to disable adding an entry to region_highlight
    # for this iteration.  Currently, that is done for "" and $'' strings,
    # which add the entry early so escape sequences within the string override
    # the string's color.
    already_added=0
    style=unknown-token
    if (( this_word & 1 )); then
      in_array_assignment=0
      [[ $arg == 'noglob' ]] && highlight_glob=0
    fi

    # Compute the new $start_pos and $end_pos, skipping over whitespace in $buf.
    if [[ $arg == ';' ]] ; then
      # We're looking for either a semicolon or a newline, whichever comes
      # first.  Both of these are rendered as a ";" (SEPER) by the ${(z)..}
      # flag.
      #
      # We can't use the (Z+n+) flag because that elides the end-of-command
      # token altogether, so 'echo foo\necho bar' (two commands) becomes
      # indistinguishable from 'echo foo echo bar' (one command with three
      # words for arguments).
      needle=$'[;\n]'
      offset=$(( ${proc_buf[(i)$needle]} - 1 ))
      (( start_pos += offset ))
      (( end_pos = start_pos + $#arg ))

      # Do not run default code for case when there is a new line
      # It shouldn't be treated as ';', i.e. shouldn't be highlighted
      # as unknown-token when appears after command-starting arg like "{"
      if [[ "${proc_buf[offset+1]}" = $'\n' ]]; then
        (( in_array_assignment )) && (( this_word = 2 )) || { (( this_word = 1 )); highlight_glob=1; }
        in_redirection=0
        reply+=("$(( start_pos - 1)) $end_pos ${HSMW_HIGHLIGHT_STYLES[newline]}")
        proc_buf="${proc_buf[offset + $#arg + 1,len]}"
        start_pos=$end_pos
        continue
      else
        # One more short path – for ';' command separator
        (( in_array_assignment )) && (( this_word = 2 )) || { (( this_word = 1 )); highlight_glob=1; }
        in_redirection=0
        [[ "${HSMW_HIGHLIGHT_STYLES[commandseparator]}" != "none" ]] && reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[commandseparator]}")
        proc_buf="${proc_buf[offset + $#arg + 1,len]}"
        start_pos=$end_pos
        continue
      fi

      arg_type=3
    else
      offset=0
      if [[ "$proc_buf" = (#b)(#s)(([[:space:]]|\\[[:space:]])##)* ]]; then
          # The first, outer parenthesis
          offset="${mend[1]}"
      fi
      ((start_pos+=offset))
      ((end_pos=start_pos+${#arg}))

      # No-hit will result in value 0
      arg_type=${__HSMW_HIGHLIGHT_TOKENS_TYPES[$arg]}
    fi

    proc_buf="${proc_buf[offset + $#arg + 1,len]}"

    # Handle the INTERACTIVE_COMMENTS option.
    #
    # We use the (Z+c+) flag so the entire comment is presented as one token in $arg.
    if [[ -n ${interactive_comments+'set'} && $arg[1] == $histchars[3] ]]; then
      if (( this_word & 3 )); then
        style=comment
      else
        style=unknown-token # prematurely terminated
      fi
      # ADD
      reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[$style]}")
      start_pos=$end_pos
      continue
    fi

    # Analyse the current word.
    if [[ $arg == (<0-9>|)(\<|\>)* ]] && [[ $arg != (\<|\>)$'\x28'* ]]; then
      # A '<' or '>', possibly followed by a digit
      in_redirection=2
    fi

    # Special-case the first word after 'sudo'.
    if (( ! in_redirection )); then
      if (( this_word & 4 )) && [[ $arg != -* ]]; then
        (( this_word = this_word ^ 4 ))
      fi

      # Parse the sudo command line
      if (( this_word & 4 )); then
        case "$arg" in
          # Flag that requires an argument
          '-'[Cgprtu])
                       (( this_word & 1 )) && (( this_word = this_word ^ 1 ))
                       (( next_word = 8 ))
                       ;;
          # This prevents misbehavior with sudo -u -otherargument
          '-'*)
                       (( this_word & 1 )) && (( this_word = this_word ^ 1 ))
                       (( next_word = next_word | 1 ))
                       (( next_word = next_word | 4 ))
                       ;;
          *)           ;;
        esac
      elif (( this_word & 8 )); then
        (( next_word = next_word | 4 ))
        (( next_word = next_word | 1 ))
      fi
   fi

   expanded_path=""

