module RDoc::Parser::RubyTools

Collection of methods for writing parsers

Public Instance Methods

add_token_listener (obj)

Adds a token listener obj, but you should probably use token_listener

# File lib/rdoc/parser/ruby_tools.rb, line 10
def add_token_listener(obj)
  @token_listeners ||= []
  @token_listeners << obj
end
get_tk ()

Fetches the next token from the scanner

# File lib/rdoc/parser/ruby_tools.rb, line 18
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]
    end
  else
    @read.push @unget_read.shift
    tk = @tokens.shift
  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
get_tk_until (*tokens)

Reads and returns all tokens up to one of tokens. Leaves the matched token in the token list.

# File lib/rdoc/parser/ruby_tools.rb, line 52
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
get_tkread ()

Retrieves a String representation of the read tokens

# File lib/rdoc/parser/ruby_tools.rb, line 73
def get_tkread
  read = @read.join("")
  @read = []
  read
end
peek_read ()

Peek equivalent for get_tkread

# File lib/rdoc/parser/ruby_tools.rb, line 82
def peek_read
  @read.join('')
end
peek_tk ()

Peek at the next token, but don’t remove it from the stream

# File lib/rdoc/parser/ruby_tools.rb, line 89
def peek_tk
  unget_tk(tk = get_tk)
  tk
end
remove_token_listener (obj)

Removes the token listener obj

# File lib/rdoc/parser/ruby_tools.rb, line 97
def remove_token_listener(obj)
  @token_listeners.delete(obj)
end
reset ()

Resets the tools

# File lib/rdoc/parser/ruby_tools.rb, line 104
def reset
  @read       = []
  @tokens     = []
  @unget_read = []
  @nest = 0
  @scanner_point = 0
end
skip_tkspace ()

Skips whitespace tokens including newlines

# File lib/rdoc/parser/ruby_tools.rb, line 115
def skip_tkspace
  tokens = []

  while (tk = get_tk) and (:on_sp == tk[:kind] or :on_nl == tk[:kind] or :on_ignored_nl == tk[:kind]) do
    tokens.push(tk)
  end

  unget_tk(tk)
  tokens
end
skip_tkspace_without_nl ()

Skips whitespace tokens excluding newlines

# File lib/rdoc/parser/ruby_tools.rb, line 129
def skip_tkspace_without_nl
  tokens = []

  while (tk = get_tk) and :on_sp == tk[:kind] do
    tokens.push(tk)
  end

  unget_tk(tk)
  tokens
end
token_listener (obj) { || ... }

Has obj listen to tokens

# File lib/rdoc/parser/ruby_tools.rb, line 143
def token_listener(obj)
  add_token_listener obj
  yield
ensure
  remove_token_listener obj
end
unget_tk (tk)

Returns tk to the scanner

# File lib/rdoc/parser/ruby_tools.rb, line 153
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