<html>
  <head>
    <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    When I use beam_lib:chunks/2 I get tuples that are easy to identity
    as type information(*).<br>
    When I turn the chunks into an abstract tree I do not understand how
    to find the type info any more. How should a fun for
    erl_syntax_lib:fold/3 look, to identify the type information nodes?<br>
    <br>
    <br>
    bengt<br>
    (*)<br>
           [{attribute,64,type,<br>
            {option_name,<br>
             {type,64,union,<br>
              [{atom,64,use_stdio},<br>
               {atom,65,cd},<br>
               {atom,66,compressed},<br>
               {atom,67,packet},<br>
               {atom,68,env},<br>
               {atom,69,start_timeout},<br>
               {atom,70,call_timeout},<br>
               {atom,71,buffer_size}]},<br>
             []}},<br>
    ...]<br>
    <br>
    <br>
    <div class="moz-cite-prefix">On 04/10/2015 08:41 AM, Vlad Dumitrescu
      wrote:<br>
    </div>
    <blockquote
cite="mid:CAA-EFXvAiJLnfHKkQnP+cKVMmRYDB94Ji7a=iwUyr=qpsi4jfg@mail.gmail.com"
      type="cite">
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
      <div dir="ltr">Hi Bengt,
        <div><br>
        </div>
        <div>You have to extract this information from
          beam_lib:chunks(BEAM, [abstract_code]) by means of
          erl_syntax_lib:fold/3 to keep only the typespecs. It would be
          nice to have a higher-level library that gives access to these
          internals.</div>
        <div><br>
        </div>
        <div>regards,</div>
        <div>Vlad</div>
        <div><br>
        </div>
      </div>
      <div class="gmail_extra"><br>
        <div class="gmail_quote">On Fri, Apr 10, 2015 at 8:23 AM, Bengt
          Kleberg <span dir="ltr"><<a moz-do-not-send="true"
              href="mailto:bengt.kleberg@ericsson.com" target="_blank">bengt.kleberg@ericsson.com</a>></span>
          wrote:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">Greetings,<br>
            <br>
            How do I find type information at run time?<br>
            <br>
            A very nice Erlang module takes an options list. The options
            are -type defined and -export_type'ed.<br>
            How do another module get that information during run time?<br>
            <br>
            I thought that it might be in very_nice:module_info(attributes),
            but no luck.<br>
            <br>
            <br>
            bengt<br>
            <br>
            _______________________________________________<br>
            erlang-questions mailing list<br>
            <a moz-do-not-send="true"
              href="mailto:erlang-questions@erlang.org" target="_blank">erlang-questions@erlang.org</a><br>
            <a moz-do-not-send="true"
              href="http://erlang.org/mailman/listinfo/erlang-questions"
              target="_blank">http://erlang.org/mailman/listinfo/erlang-questions</a><br>
          </blockquote>
        </div>
        <br>
      </div>
    </blockquote>
    <br>
  </body>
</html>