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<br /><table class="width100" cellspacing="1"><tr><td class="form-title" colspan="6"><div class="center">ETSI's Bug Tracker - Part 01: TTCN-3 Core Language</div></td></tr><tr><td class="form-title" colspan="6">View Issue Details</td></tr><tr><td class="print-spacer" colspan="6"><hr size="1" /></td></tr><tr class="print-category"><td class="print" width="16%">ID</td><td class="print" width="16%">Project</td><td class="print" width="16%">Category</td><td class="print" width="16%">View Status</td><td class="print" width="16%">Date Submitted</td><td class="print" width="16%">Last Update</td></tr><tr class="print"><td class="print">0006017</td><td class="print">Part 01: TTCN-3 Core Language</td><td class="print">Technical</td><td class="print">public</td><td class="print">16-04-2012 19:54</td><td class="print">06-08-2012 17:22</td></tr><tr><td class="print-spacer" colspan="6"><hr size="1" /></td></tr><tr class="print"><td class="print-category">Reporter</td><td class="print">Andras Kovacs</td><td class="print" colspan="4">&#160;</td></tr><tr class="print"><td class="print-category">Assigned To</td><td class="print">Ina Schieferdecker</td><td class="print" colspan="4">&#160;</td></tr><tr class="print"><td class="print-category">Priority</td><td class="print">normal</td><td class="print-category">Severity</td><td class="print">minor</td><td class="print-category">Reproducibility</td><td class="print">N/A</td></tr><tr class="print"><td class="print-category">Status</td><td class="print">closed</td><td class="print-category">Resolution</td><td class="print">fixed</td><td class="print" colspan="2">&#160;</td></tr><tr class="print"><td class="print-category">Platform</td><td class="print"></td><td class="print-category">OS</td><td class="print"></td><td class="print-category">OS Version</td><td class="print"></td></tr><tr class="print"><td class="print-category">Product Version</td><td class="print"></td><td class="print" colspan="4">&#160;</td></tr><tr><td class="print-category">Target Version</td><td class="print">v4.5.1 (published 2013-04)</td><td class="print-category">Fixed in Version</td><td class="print">v4.5.1 (published 2013-04)</td><td class="print" colspan="2">&#160;</td></tr><tr class="print"><td class="print-category">Clause Reference(s)</td><td class="print" colspan="4">15.11, A.1.6.</td></tr><tr class="print"><td class="print-category">Source  (company  - Author)</td><td class="print" colspan="4">STF433     </td></tr><tr><td class="print-spacer" colspan="6"><hr size="1" /></td></tr><tr class="print"><td class="print-category">Summary</td><td class="print" colspan="5">0006017: [Part 01: TTCN-3 Core Language] BNF ambiguity for concatenation of string templates</td></tr><tr class="print"><td class="print-category">Description</td><td class="print" colspan="5">BNF 88, 89, and 90 are conflicting: MatchingSymbol definition allows CharStringMatch, which allows &amp; (BNF 109) but BNF 88 also allows &amp; for the template construction<br />
Therefore the interpretation of the BNF rules is ambiguous.</td></tr><tr class="print"><td class="print-category">Steps To Reproduce</td><td class="print" colspan="5"></td></tr><tr class="print"><td class="print-category">Additional Information</td><td class="print" colspan="5"></td></tr><tr class="print"><td class="print-category">Tags</td><td class="print" colspan="5">No tags attached.</td></tr><tr class="print"><td class="print-category">Relationships</td><td class="print" colspan="5"></td></tr><tr class="print"><td class="print-category">Attached Files</td><td class="print" colspan="5"><img src="http://oldforge.etsi.org/mantis/images/fileicons/doc.gif" alt="docx" />&#160;CR_6017_resolution_v1.docx (44,400) <span class="italic">13-07-2012 14:04</span><br />http://oldforge.etsi.org/mantis/file_download.php?file_id=2701&amp;type=bug</td></tr><tr><td class="print-spacer" colspan="6"><hr size="1" /></td></tr><tr><td class="form-title">Issue History</td></tr><tr class="print-category"><td class="row-category-history">Date Modified</td><td class="row-category-history">Username</td><td class="row-category-history">Field</td><td class="row-category-history">Change</td></tr><tr class="print"><td class="print">16-04-2012 19:54</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=607">Andras Kovacs</a></td><td class="print">New Issue</td><td class="print"></td></tr><tr class="print"><td class="print">16-04-2012 19:54</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=607">Andras Kovacs</a></td><td class="print">Clause Reference(s)</td><td class="print"> =&gt; 15.11, A.1.6.