def _nt_addr_spec
start_index = index
if node_cache[:addr_spec].has_key?(index)
cached = node_cache[:addr_spec][index]
@index = cached.interval.end if cached
return cached
end
i0 = index
i1, s1 = index, []
r2 = _nt_local_part
s1 << r2
if r2
if has_terminal?("@", false, index)
r3 = instantiate_node(SyntaxNode,input, index...(index + 1))
@index += 1
else
terminal_parse_failure("@")
r3 = nil
end
s1 << r3
if r3
r4 = _nt_domain
s1 << r4
end
end
if s1.last
r1 = instantiate_node(SyntaxNode,input, i1...index, s1)
r1.extend(AddrSpec0)
else
@index = i1
r1 = nil
end
if r1
r0 = r1
else
r5 = _nt_local_part
if r5
r0 = r5
else
@index = i0
r0 = nil
end
end
node_cache[:addr_spec][start_index] = r0
r0
end