Class: MarkdownIt::RulesInline::Emphasis

Inherits:
Object
  • Object
show all
Extended by:
Common::Utils
Defined in:
lib/motion-markdown-it/rules_inline/emphasis.rb

Constant Summary

Constants included from Common::Utils

Common::Utils::DIGITAL_ENTITY_TEST_RE, Common::Utils::ENTITY_RE, Common::Utils::HTML_ESCAPE_REPLACE_RE, Common::Utils::HTML_ESCAPE_TEST_RE, Common::Utils::HTML_REPLACEMENTS, Common::Utils::REGEXP_ESCAPE_RE, Common::Utils::UNESCAPE_ALL_RE, Common::Utils::UNESCAPE_MD_RE, Common::Utils::UNICODE_PUNCT_RE

Class Method Summary collapse

Methods included from Common::Utils

arrayReplaceAt, assign, escapeHtml, escapeRE, fromCodePoint, isMdAsciiPunct, isPunctChar, isValidEntityCode, isWhiteSpace, normalizeReference, replaceEntityPattern, unescapeAll, unescapeMd

Class Method Details

.emphasis(state, silent) ⇒ Object 



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# File 'lib/motion-markdown-it/rules_inline/emphasis.rb', line 65

def self.emphasis(state, silent)
  max    = state.posMax
  start  = state.pos
  marker = state.src.charCodeAt(start)

  return false if (marker != 0x5F && marker != 0x2A) #  _ *
  return false if (silent) # don't run any pairs in validation mode

  res = scanDelims(state, start)
  startCount = res[:delims]
  if (!res[:can_open])
    state.pos += startCount
    # Earlier we checked !silent, but this implementation does not need it
    state.pending += state.src.slice(start...state.pos)
    return true
  end

  state.pos = start + startCount
  stack = [ startCount ]

  while (state.pos < max)
    if (state.src.charCodeAt(state.pos) == marker)
      res = scanDelims(state, state.pos)
      count = res[:delims]
      if (res[:can_close])
        oldCount = stack.pop()
        newCount = count

        while (oldCount != newCount)
          if (newCount < oldCount)
            stack.push(oldCount - newCount)
            break
          end

          # assert(newCount > oldCount)
          newCount -= oldCount

          break if (stack.length == 0)
          state.pos += oldCount
          oldCount = stack.pop()
        end

        if (stack.length == 0)
          startCount = oldCount
          found      = true
          break
        end
        state.pos += count
        next
      end

      stack.push(count) if (res[:can_open])
      state.pos += count
      next
    end

    state.md.inline.skipToken(state)
  end

  if (!found)
    # parser failed to find ending tag, so it's not valid emphasis
    state.pos = start
    return false
  end

  # found!
  state.posMax = state.pos
  state.pos    = start + startCount

  # Earlier we checked !silent, but this implementation does not need it

  # we have `startCount` starting and ending markers,
  # now trying to serialize them into tokens
  count = startCount
  while count > 1
    token        = state.push('strong_open', 'strong', 1)
    token.markup = marker.chr + marker.chr
    count -= 2
  end
  if (count % 2 == 1)
    token        = state.push('em_open', 'em', 1)
    token.markup = marker.chr
  end

  state.md.inline.tokenize(state)

  if (count % 2 == 1)
    token        = state.push('em_close', 'em', -1)
    token.markup = marker.chr
  end
  count = startCount
  while count > 1
    token        = state.push('strong_close', 'strong', -1)
    token.markup = marker.chr + marker.chr
    count -= 2
  end

  state.pos     = state.posMax + startCount
  state.posMax  = max
  return true
end

.scanDelims(state, start) ⇒ Object

parse sequence of emphasis markers, “start” should point at a valid marker



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# File 'lib/motion-markdown-it/rules_inline/emphasis.rb', line 11

def self.scanDelims(state, start)
  pos            = start
  left_flanking  = true
  right_flanking = true
  max            = state.posMax
  marker         = state.src.charCodeAt(start)

  # treat beginning of the line as a whitespace
  lastChar = start > 0 ? state.src.charCodeAt(start - 1) : 0x20

  while (pos < max && state.src.charCodeAt(pos) == marker)
    pos += 1
  end

  count = pos - start

  # treat end of the line as a whitespace
  nextChar = pos < max ? state.src.charCodeAt(pos) : 0x20

  isLastPunctChar = isMdAsciiPunct(lastChar) || isPunctChar(lastChar.chr(Encoding::UTF_8))
  isNextPunctChar = isMdAsciiPunct(nextChar) || isPunctChar(nextChar.chr(Encoding::UTF_8))

  isLastWhiteSpace = isWhiteSpace(lastChar)
  isNextWhiteSpace = isWhiteSpace(nextChar)

  if (isNextWhiteSpace)
    left_flanking = false
  elsif (isNextPunctChar)
    if (!(isLastWhiteSpace || isLastPunctChar))
      left_flanking = false
    end
  end

  if (isLastWhiteSpace)
    right_flanking = false
  elsif (isLastPunctChar)
    if (!(isNextWhiteSpace || isNextPunctChar))
      right_flanking = false
    end
  end

  if (marker == 0x5F) # _
    # "_" inside a word can neither open nor close an emphasis
    can_open  = left_flanking  && (!right_flanking || isLastPunctChar)
    can_close = right_flanking && (!left_flanking  || isNextPunctChar)
  else
    can_open  = left_flanking
    can_close = right_flanking
  end

  return { can_open: can_open, can_close: can_close, delims: count }
end