Module: Przn::Parser

Defined in:
lib/przn/parser.rb

Constant Summary collapse

SIZE_SCALES =

Size names → Kitty text sizing scale (1-7)

{
  'xx-small' => 1,
  'x-small'  => 1,
  'small'    => 2,
  'large'    => 3,
  'x-large'  => 4,
  'xx-large' => 5,
  'xxx-large' => 6,
  'xxxx-large' => 7,
  '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5, '6' => 6, '7' => 7
}.freeze
NAMED_COLORS = 
{
  'red' => 31, 'green' => 32, 'yellow' => 33, 'blue' => 34,
  'magenta' => 35, 'cyan' => 36, 'white' => 37,
  'bright_red' => 91, 'bright_green' => 92, 'bright_yellow' => 93,
  'bright_blue' => 94, 'bright_magenta' => 95, 'bright_cyan' => 96,
  'bright_white' => 97
}.freeze
ATTR_RE_SRC =

HTML-ish attribute, three accepted value forms:

key="value"   key='value'   key=bareword

The unquoted token excludes whitespace, ‘=`, `<`, `>`, `“`, `’‘ and backtick, matching the spirit of HTML5’s unquoted-attribute grammar. ‘/` is intentionally NOT excluded so paths like `src=path/to/file` work — which means self-closing tags need a space before `/>` when the last attribute is unquoted (`<img src=foo.png />`).

'\w+=(?:"[^"]*"|\'[^\']*\'|[^\s=<>"\'`]+)'

Class Method Summary collapse

Class Method Details

.normalize_image_attrs!(attrs) ⇒ Object

Rewrite ‘height=“N%”` / `width=“N%”` into the canonical `relative_height=“N”` / `relative_width=“N”` the renderer reads. Values without a `%` suffix pass through unchanged (and are ignored downstream); an explicit `relative_*` already on the block wins so authors can mix forms without surprise.



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# File 'lib/przn/parser.rb', line 302

def normalize_image_attrs!(attrs)
  if (h = attrs['height']) && (m = h.match(/\A(\d+)%\z/))
    attrs.delete('height')
    attrs['relative_height'] ||= m[1]
  end
  if (w = attrs['width']) && (m = w.match(/\A(\d+)%\z/))
    attrs.delete('width')
    attrs['relative_width'] ||= m[1]
  end
end

.parse(markdown) ⇒ Object 



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# File 'lib/przn/parser.rb', line 39

def parse(markdown)
  slides = split_slides(markdown)
  Presentation.new(slides.map { |raw| parse_slide(raw) })
end

.parse_font_attrs(str) ⇒ Object

HTML4-style <font face=“…” size=“…” color=“…”> attributes. Kramdown’s name=“…” legacy spelling for the family is also accepted and folded into :face so the renderer has one shape to handle.



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# File 'lib/przn/parser.rb', line 272

def parse_font_attrs(str)
  attrs = parse_xml_attrs(str)
  attrs[:face] = attrs.delete(:name) if attrs.key?(:name) && !attrs.key?(:face)
  attrs.slice(:face, :size, :color)
end

.parse_image_attrs(str, attrs) ⇒ Object 



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# File 'lib/przn/parser.rb', line 290

def parse_image_attrs(str, attrs)
  str = str.sub(/\A:?\s*/, '')
  str.scan(/([\w-]+)=['"]([^'"]*)['"]/) do |key, value|
    attrs[key.tr('-', '_')] = value
  end
end

.parse_inline(text) ⇒ Object

Parse inline text with Rabbit-compatible markup



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# File 'lib/przn/parser.rb', line 325

def parse_inline(text)
  segments = []
  scanner = StringScanner.new(text)