   # The Great Fork: is this a command word?  Is this a non-command word?
   if (( this_word & 16 )) && [[ $arg == 'always' ]]; then
     # try-always construct
     style=reserved-word # de facto a reserved word, although not de jure
     (( next_word = 1 ))
   elif (( this_word & 1 )) && (( in_redirection == 0 )); then # $arg is the command word
     cur_cmd="$arg"
     if (( arg_type == 1 )); then
      style=precommand
     elif [[ "$arg" = "sudo" ]]; then
      style=precommand
      (( next_word & 2 )) && (( next_word = next_word ^ 2 ))
      (( next_word = next_word | 4 ))
      (( next_word = next_word | 1 ))
     else
       # Special-case: command word is '$foo', like that, without braces or anything.
       #
       # That's not entirely correct --- if the parameter's value happens to be a reserved
       # word, the parameter expansion will be highlighted as a reserved word --- but that
       # incorrectness is outweighed by the usability improvement of permitting the use of
       # parameters that refer to commands, functions, and builtins.
       if [[ ${arg[1]} == \$ ]] && (( ${+parameters} )) && [[ ${arg:1} = (#m)([a-zA-Z_][a-zA-Z0-9_]#|[0-9]##) ]] && (( ${+parameters[${MATCH}]} )); then
         -hsmw-highlight-main-type ${(P)MATCH}
       else
         : ${expanded_path::=${(Q)~arg}}
         -hsmw-highlight-main-type $expanded_path
       fi

      case $REPLY in
        reserved)       # reserved word
                        style=reserved-word
                        if [[ $arg == $'\x7b' ]]; then
                          braces_stack='Y'"$braces_stack"
                        elif [[ $arg == $'\x7d' && $braces_stack[1] == "Y" ]]; then
                          # We're at command word, so no need to check $right_brace_is_recognised_everywhere
                          braces_stack[1]=""
                          style=reserved-word
                          (( next_word = next_word | 16 ))
                        fi
                        ;;
        'suffix alias') style=suffix-alias;;
        alias)
                          insane_alias=0
                          case $arg in 
                            # Issue #263: aliases with '=' on their LHS.
                            #
                            # There are three cases:
                            #
                            # - Unsupported, breaks 'alias -L' output, but invokable:
                            ('='*) :;;
                            # - Unsupported, not invokable:
                            (*'='*) insane_alias=1;;
                            # - The common case:
                            (*) :;;
                          esac
                          if (( insane_alias )); then
                            style=unknown-token
                          else
                            style=alias
                            zmodload -e zsh/parameter && alias_target=${aliases[$arg]} || alias_target="${"$(alias -- $arg)"#*=}"
                            [[ ${__HSMW_HIGHLIGHT_TOKENS_TYPES[$alias_target]} = "1" && "$arg_type" != "1" ]] && __HSMW_HIGHLIGHT_TOKENS_TYPES[$arg]="1"
                          fi
                        ;;
        builtin)        style=builtin;;
        function)       style=function;;
        command)        style=command;;
        hashed)         style=hashed-command;;
        none)           # Assign?
                        if [[ $arg == [[:alpha:]_][[:alnum:]_]#(|\[[^\]]#\])(|[+])=* ]] || [[ $arg == [0-9]##(|[+])=* ]]; then
                          style=assign
                          # Assignment to a scalar parameter or to array
                          # (For array assignments, the command doesn't start until the ")" token.)
                          [[ $arg[-1] == '(' ]] && in_array_assignment=1 || (( next_word = next_word | 1 ))
                        elif [[ $arg[1] = $histchars[1] && -n "${arg[2]}" ]]; then
                          style=history-expansion
                        elif [[ $arg[1] == $histchars[2] ]]; then
                          style=history-expansion
                        elif (( arg_type == 3 )); then
                          # This highlights empty commands (semicolon follows nothing) as an error.
                          # Zsh accepts them, though.
                          (( this_word & 2 )) && style=commandseparator
                        elif [[ $arg[1,2] == '((' ]]; then
                          # Arithmetic evaluation.
                          #
                          # Note: prior to zsh-5.1.1-52-g4bed2cf (workers/36669), the ${(z)...}
                          # splitter would only output the '((' token if the matching '))' had
                          # been typed.  Therefore, under those versions of zsh, BUFFER="(( 42"
                          # would be highlighted as an error until the matching "))" are typed.
                          #
                          # We highlight just the opening parentheses, as a reserved word; this
                          # is how [[ ... ]] is highlighted, too.

