Standardize table and heading markup elements

lib/rdoc/markup.rb

@@ -210,6 +210,7 @@ def convert(input, formatter)
   autoload :BlankLine,             "#{__dir__}/markup/blank_line"
   autoload :BlockQuote,            "#{__dir__}/markup/block_quote"
   autoload :Document,              "#{__dir__}/markup/document"
+  autoload :Element,               "#{__dir__}/markup/element"
   autoload :HardBreak,             "#{__dir__}/markup/hard_break"
   autoload :Heading,               "#{__dir__}/markup/heading"
   autoload :Include,               "#{__dir__}/markup/include"

lib/rdoc/markup/element.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module RDoc
+  class Markup
+    # Base class defining the interface for all markup elements found in documentation
+    # @abstract
+    class Element
+      # @abstract
+      #: (untyped) -> void
+      def accept(visitor)
+        raise NotImplementedError, "#{self.class} must implement the accept method"
+      end
+
+      # @abstract
+      #: (PP) -> void
+      def pretty_print(q)
+        raise NotImplementedError, "#{self.class} must implement the pretty_print method"
+      end
+    end
+  end
+end

lib/rdoc/markup/heading.rb

@@ -1,84 +1,101 @@
 # frozen_string_literal: true
-##
-# A heading with a level (1-6) and text
 
-RDoc::Markup::Heading =
-  Struct.new :level, :text do
-
-  @to_html = nil
-  @to_label = nil
-
-  ##
-  # A singleton RDoc::Markup::ToLabel formatter for headings.
-
-  def self.to_label
-    @to_label ||= RDoc::Markup::ToLabel.new
-  end
-
-  ##
-  # A singleton plain HTML formatter for headings.  Used for creating labels
-  # for the Table of Contents
-
-  def self.to_html
-    return @to_html if @to_html
-
-    markup = RDoc::Markup.new
-    markup.add_regexp_handling RDoc::CrossReference::CROSSREF_REGEXP, :CROSSREF
-
-    @to_html = RDoc::Markup::ToHtml.new nil
-
-    def @to_html.handle_regexp_CROSSREF(target)
-      target.text.sub(/^\\/, '')
+module RDoc
+  class Markup
+    # A heading with a level (1-6) and text
+    #
+    #  RDoc syntax:
+    #   = Heading 1
+    #   == Heading 2
+    #   === Heading 3
+    #
+    #  Markdown syntax:
+    #   # Heading 1
+    #   ## Heading 2
+    #   ### Heading 3
+    class Heading < Element
+      #: String
+      attr_reader :text
+
+      #: Integer
+      attr_accessor :level
+
+      # A singleton RDoc::Markup::ToLabel formatter for headings.
+      #: () -> RDoc::Markup::ToLabel
+      def self.to_label
+        @to_label ||= Markup::ToLabel.new
+      end
+
+      # A singleton plain HTML formatter for headings. Used for creating labels for the Table of Contents
+      #: () -> RDoc::Markup::ToHtml
+      def self.to_html
+        @to_html ||= begin
+          markup = Markup.new
+          markup.add_regexp_handling CrossReference::CROSSREF_REGEXP, :CROSSREF
+
+          to_html = Markup::ToHtml.new nil
+
+          def to_html.handle_regexp_CROSSREF(target)
+            target.text.sub(/^\\/, '')
+          end
+
+          to_html
+        end
+      end
+
+      #: (Integer, String) -> void
+      def initialize(level, text)
+        super()
+
+        @level = level
+        @text = text
+      end
+
+      #: (Object) -> bool
+      def ==(other)
+        other.is_a?(Heading) && other.level == @level && other.text == @text
+      end
+
+      # @override
+      #: (untyped) -> void
+      def accept(visitor)
+        visitor.accept_heading(self)
+      end
+
+      # An HTML-safe anchor reference for this header.
+      #: () -> String
+      def aref
+        "label-#{self.class.to_label.convert text.dup}"
+      end
+
+      # Creates a fully-qualified label which will include the label from +context+. This helps keep ids unique in HTML.
+      #: (RDoc::Context?) -> String
+      def label(context = nil)
+        label = +""
+        label << "#{context.aref}-" if context&.respond_to?(:aref)
+        label << aref
+        label
+      end
+
+      # HTML markup of the text of this label without the surrounding header element.
+      #: () -> String
+      def plain_html
+        no_image_text = text
+
+        if matched = no_image_text.match(/rdoc-image:[^:]+:(.*)/)
+          no_image_text = matched[1]
+        end
+
+        self.class.to_html.to_html(no_image_text)
+      end
+
+      # @override
+      #: (PP) -> void
+      def pretty_print(q)
+        q.group 2, "[head: #{level} ", ']' do
+          q.pp text
+        end
+      end
     end
-
-    @to_html
-  end
-
-  ##
-  # Calls #accept_heading on +visitor+
-
-  def accept(visitor)
-    visitor.accept_heading self
-  end
-
-  ##
-  # An HTML-safe anchor reference for this header.
-
-  def aref
-    "label-#{self.class.to_label.convert text.dup}"
   end
-
-  ##
-  # Creates a fully-qualified label which will include the label from
-  # +context+.  This helps keep ids unique in HTML.
-
-  def label(context = nil)
-    label = aref
-
-    label = [context.aref, label].compact.join '-' if
-      context and context.respond_to? :aref
-
-    label
-  end
-
-  ##
-  # HTML markup of the text of this label without the surrounding header
-  # element.
-
-  def plain_html
-    text = self.text.dup
-
-    if matched = text.match(/rdoc-image:[^:]+:(.*)/)
-      text = matched[1]
-    end
-
-    self.class.to_html.to_html(text)
-  end
-
-  def pretty_print(q) # :nodoc:
-    q.group 2, "[head: #{level} ", ']' do
-      q.pp text
-    end
-  end
-
 end