  until scanner.eos?
    if scanner.scan(/\{::tag\s+name="([^"]+)"\}(.*?)\{:\/tag\}/)
      segments << [:tag, scanner[2], scanner[1]]
    elsif scanner.scan(/<size=([^>\s]+)>(.*?)<\/size>/)
      segments << [:tag, scanner[2], scanner[1]]
    elsif scanner.scan(%r{<font((?:\s+#{ATTR_RE_SRC})+)\s*>(.*?)</font>}o)
      segments << [:font, scanner[2], parse_font_attrs(scanner[1])]
    elsif scanner.scan(%r{\{::font((?:\s+#{ATTR_RE_SRC})+)\}(.*?)\{:/font\}}o)
      segments << [:font, scanner[2], parse_font_attrs(scanner[1])]
    elsif scanner.scan(/\{::note\}(.*?)\{:\/note\}/)
      segments << [:note, scanner[1]]
    elsif scanner.scan(/<note>(.*?)<\/note>/)
      segments << [:note, scanner[1]]
    elsif scanner.scan('{::wait/}') || scanner.scan(/<wait\s*\/>/)
      # skip wait markers in inline text
    elsif scanner.scan('&lt;')
      segments << [:text, '<']
    elsif scanner.scan('&gt;')
      segments << [:text, '>']
    elsif scanner.scan('&amp;')
      segments << [:text, '&']
    elsif scanner.scan(/`([^`]+)`/)
      segments << [:code, scanner[1]]
    elsif scanner.scan(/\*\*(.+?)\*\*/)
      segments << [:bold, scanner[1]]
    elsif scanner.scan(/\*(.+?)\*/)
      segments << [:italic, scanner[1]]
    elsif scanner.scan(/~~(.+?)~~/)
      segments << [:strikethrough, scanner[1]]
    else
      segments << [:text, scanner.scan(/[^`*~{<&]+|./)]
    end
  end

  # Coalesce adjacent :text segments. The scanner has to bail to a
  # single-character `.` when it sees `&` so the `&lt;` / `&gt;` /
  # `&amp;` entity matches can run on the next iteration, which
  # leaves a bare `&` as its own segment and fragments the
  # surrounding text. Merging them back together means one OSC 66
  # multicell sequence per typeset run — important for h1 titles
  # under a proportional font, where Echoes pads each run
  # independently and stray segments become visible gaps.
  segments.each_with_object([]) do |seg, acc|
    if seg[0] == :text && acc.last && acc.last[0] == :text
      acc.last[1] = acc.last[1] + seg[1]
    else
      acc << seg
    end
  end
end

.parse_slide(raw) ⇒ Object 



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# File 'lib/przn/parser.rb', line 65

def parse_slide(raw)
  blocks = []
  lines = raw.lines
  i = 0

  while i < lines.size
    line = lines[i]

    case line
    # {::comment} ... {:/comment} block — skip entirely
    when /\A\s*\{::comment\}/
      i += 1
      i += 1 while i < lines.size && !lines[i].match?(/\{:\/comment\}/)

    # Block alignment: {:.center} or {:.right}
    when /\A\s*\{:\.(\w+)\}\s*\z/
      blocks << {type: :align, align: Regexp.last_match(1).to_sym}

    # Block alignment, XML form: <center>content</center> or <right>content</right>
    when /\A\s*<(center|right)>(.*)<\/\1>\s*\z/
      blocks << {type: :align, align: Regexp.last_match(1).to_sym}
      blocks << {type: :paragraph, content: Regexp.last_match(2)}

    # Slide background (Echoes OSC 7772):
    #   <bg color="#..."/>                              — solid (bg-color)
    #   <bg from="#..." to="#..." angle="N"/>           — linear gradient (bg-gradient)
    # Attribute values may be double-quoted, single-quoted, or
    # unquoted (HTML5-ish — see ATTR_RE_SRC).
    when %r{\A\s*<bg((?:\s+#{ATTR_RE_SRC})*)\s*/>\s*\z}o
      blocks << {type: :bg, attrs: parse_xml_attrs(Regexp.last_match(1))}

    # Absolute-position text:
    #   <at x="N" y="N">content</at>
    #   {::at x="N" y="N"}content{:/at}
    # Content can include inline markup (size, color, font, bold, …).
    when %r{\A\s*<at((?:\s+#{ATTR_RE_SRC})+)\s*>(.*)</at>\s*\z}o
      blocks << {type: :at, attrs: parse_xml_attrs(Regexp.last_match(1)), content: Regexp.last_match(2)}
    when %r{\A\s*\{::at((?:\s+#{ATTR_RE_SRC})+)\}(.*)\{:/at\}\s*\z}o
      blocks << {type: :at, attrs: parse_xml_attrs(Regexp.last_match(1)), content: Regexp.last_match(2)}