                          # ADD
                          reply+=("$start_pos $(( start_pos + 2 )) ${HSMW_HIGHLIGHT_STYLES[reserved-word]}")
                          already_added=1
                          # ADD
                          [[ $arg[-2,-1] == '))' ]] && reply+=("$(( end_pos - 2 )) $end_pos ${HSMW_HIGHLIGHT_STYLES[reserved-word]}")
                        elif [[ $arg == '()' ]]; then
                          # anonymous function
                          style=reserved-word
                        elif [[ $arg == $'\x28' ]]; then
                          # subshell
                          style=reserved-word
                          braces_stack='R'"$braces_stack"
                        elif [[ $arg == $'\x29' ]]; then
                          [[ $braces_stack[1] == "R" ]] && { braces_stack[1]=""; style=reserved-word; }
                        elif (( this_word & 14 )); then
                          style=default
                        fi
                        ;;
        *)
                        # ADD
                        # reply+=("$start_pos $end_pos commandtypefromthefuture-$REPLY")
                        already_added=1
                        ;;
      esac
     fi
   # in_redirection || BIT_regular || BIT_sudo_opt || BIT_sudo_arg
   elif (( in_redirection + this_word & 14 ))
   then # $arg is a non-command word
      case $arg in
        ']]')
                 style=reserved-word
                 ;;
        ']')
                 style=builtin
                 ;;
        $'\x29') # subshell or end of array assignment
                 if (( in_array_assignment )); then
                   style=assign
                   in_array_assignment=0
                   (( next_word = next_word | 1 ))
                 elif [[ $braces_stack[1] == "R" ]]; then
                   braces_stack[1]=""
                   style=reserved-word
                 fi;;
        $'\x28\x29') # possibly a function definition
                 # || false # TODO: or if the previous word was a command word
                 (( multi_func_def )) && (( next_word = next_word | 1 ))
                 style=reserved-word
                 # Remove possible annoying unknown-token style, or misleading function style
                 reply[-1]=()
                 ;;
        '--'*)   style=double-hyphen-option;;
        '-'*)    style=single-hyphen-option;;
        "'"*)    style=single-quoted-argument;;
        '"'*)
                 # ADD
                 reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[double-quoted-argument]}")
                 -hsmw-highlight-string
                 already_added=1
                 ;;
        \$\'*)
                 # ADD
                 reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[dollar-quoted-argument]}")
                 -hsmw-highlight-dollar-string
                 already_added=1
                 ;;
        \$[^\(]*)
                 style=variable
                 ;;
        '`'*)    style=back-quoted-argument;;
        [*?]*|*[^\\][*?]*)
                 (( highlight_glob )) && style=globbing || style=default;;
        *)       if [[ $arg = $'\x7d' && $braces_stack[1] == "Y" && "$right_brace_is_recognised_everywhere" = "1" ]]; then
                   # right brace
                   # Parsing rule: # {
                   #
                   #     Additionally, `tt(})' is recognized in any position if neither the
                   #     tt(IGNORE_BRACES) option nor the tt(IGNORE_CLOSE_BRACES) option is set."""
                   braces_stack[1]=""
                   style=reserved-word
                   (( next_word = next_word | 16 ))
                 elif [[ $arg[1] = $histchars[1] && -n "${arg[2]}" ]]; then
                   style=history-expansion
                 elif (( arg_type == 3 )); then
                   style=commandseparator
                 elif (( in_redirection == 2 )); then
                   style=redirection
                 else
                   if (( __hsmw_no_check_paths == 0 )) && -hsmw-highlight-check-path; then
                     # ADD
                     reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[path]}")
                     already_added=1

                     [[ -n "$HSMW_HIGHLIGHT_STYLES[path_pathseparator]" && "$HSMW_HIGHLIGHT_STYLES[path]" != "$HSMW_HIGHLIGHT_STYLES[path_pathseparator]" ]] && {
                       local pos
                       for (( pos = start_pos; pos <= end_pos; pos++ )) ; do
                         # ADD
                         [[ ${buf[pos]} == "/" ]] && reply+=("$(( pos - 1 )) $pos ${HSMW_HIGHLIGHT_STYLES[path_pathseparator]}")
                       done
                     }
                   else
                     style=default
                   fi
                 fi
                 ;;
      esac
    fi

