def _nt_alphanumeric_char
start_index = index
if node_cache[:alphanumeric_char].has_key?(index)
cached = node_cache[:alphanumeric_char][index]
@index = cached.interval.end if cached
return cached
end
i0 = index
r1 = _nt_alpha_char
if r1
r0 = r1
else
if input.index(Regexp.new('[0-9]'), index) == index
r2 = instantiate_node(SyntaxNode,input, index...(index + 1))
@index += 1
else
r2 = nil
end
if r2
r0 = r2
else
self.index = i0
r0 = nil
end
end
node_cache[:alphanumeric_char][start_index] = r0
return r0
end