lib/rdoc/markup/table.rb

@@ -1,52 +1,60 @@
 # frozen_string_literal: true
-##
-# A section of table
 
-class RDoc::Markup::Table
-  # headers of each column
-  attr_accessor :header
+module RDoc
+  class Markup
+    # A section of table
+    class Table < Element
+      # Headers of each column
+      #: Array[String]
+      attr_accessor :header
 
-  # alignments of each column
-  attr_accessor :align
+      # Alignments of each column
+      #: Array[Symbol?]
+      attr_accessor :align
 
-  # body texts of each column
-  attr_accessor :body
+      # Body texts of each column
+      #: Array[String]
+      attr_accessor :body
 
-  # Creates new instance
-  def initialize(header, align, body)
-    @header, @align, @body = header, align, body
-  end
-
-  # :stopdoc:
-  def ==(other)
-    self.class == other.class and
-      @header == other.header and
-      @align == other.align and
-      @body == other.body
-  end
+      #: (Array[String], Array[Symbol?], Array[String]) -> void
+      def initialize(header, align, body)
+        @header, @align, @body = header, align, body
+      end
 
-  def accept(visitor)
-    visitor.accept_table @header, @body, @align
-  end
+      #: (Object) -> bool
+      def ==(other)
+        self.class == other.class && @header == other.header &&
+          @align == other.align && @body == other.body
+      end
 
-  def pretty_print(q)
-    q.group 2, '[Table: ', ']' do
-      q.group 2, '[Head: ', ']' do
-        q.seplist @header.zip(@align) do |text, align|
-          q.pp text
-          if align
-            q.text ":"
-            q.breakable
-            q.text align.to_s
-          end
-        end
+      # @override
+      #: (untyped) -> void
+      def accept(visitor)
+        visitor.accept_table(@header, @body, @align)
       end
-      q.breakable
-      q.group 2, '[Body: ', ']' do
-        q.seplist @body do |body|
-          q.group 2, '[', ']' do
-            q.seplist body do |text|
+
+      # @override
+      #: (untyped) -> String
+      def pretty_print(q)
+        q.group 2, '[Table: ', ']' do
+          q.group 2, '[Head: ', ']' do
+            q.seplist @header.zip(@align) do |text, align|
               q.pp text
+              if align
+                q.text ":"
+                q.breakable
+                q.text align.to_s
+              end
+            end
+          end
+          q.breakable
+          q.group 2, '[Body: ', ']' do
+            q.seplist @body do |body|
+              q.group 2, '[', ']' do
+                q.seplist body do |text|
+                  q.pp text
+                end
+              end
             end
           end
         end