    # ADD
    (( already_added == 0 )) && [[ "${HSMW_HIGHLIGHT_STYLES[$style]}" != "none" ]] && reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[$style]}")

    if (( arg_type == 3 )); then
      if [[ $arg == ';' ]] && (( in_array_assignment )); then
        # literal newline inside an array assignment
        (( next_word = 2 ))
      else
        (( next_word = 1 ))
        highlight_glob=1
      fi
    elif (( arg_type == 1 || arg_type == 2 )) && (( this_word & 1 )); then
         (( next_word = 1 ))
    elif [[ $arg == "repeat" ]] && (( this_word & 1 )); then
      # skip the repeat-count word
      in_redirection=2
      # The redirection mechanism assumes $this_word describes the word
      # following the redirection.  Make it so.
      #
      # That word can be a command word with shortloops (`repeat 2 ls`)
      # or a command separator (`repeat 2; ls` or `repeat 2; do ls; done`).
      #
      # The repeat-count word will be handled like a redirection target.
      (( this_word = 3 ))
    fi
    start_pos=$end_pos
    # This is the default/common codepath.
    (( in_redirection == 0 )) && (( this_word = next_word )) #else # Stall $this_word.
  done
}

# Check if $arg is a path.
# If yes, return 0 and in $REPLY the style to use.
# Else, return non-zero (and the contents of $REPLY is undefined).
-hsmw-highlight-check-path()
{
  : ${expanded_path:=${(Q)~arg}}

  [[ -z $expanded_path ]] && return 1
  [[ -e $expanded_path ]] && return 0

  # Search the path in CDPATH, only for CD command
  [[ "$cur_cmd" = "cd" ]] && for cdpath_dir in $cdpath ; do
    [[ -e "$cdpath_dir/$expanded_path" ]] && return 0
  done

  # It's not a path.
  return 1
}

# Highlight special chars inside double-quoted strings
-hsmw-highlight-string()
{
  mybuf="$arg"
  idx=start_pos

  while [[ "$mybuf" = (#b)[^\$\\]#((\$(#B)([a-zA-Z_:][a-zA-Z0-9_:]#|[0-9]##)(#b)(\[[^\]]#\])(#c0,1))|(\$[{](\([a-zA-Z0@%#]##\))(#c0,1)[a-zA-Z0-9_:#]##(\[[^\]]#\])(#c0,1)[}])|[\\][\'\"\$]|[\\](*))(*) ]]; do
    [[ -n "${match[7]}" ]] && {
      # Skip following char – it is quoted. Choice is
      # made to not highlight such quoting
      idx+=${mbegin[1]}+1
      mybuf="${match[7]:1}"
    } || {
      idx+=${mbegin[1]}-1
      end_idx=idx+${mend[1]}-${mbegin[1]}+1
      mybuf="${match[8]}"

      # ADD
      reply+=("$idx $end_idx ${HSMW_HIGHLIGHT_STYLES[back-or-dollar-double-quoted-argument]}")

      idx=end_idx
    }
  done
}

# Highlight special chars inside dollar-quoted strings
-hsmw-highlight-dollar-string()
{
  local i j k style
  local AA
  integer c
  # Starting dollar-quote is at 1:2, so start parsing at offset 3 in the string.
  for (( i = 3 ; i < end_pos - start_pos ; i += 1 )) ; do
    (( j = i + start_pos - 1 ))
    (( k = j + 1 ))
    case "$arg[$i]" in
      "\\") style=back-dollar-quoted-argument
            for (( c = i + 1 ; c <= end_pos - start_pos ; c += 1 )); do
              [[ "$arg[$c]" != ([0-9xXuUa-fA-F]) ]] && break
            done
            AA=$arg[$i+1,$c-1]
            # Matching for HEX and OCT values like \0xA6, \xA6 or \012
            if [[    "$AA" =~ "^(x|X)[0-9a-fA-F]{1,2}"
                  || "$AA" =~ "^[0-7]{1,3}"
                  || "$AA" =~ "^u[0-9a-fA-F]{1,4}"
                  || "$AA" =~ "^U[0-9a-fA-F]{1,8}"
               ]]; then
              (( k += $#MATCH ))
              (( i += $#MATCH ))
            else
              if (( $#arg > $i+1 )) && [[ $arg[$i+1] == [xXuU] ]]; then
                # \x not followed by hex digits is probably an error
                style=unknown-token
              fi
              (( k += 1 )) # Color following char too.
              (( i += 1 )) # Skip parsing the escaped char.
            fi
            ;;
      *) continue ;;

    esac
    # ADD
    reply+=("$j $k ${HSMW_HIGHLIGHT_STYLES[$style]}")
  done
}

# -------------------------------------------------------------------------------------------------
# Main highlighter initialization
# -------------------------------------------------------------------------------------------------

-hsmw-highlight-init() {
  __hsmw_highlight_main__command_type_cache=()
}

typeset -g __HSMW_MH_SOURCED=1