module Asciidoctor::Substitutors

def extract_passthroughs text
  compat_mode = @document.compat_mode
  passthrus = @passthroughs
  text = text.gsub InlinePassMacroRx do
    if (boundary = $4) # $$, ++, or +++
      # skip ++ in compat mode, handled as normal quoted text
      next %(#{$2 ? "#{$1}[#{$2}]#{$3}" : "#{$1}#{$3}"}++#{extract_passthroughs $5}++) if compat_mode && boundary == '++'
      if (attrlist = $2)
        if (escape_count = $3.length) > 0
          # NOTE we don't look for nested unconstrained pass macros
          next %(#{$1}[#{attrlist}]#{RS * (escape_count - 1)}#{boundary}#{$5}#{boundary})
        elsif $1 == RS
          preceding = %([#{attrlist}])
        elsif boundary == '++'
          if attrlist == 'x-'
            old_behavior = true
            attributes = {}
          elsif attrlist.end_with? ' x-'
            old_behavior = true
            attributes = parse_quoted_text_attributes attrlist.slice 0, attrlist.length - 3
          else
            attributes = parse_quoted_text_attributes attrlist
          end
        else
          attributes = parse_quoted_text_attributes attrlist
        end
      elsif (escape_count = $3.length) > 0
        # NOTE we don't look for nested unconstrained pass macros
        next %(#{RS * (escape_count - 1)}#{boundary}#{$5}#{boundary})
      end
      subs = (boundary == '+++' ? [] : BASIC_SUBS)
      if attributes
        if old_behavior
          passthrus[passthru_key = passthrus.size] = { text: $5, subs: NORMAL_SUBS, type: :monospaced, attributes: attributes }
        else
          passthrus[passthru_key = passthrus.size] = { text: $5, subs: subs, type: :unquoted, attributes: attributes }
        end
      else
        passthrus[passthru_key = passthrus.size] = { text: $5, subs: subs }
      end
    else # pass:[]
      # NOTE we don't look for nested pass:[] macros
      # honor the escape
      next $&.slice 1, $&.length if $6 == RS
      if (subs = $7)
        passthrus[passthru_key = passthrus.size] = { text: (normalize_text $8, nil, true), subs: (resolve_pass_subs subs) }
      else
        passthrus[passthru_key = passthrus.size] = { text: (normalize_text $8, nil, true) }
      end
    end
    %(#{preceding || ''}#{PASS_START}#{passthru_key}#{PASS_END})
  end if (text.include? '++') || (text.include? '$$') || (text.include? 'ss:')
  pass_inline_char1, pass_inline_char2, pass_inline_rx = InlinePassRx[compat_mode]
  text = text.gsub pass_inline_rx do
    preceding = $1
    attrlist = $4 || $3
    escaped = true if $5
    quoted_text = $6
    format_mark = $7
    content = $8
    if compat_mode
      old_behavior = true
    elsif attrlist && (attrlist == 'x-' || (attrlist.end_with? ' x-'))
      old_behavior = old_behavior_forced = true
    end
    if attrlist
      if escaped
        # honor the escape of the formatting mark
        next %(#{preceding}[#{attrlist}]#{quoted_text.slice 1, quoted_text.length})
      elsif preceding == RS
        # honor the escape of the attributes
        next %(#{preceding}[#{attrlist}]#{quoted_text}) if old_behavior_forced && format_mark == '`'
        preceding = %([#{attrlist}])
      elsif old_behavior_forced
        attributes = attrlist == 'x-' ? {} : (parse_quoted_text_attributes attrlist.slice 0, attrlist.length - 3)
      else
        attributes = parse_quoted_text_attributes attrlist
      end
    elsif escaped
      # honor the escape of the formatting mark
      next %(#{preceding}#{quoted_text.slice 1, quoted_text.length})
    elsif compat_mode && preceding == RS
      next quoted_text
    end
    if compat_mode
      passthrus[passthru_key = passthrus.size] = { text: content, subs: BASIC_SUBS, attributes: attributes, type: :monospaced }
    elsif attributes
      if old_behavior
        subs = format_mark == '`' ? BASIC_SUBS : NORMAL_SUBS
        passthrus[passthru_key = passthrus.size] = { text: content, subs: subs, attributes: attributes, type: :monospaced }
      else
        passthrus[passthru_key = passthrus.size] = { text: content, subs: BASIC_SUBS, attributes: attributes, type: :unquoted }
      end
    else
      passthrus[passthru_key = passthrus.size] = { text: content, subs: BASIC_SUBS }
    end
    %(#{preceding}#{PASS_START}#{passthru_key}#{PASS_END})
  end if (text.include? pass_inline_char1) || (pass_inline_char2 && (text.include? pass_inline_char2))
  # NOTE we need to do the stem in a subsequent step to allow it to be escaped by the former
  text = text.gsub InlineStemMacroRx do
    # honor the escape
    next $&.slice 1, $&.length if $&.start_with? RS
    if (type = $1.to_sym) == :stem
      type = STEM_TYPE_ALIASES[@document.attributes['stem']].to_sym
    end
    subs = $2
    content = normalize_text $3, nil, true
    # NOTE drop enclosing $ signs around latexmath for backwards compatibility with AsciiDoc.py
    content = content.slice 1, content.length - 2 if type == :latexmath && (content.start_with? '$') && (content.end_with? '$')
    subs = subs ? (resolve_pass_subs subs) : ((@document.basebackend? 'html') ? BASIC_SUBS : nil)
    passthrus[passthru_key = passthrus.size] = { text: content, subs: subs, type: type }
    %(#{PASS_START}#{passthru_key}#{PASS_END})
  end if (text.include? ':') && ((text.include? 'stem:') || (text.include? 'math:'))
  text
end