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<chapter>
  <header>
    <title>ASN1 Release Notes</title>
    <prepared>Kenneth Lundin</prepared>
    <responsible>Kenneth Lundin</responsible>
    <docno></docno>
    <approved>Kenneth Lundin</approved>
    <checked>Kenneth Lundin</checked>
    <date>97-10-07</date>
    <rev>A</rev>
    <file>notes_latest.sgml</file>
  </header>
  
  <p>This document describes the changes made to the asn1 application.

  <section>
    <title>ASN1 0.8.1</title>
    <p>This is the first release of the ASN1 application. This version is released
      for beta-testing. Some functionality will be added until the 1.0 version is
      released. A list of missing features and restrictions can be found in the
      chapter below.
    
    <section>
      <title>Missing features and other restrictions</title>
      <list>
	<item> 
	  <p>The encoding rules BER and PER (aligned) is supported. <em>PER (unaligned) 
	      IS NOT SUPPORTED</em>.
	<item> 
	  <p>NOT SUPPORTED types <c>ANY</c> and <c>ANY DEFINED BY</c> 
	    (is not in the standard any more).
	<item> 
	  <p>NOT SUPPORTED types <c>EXTERNAL</c> and <c>EMBEDDED-PDV</c>. 
	<item> 
	  <p>NOT SUPPORTED type <c>REAL</c> (planned to  be implemented). 
	<item> 
	  <p>The code generation support for value definitions in the ASN.1 notation is very limited
	    (planned to be enhanced).
	<item>
	  <p>The support for constraints is limited to:
	  <list>
	    <item><p>
		SizeConstraint	SIZE(X)
	    <item><p>
		SingleValue	(1)
	    <item><p>
		ValueRange	(X..Y)
	    <item><p>
		PermittedAlpabet FROM (but not for BMPString and UniversalString when generating PER).
	  </list>
	  <p>Complex expressions in constraints is not supported (planned to be extended).
	<item> 
	  <p>The current version of the compiler has very limited error checking:
	    <list>
	    <item><p>Stops at first syntax error.
	    <item><p>Does not stop when a reference to an undefined type is found , 
		but prints an error message. Compilation of the generated 
		Erlang module will then fail.
	    <item><p>A whole number of other semantical controls is currently missing. This
		means that the compiler will give little or bad help to detect what's wrong
		with an ASN.1 specification, but will mostly work very well when the
		ASN.1 specification is correct.
	  </list>
	<item> 
	  <p>The maximum INTEGER supported in this version is a signed 64 bit integer. This
	    limitation is probably quite reasonable. (Planned to be extended).
	<item> 
	  <p>Only AUTOMATIC TAGS supported for PER.
	<item> 
	  <p>Only EXPLICIT and IMPLICIT TAGS supported for BER.
	<item> 
	  <p>The compiler supports decoding of BER-data with indefinite length but it is 
	    not possible to produce data with indefinite length with the encoder. 
      </list>
    </section>
	  
  </section>
</chapter>



