def _nt_white
start_index = index
if node_cache[:white].has_key?(index)
cached = node_cache[:white][index]
if cached
node_cache[:white][index] = cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
@index = cached.interval.end
end
return cached
end
if has_terminal?(@regexps[gr = '\A[ \\t\\n\\r]'] ||= Regexp.new(gr), :regexp, index)
r0 = instantiate_node(SyntaxNode,input, index...(index + 1))
@index += 1
else
terminal_parse_failure('[ \\t\\n\\r]')
r0 = nil
end
node_cache[:white][start_index] = r0
r0
end