1 files changed, 159 insertions, 0 deletions
diff --git a/lib/rdoc/parser/ruby_tools.rb b/lib/rdoc/parser/ruby_tools.rb
new file mode 100644
index 0000000000..1f621cd32e
--- /dev/null
+++ b/lib/rdoc/parser/ruby_tools.rb
@@ -0,0 +1,159 @@
+# frozen_string_literal: true
+##
+# Collection of methods for writing parsers
+
+module RDoc::Parser::RubyTools
+
+  ##
+  # Adds a token listener +obj+, but you should probably use token_listener
+
+  def add_token_listener(obj)
+    @token_listeners ||= []
+    @token_listeners << obj
+  end
+
+  ##
+  # Fetches the next token from the scanner
+
+  def get_tk
+    tk = nil
+
+    if @tokens.empty? then
+      if @scanner_point >= @scanner.size
+        return nil
+      else
+        tk = @scanner[@scanner_point]
+        @scanner_point += 1
+        @read.push tk[:text]
+        puts "get_tk1 => #{tk.inspect}" if $TOKEN_DEBUG
+      end
+    else
+      @read.push @unget_read.shift
+      tk = @tokens.shift
+      puts "get_tk2 => #{tk.inspect}" if $TOKEN_DEBUG
+    end
+
+    if tk == nil || :on___end__ == tk[:kind]
+      tk = nil
+    end
+
+    return nil unless tk
+
+    # inform any listeners of our shiny new token
+    @token_listeners.each do |obj|
+      obj.add_token(tk)
+    end if @token_listeners
+
+    tk
+  end
+
+  ##
+  # Reads and returns all tokens up to one of +tokens+.  Leaves the matched
+  # token in the token list.
+
+  def get_tk_until(*tokens)
+    read = []
+
+    loop do
+      tk = get_tk
+
+      case tk
+      when *tokens then
+        unget_tk tk
+        break
+      end
+
+      read << tk
+    end
+
+    read
+  end
+
+  ##
+  # Retrieves a String representation of the read tokens
+
+  def get_tkread
+    read = @read.join("")
+    @read = []
+    read
+  end
+
+  ##
+  # Peek equivalent for get_tkread
+
+  def peek_read
+    @read.join('')
+  end
+
+  ##
+  # Peek at the next token, but don't remove it from the stream
+
+  def peek_tk
+    unget_tk(tk = get_tk)
+    tk
+  end
+
+  ##
+  # Removes the token listener +obj+
+
+  def remove_token_listener(obj)
+    @token_listeners.delete(obj)
+  end
+
+  ##
+  # Resets the tools
+
+  def reset
+    @read       = []
+    @tokens     = []
+    @unget_read = []
+    @nest = 0
+    @scanner_point = 0
+  end
+
+  def tk_nl?(tk)
+    :on_nl == tk[:kind] or :on_ignored_nl == tk[:kind]
+  end
+
+  ##
+  # Skips whitespace tokens including newlines if +skip_nl+ is true
+
+  def skip_tkspace(skip_nl = true)
+    tokens = []
+
+    while (tk = get_tk) and (:on_sp == tk[:kind] or (skip_nl and tk_nl?(tk))) do
+      tokens.push(tk)
+    end
+
+    unget_tk(tk)
+    tokens
+  end
+
+  ##
+  # Has +obj+ listen to tokens
+
+  def token_listener(obj)
+    add_token_listener obj
+    yield
+  ensure
+    remove_token_listener obj
+  end
+
+  ##
+  # Returns +tk+ to the scanner
+
+  def unget_tk(tk)
+    @tokens.unshift tk
+    @unget_read.unshift @read.pop
+
+    # Remove this token from any listeners
+    @token_listeners.each do |obj|
+      obj.pop_token
+    end if @token_listeners
+
+    nil
+  end
+
+end
+
+