def _nt_group
start_index = index
if node_cache[:group].has_key?(index)
cached = node_cache[:group][index]
@index = cached.interval.end if cached
return cached
end
i0, s0 = index, []
r1 = _nt_display_name
s0 << r1
if r1
if has_terminal?(":", false, index)
r2 = instantiate_node(SyntaxNode,input, index...(index + 1))
@index += 1
else
terminal_parse_failure(":")
r2 = nil
end
s0 << r2
if r2
i4 = index
r5 = _nt_mailbox_list_group
if r5
r4 = r5
else
r6 = _nt_CFWS
if r6
r4 = r6
else
@index = i4
r4 = nil
end
end
if r4
r3 = r4
else
r3 = instantiate_node(SyntaxNode,input, index...index)
end
s0 << r3
if r3
if has_terminal?(";", false, index)
r7 = instantiate_node(SyntaxNode,input, index...(index + 1))
@index += 1
else
terminal_parse_failure(";")
r7 = nil
end
s0 << r7
if r7
r9 = _nt_CFWS
if r9
r8 = r9
else
r8 = instantiate_node(SyntaxNode,input, index...index)
end
s0 << r8
end
end
end
end
if s0.last
r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
r0.extend(Group0)
else
@index = i0
r0 = nil
end
node_cache[:group][start_index] = r0
r0
end