class Parser::Base

def self.default_parser
  parser = new
  parser.diagnostics.all_errors_are_fatal = true
  parser.diagnostics.ignore_warnings      = true
  parser.diagnostics.consumer = lambda do |diagnostic|
    $stderr.puts(diagnostic.render)
  end
  parser
end

def self.parse(string, file='(string)', line=1)
  parser = default_parser
  source_buffer = setup_source_buffer(file, line, string, parser.default_encoding)
  parser.parse(source_buffer)
end

def self.parse_file(filename)
  parse(File.read(filename), filename)
end

def self.parse_file_with_comments(filename)
  parse_with_comments(File.read(filename), filename)
end

def self.parse_with_comments(string, file='(string)', line=1)
  parser = default_parser
  source_buffer = setup_source_buffer(file, line, string, parser.default_encoding)
  parser.parse_with_comments(source_buffer)
end

def self.setup_source_buffer(file, line, string, encoding)
  string = string.dup.force_encoding(encoding)
  source_buffer = Source::Buffer.new(file, line)
  if name == 'Parser::Ruby18'
    source_buffer.raw_source = string
  else
    source_buffer.source     = string
  end
  source_buffer
end

def check_kwarg_name(name_t)
  case name_t[0]
  when /^[a-z_]/
    # OK
  when /^[A-Z]/
    diagnostic :error, :argument_const, name_t
  end
end

def diagnostic(level, kind, location_t, highlights_ts=[])
  _, location = location_t
  highlights = highlights_ts.map do |token|
    _, range = token
    range
  end
  message = ERRORS[kind]
  @diagnostics.process(
      Diagnostic.new(level, message, location, highlights))
  if level == :error
    yyerror
  end
end

def in_def?
  @def_level > 0
end

def initialize(builder=Parser::Builders::Default.new)
  @diagnostics = Diagnostic::Engine.new
  if RUBY_PLATFORM != 'ruby'
    # This is a workaround for a Racc bug. In the pure Ruby Racc runtime,
    # which gets activated on JRuby/RBX, there is a bug in error token
    # popping, which results in an infinite loop.
    @diagnostics.all_errors_are_fatal = true
  end
  @static_env  = StaticEnvironment.new
  @lexer = Lexer.new(version)
  @lexer.diagnostics = @diagnostics
  @lexer.static_env  = @static_env
  @builder = builder
  @builder.parser = self
  if self.class::Racc_debug_parser && ENV['RACC_DEBUG']
    @yydebug = true
  end
  reset
end

def next_token
  @lexer.advance
end

def on_error(error_token_id, error_value, value_stack)
  token_name = token_to_str(error_token_id)
  _, location = error_value
  message = ERRORS[:unexpected_token] % { :token => token_name }
  @diagnostics.process(
      Diagnostic.new(:error, message, location))
end

def parse(source_buffer)
  @lexer.source_buffer = source_buffer
  @source_buffer       = source_buffer
  do_parse
ensure
  # Don't keep references to the source file.
  @source_buffer       = nil
  @lexer.source_buffer = nil
end

def parse_with_comments(source_buffer)
  @lexer.comments = []
  [ parse(source_buffer), @lexer.comments ]
ensure
  @lexer.comments = nil
end

def reset
  @source_buffer = nil
  @def_level     = 0 # count of nested def's.
  @lexer.reset
  @static_env.reset
  self
end

def tokenize(source_buffer)
  @lexer.tokens = []
  ast, comments = parse_with_comments(source_buffer)
  [ ast, comments, @lexer.tokens ]
ensure
  @lexer.tokens = nil
end