title: erlang: ei_get_type() : where are the defined constants for the 'type' field?
body: <p>I am trying to use <em>ei_get_type()</em> (<a href="http://www.erlang.org/doc/man/ei.html" rel="noreferrer">ei</a>) but I am having trouble finding where the 'type' field is documented. I've looked in <strong>ei.h</strong> but all I could find was a list of constants starting with "ERL_".</p>
  
  <pre><code>#define ERL_SMALL_INTEGER_EXT 'a'
  #define ERL_INTEGER_EXT       'b'
  #define ERL_FLOAT_EXT         'c'
  #define ERL_ATOM_EXT          'd'
  #define ERL_REFERENCE_EXT     'e'
  #define ERL_NEW_REFERENCE_EXT 'r'
  #define ERL_PORT_EXT          'f'
  #define ERL_PID_EXT           'g'
  #define ERL_SMALL_TUPLE_EXT   'h'
  #define ERL_LARGE_TUPLE_EXT   'i'
  #define ERL_NIL_EXT           'j'
  #define ERL_STRING_EXT        'k'
  #define ERL_LIST_EXT          'l'
  #define ERL_BINARY_EXT        'm'
  #define ERL_SMALL_BIG_EXT     'n'
  #define ERL_LARGE_BIG_EXT     'o'
  #define ERL_NEW_FUN_EXT   'p'
  #define ERL_FUN_EXT           'u'
  </code></pre>
  
  <p>Is this the correct list?  I am unsure because the prototype of <em>er_get_type()</em> has *int ** for the type field whereas the <em>ei.h</em> file defines <em>char</em> the above constants.</p>
  
  <p>NOTE: There are other 'constants' used in the 'erl_interface' package that aren't listed here.</p>