hsmw-highlight

#!/usr/bin/env zsh
#
# -*- mode: sh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
#
# Copyright (c) 2010-2016 zsh-syntax-highlighting contributors
# Copyright (c) 2016-2017 Sebastian Gniazdowski (modifications)
# Copyright (c) 2021-2022 zdharma-continuum and contributors


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
)

-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
      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)##*: }"

    [[ "$REPLY" = "none" ]] && {
      [[ -d "$1" ]] && REPLY="dirpath" || {
        for cdpath_dir in $cdpath; do
          [[ -d "$cdpath_dir/$1" ]] && { REPLY="dirpath"; break; }
        done
      }
    }

    __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

  # 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.

    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 [[ $arg == ';' ]] ; then
      needle=$'[;\n]'
      offset=$(( ${proc_buf[(i)$needle]} - 1 ))
      (( start_pos += offset ))
      (( end_pos = start_pos + $#arg ))
      if [[ "${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
        (( 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 [[ "$proc_buf" = (#b)(#s)(([[:space:]]|\\[[:space:]])##)* ]]; then
        offset="${mend[1]}"
      fi
      ((start_pos+=offset))
      ((end_pos=start_pos+${#arg}))

      arg_type=${__HSMW_HIGHLIGHT_TOKENS_TYPES[$arg]}
    fi

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

    if [[ -n ${interactive_comments+'set'} && $arg[1] == $histchars[3] ]]; then
      if (( this_word & 3 )); then
        style=comment
      else
        style=unknown-token # prematurely terminated
      fi
      reply+=("$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
        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
              braces_stack[1]=""
              style=reserved-word
              (( next_word = next_word | 16 ))
            elif [[ $arg == "[[" ]]; then
              braces_stack='A'"$braces_stack"
            fi
            ;;
          'suffix alias') style=suffix-alias ;;
          alias)
            insane_alias=0
            case $arg in
              '='*)
                :
                ;;
              *'='*)
                insane_alias=1
                ;;
              *)
                :
                ;;
            esac
            if (( insane_alias )); then
              style=unknown-token
            else
              style=alias
              zmodload -e zsh/parameter && alias_target=${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=() ;;
          command)
            style=command ;;
          hashed)
            style=hashed-command ;;
          dirpath)
            style=path ;;
          none)
            if [[ $arg == [[:alpha:]_][[:alnum:]_]#(|\[[^\]]#\])(|[+])=* ]] || [[ $arg == [0-9]##(|[+])=* ]]; then
              style=assign
              [[ $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_word & 2 )) && style=commandseparator
            elif [[ $arg[1,2] == '((' ]]; then
              reply+=("$start_pos $(( start_pos + 2 )) ${HSMW_HIGHLIGHT_STYLES[reserved-word]}")
              already_added=1
              [[ $arg[-2,-1] == '))' ]] && reply+=("$(( end_pos - 2 )) $end_pos ${HSMW_HIGHLIGHT_STYLES[reserved-word]}")
            elif [[ $arg == '()' ]]; then
              style=reserved-word
            elif [[ $arg == $'\x28' ]]; then
              style=reserved-word
              braces_stack='R'"$braces_stack"
            elif [[ $arg == $'\x29' ]]; then
              [[ $braces_stack[1] == "R" ]] && { braces_stack[1]=""; style=reserved-word; }
            elif (( this_word & 14 )); then
              style=default
            fi
            ;;
          *)
            already_added=1
            ;;
        esac
      fi
    elif (( in_redirection + this_word & 14 )); then
      case $arg in
        ']]')
          style=reserved-word
          [[ $braces_stack[1] == "A" ]] && braces_stack[1]=""
          ;;
        ']')
          style=builtin
          ;;
        $'\x28')
          style=reserved-word
          braces_stack='R'"$braces_stack"
          ;;
        $'\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 ;;
        $'\x28\x29')
          (( multi_func_def )) && (( next_word = next_word | 1 ))
          style=reserved-word
          reply[-1]=()
          ;;
        '--'*)
          style=double-hyphen-option ;;
        '-'*)
          style=single-hyphen-option ;;
        "'"*)
          style=single-quoted-argument ;;
        '"'*)
          reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[double-quoted-argument]}")
          -hsmw-highlight-string
          already_added=1
          ;;
        \$\*)
          reply+=("$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
            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
              reply+=("$start_pos $end_pos ${HSMW_HIGHLIGHT_STYLES[path]}")
              already_added=1


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

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

    if (( arg_type == 3 )); then
      if [[ $arg == ';' ]] && (( in_array_assignment )); then
        (( next_word = 2 ))
      elif [[ -n "${braces_stack[(r)A]}" ]]; then
        (( 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 [[ $arg == "repeat" ]] && (( this_word & 1 )); then
      in_redirection=2
      (( thisword = 3 ))
    fi
    start_pos=$end_pos
    (( in_redirection == 0 )) && (( this_word = next_word ))
  done

  return 0
}

-hsmw-highlight-check-path() {
  : ${expanded_path:=${(Q)~arg}}
  [[ -n "${FAST_BLIST_PATTERNS[(k)$expanded_path]}" ]] && return 1

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

  if [[ "$cur_cmd" = "cd" ]]; then
    for cdpath_dir in $cdpath ; do
      if [[ -e "$cdpath_dir/$expanded_path" ]]; then
        return 0
      fi
    done
  fi

  return 1
}

-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
    if [[ -n "${match[7]}" ]]; then
      idx+=${mbegin[1]}+1
      mybuf="${match[7]:1}"
    else
      idx+=${mbegin[1]}-1
      end_idx=idx+${mend[1]}-${mbegin[1]}+1
      mybuf="${match[8]}"

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

      idx=end_idx
    fi
  done
}

-hsmw-highlight-dollar-string() {
  local i j k style
  local AA
  integer c
  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,$c-1]
        if [[ "$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
            style=unknown-token
          fi
          (( k += 1 )) # Color following char too.
          (( i += 1 )) # Skip parsing the escaped char.
        fi
        ;;
      *)
        continue
        ;;
    esac
    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