    # Fenced code block
    when /\A\s*```(\w*)\s*\z/
      lang = Regexp.last_match(1)
      lang = nil if lang.empty?
      code_lines = []
      i += 1
      while i < lines.size && !lines[i].match?(/\A\s*```\s*\z/)
        code_lines << lines[i]
        i += 1
      end
      # Check for kramdown IAL on next line: {: lang="ruby"}
      if (i + 1) < lines.size && lines[i + 1]&.match?(/\A\s*\{:/)
        i += 1
        if lines[i].match(/lang="(\w+)"/)
          lang = Regexp.last_match(1)
        end
      end
      blocks << {type: :code_block, content: code_lines.join, language: lang}

    # Indented code block (4 spaces)
    when /\A {4}(.*)$/
      code_lines = [Regexp.last_match(1)]
      while (i + 1) < lines.size && lines[i + 1].match?(/\A {4}/)
        i += 1
        code_lines << lines[i].sub(/\A {4}/, '')
      end
      # Check for kramdown IAL: {: lang="ruby"}
      lang = nil
      if (i + 1) < lines.size && lines[i + 1]&.match?(/\A\s*\{:/)
        i += 1
        if lines[i].match(/lang="(\w+)"/)
          lang = Regexp.last_match(1)
        end
      end
      blocks << {type: :code_block, content: code_lines.join("\n") + "\n", language: lang}

    # h1 (slide title)
    when /\A#\s+(.*)/
      blocks << {type: :heading, level: 1, content: Regexp.last_match(1).strip}

    # h2-h6 (sub-headings within slide)
    when /\A(\#{2,6})\s+(.*)/
      level = Regexp.last_match(1).size
      text = Regexp.last_match(2).strip
      blocks << {type: :heading, level: level, content: text}

    # Block quote
    when /\A>\s?(.*)/
      quote_lines = [Regexp.last_match(1)]
      while (i + 1) < lines.size && (m = lines[i + 1].match(/\A>\s?(.*)/))
        i += 1
        quote_lines << m[1]
      end
      blocks << {type: :blockquote, content: quote_lines.join("\n")}

    # Table
    when /\A\|/
      table_lines = [line.strip]
      while (i + 1) < lines.size && lines[i + 1].match?(/\A\|/)
        i += 1
        table_lines << lines[i].strip
      end
      blocks << parse_table(table_lines)

    # Unordered list (* or - item)
    when /\A[*\-]\s+(.*)/
      items = []
      while i < lines.size && (lines[i].match?(/\A[*\-]\s+/) || lines[i].match?(/\A {2,}[*\-]\s+/) || lines[i].match?(/\A {2,}\S/))
        if lines[i].match(/\A(\s*)[*\-]\s+(.*)/)
          depth = Regexp.last_match(1).size / 2
          items << {text: Regexp.last_match(2), depth: depth}
        elsif lines[i].match(/\A {2,}(\S.*)/)
          # Continuation line
          items.last[:text] << ' ' << Regexp.last_match(1) if items.last
        else
          break
        end
        i += 1
      end
      i -= 1
      blocks << {type: :unordered_list, items: items}

    # Ordered list
    when /\A(\s*)\d+\.\s+(.*)/
      items = []
      while i < lines.size && lines[i].match?(/\A\s*\d+\.\s+/)
        lines[i].match(/\A(\s*)\d+\.\s+(.*)/)
        depth = Regexp.last_match(1).size / 3
        items << {text: Regexp.last_match(2), depth: depth}
        i += 1
      end
      i -= 1
      blocks << {type: :ordered_list, items: items}

