anchor.diff:  %%
   %% The .proto file is expected to be found in a directories specified by an
   %% `{i,directory()}' option. It is possible to specify `{i,directory()}'
  -%% several times, they will be search in the order specified.
  +%% several times, they will be searched in the order specified.
   %%
   %% The `{type_specs,boolean()}' option enables or disables `::Type()'
   %% annotations in the generated .hrl file. Default is currently
  
positive.code: %% in which case they will be proplists instead. This option is not
  %% compatible with the `nif' option.
  %%
  %% The `nif' option will cause the compiler to generate code which
  %% decoding code is nif C++ code. The generated can be linked with the
  %% Google protobuf C++ library.  Read the file `README.nif-cc' for
  %% more info. This option is not compatible with the `maps' option;
  %% the generated C++ decoding code would still create records.
  %%
  %% The `binary' option will cause the generated and compiled code be
  %% returned as a binary. No files will be written. The return value
  %% will be on the form `{ok,Mod,Code}' or `{ok,Mod,Code,Warnings}'
  %% if the compilation is succesful. This option may be useful
  
negative.code: %% messages referencing other messages, when compiling the generated
  %% files. The `type_specs' option is equivalent to `{type_specs,true}'.
  %%
  %% The `verify' option specifies whether or not to generate code
  %% that verifies, during encoding, that values are of correct type and
  %% within range.  The `verify' option can have the following values:
  %% <dl>
  %%    <dt>`always'</dt><dd>Generate code that unconditionally
  %%        verifies values.</dd>
  