    # Image, XML form: <img src="path" alt="..." title="..." {:attrs}/>
    # Equivalent to the markdown `![alt](src "title"){:attrs}` form below
    # — emits the same `:image` block so the renderer handles both
    # identically. `src` is required; all other attributes pass through
    # to `block[:attrs]` (string-keyed, matching markdown's IAL parse) so
    # `relative_height`, `width`, etc. work the same way.
    when %r{\A\s*<img((?:\s+#{ATTR_RE_SRC})+)\s*/>\s*\z}o
      raw = parse_xml_attrs(Regexp.last_match(1))
      path = raw.delete(:src)
      if path
        alt = raw.delete(:alt).to_s
        title = raw.delete(:title)
        attrs = raw.transform_keys(&:to_s)
        normalize_image_attrs!(attrs)
        blocks << {type: :image, path: path, alt: alt, title: title, attrs: attrs}
      end

    # Image: ![alt](path "title"){:attrs}
    when /\A!\[([^\]]*)\]\((\S+?)(?:\s+"([^"]*)")?\)(.*)/
      alt = Regexp.last_match(1)
      path = Regexp.last_match(2)
      title = Regexp.last_match(3)
      rest = Regexp.last_match(4).strip
      attrs = {}
      if rest.match(/\{([^}]+)\}/)
        parse_image_attrs(Regexp.last_match(1), attrs)
      elsif rest.match(/\{(.+)/) || ((i + 1) < lines.size && lines[i + 1]&.match?(/\A\s*\{/))
        attr_str = rest.sub(/\A\{:?\s*/, '')
        while !attr_str.include?('}') && (i + 1) < lines.size
          i += 1
          attr_str << ' ' << lines[i].strip
        end
        attr_str = attr_str.sub(/\}\s*\z/, '')
        parse_image_attrs(attr_str, attrs)
      end
      normalize_image_attrs!(attrs)
      blocks << {type: :image, path: path, alt: alt, title: title, attrs: attrs}

    # Definition list: term on one line, :   definition on next
    when /\A(\S.*)\s*\z/
      if (i + 1) < lines.size && lines[i + 1].match?(/\A:\s{3}/)
        term = Regexp.last_match(1).strip
        i += 1
        definition_lines = []
        while i < lines.size && lines[i].match?(/\A:\s{3}(.*)|\A {4}(.*)/)
          if lines[i].match(/\A:\s{3}(.*)/)
            definition_lines << Regexp.last_match(1)
          elsif lines[i].match(/\A {4}(.*)/)
            definition_lines << Regexp.last_match(1)
          end
          i += 1
        end
        i -= 1
        blocks << {type: :definition_list, term: term, definition: definition_lines.join("\n")}
      else
        blocks << {type: :paragraph, content: Regexp.last_match(1).strip}
      end

    when /\A\s*\z/
      blocks << {type: :blank}

    else
      blocks << {type: :paragraph, content: line.strip}
    end
    i += 1
  end

  Slide.new(blocks)
end

.parse_table(lines) ⇒ Object 



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# File 'lib/przn/parser.rb', line 313

def parse_table(lines)
  rows = []
  lines.each do |line|
    next if line.match?(/\A\|[-|:\s]+\|\s*\z/)  # separator row

    cells = line.split('|').map(&:strip).reject(&:empty?)
    rows << cells
  end
  {type: :table, header: rows.first, rows: rows.drop(1)}
end

.parse_xml_attrs(str) ⇒ Object

Generic attribute scanner — three value forms accepted:

key="value"   key='value'   key=bareword

Returns a hash with symbolized keys. Doesn’t validate which keys are allowed; callers slice.



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# File 'lib/przn/parser.rb', line 282

def parse_xml_attrs(str)
  attrs = {}
  str.scan(/(\w+)=(?:"([^"]*)"|'([^']*)'|([^\s=<>"'`]+))/) do |key, dq, sq, uq|
    attrs[key.to_sym] = dq || sq || uq
  end
  attrs
end

.split_slides(markdown) ⇒ Object

Split on h1 headings (Rabbit-compatible)



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# File 'lib/przn/parser.rb', line 45

def split_slides(markdown)
  chunks = []
  current = +''
  in_fence = false

  markdown.each_line do |line|
    if line.match?(/\A\s*```/)
      in_fence = !in_fence
      current << line
    elsif !in_fence && line.match?(/\A#\s/)
      chunks << current unless current.strip.empty?
      current = +line
    else
      current << line
    end
  end
  chunks << current unless current.strip.empty?
  chunks
end