</td></tr><tr class="print"><td class="print">16-04-2012 19:54</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=607">Andras Kovacs</a></td><td class="print">Source  (company  - Author)</td><td class="print"> =&gt; STF433     </td></tr><tr class="print"><td class="print">19-04-2012 11:44</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=508">Jacob Wieland - Spirent</a></td><td class="print">Note Added: 0010559</td><td class="print"></td></tr><tr class="print"><td class="print">09-07-2012 16:54</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a></td><td class="print">Project</td><td class="print">TTCN-3 Change Requests =&gt; Part 01: TTCN-3 Core Language</td></tr><tr class="print"><td class="print">10-07-2012 12:02</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Note Added: 0010745</td><td class="print"></td></tr><tr class="print"><td class="print">10-07-2012 12:02</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Assigned To</td><td class="print"> =&gt; Tomas Urban</td></tr><tr class="print"><td class="print">10-07-2012 12:02</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Status</td><td class="print">new =&gt; assigned</td></tr><tr class="print"><td class="print">10-07-2012 12:02</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Target Version</td><td class="print"> =&gt; Edition 4.5.1</td></tr><tr class="print"><td class="print">12-07-2012 11:35</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">Note Added: 0010871</td><td class="print"></td></tr><tr class="print"><td class="print">12-07-2012 11:35</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">Assigned To</td><td class="print">Tomas Urban =&gt; Gyorgy Rethy</td></tr><tr class="print"><td class="print">13-07-2012 10:11</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Note Added: 0010910</td><td class="print"></td></tr><tr class="print"><td class="print">13-07-2012 10:12</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a></td><td class="print">Assigned To</td><td class="print">Gyorgy Rethy =&gt; Tomas Urban</td></tr><tr class="print"><td class="print">13-07-2012 14:04</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">File Added: CR_6017_resolution_v1.docx</td><td class="print"></td></tr><tr class="print"><td class="print">13-07-2012 14:06</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">Note Added: 0010926</td><td class="print"></td></tr><tr class="print"><td class="print">13-07-2012 14:07</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">Assigned To</td><td class="print">Tomas Urban =&gt; Ina Schieferdecker</td></tr><tr class="print"><td class="print">13-07-2012 14:07</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a></td><td class="print">Status</td><td class="print">assigned =&gt; resolved</td></tr><tr class="print"><td class="print">06-08-2012 17:22</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a></td><td class="print">Note Added: 0010978</td><td class="print"></td></tr><tr class="print"><td class="print">06-08-2012 17:22</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a></td><td class="print">Status</td><td class="print">resolved =&gt; closed</td></tr><tr class="print"><td class="print">06-08-2012 17:22</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a></td><td class="print">Resolution</td><td class="print">open =&gt; fixed</td></tr><tr class="print"><td class="print">06-08-2012 17:22</td><td class="print"><a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a></td><td class="print">Fixed in Version</td><td class="print"> =&gt; Edition 4.5.1</td></tr></table>
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				(0010559)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=508">Jacob Wieland - Spirent</a>&#160;&#160;&#160;
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				19-04-2012 11:44&#160;&#160;&#160;
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				As far as I remember, this is restricted by comments at the various rules.			</td>
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				(0010745)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a>&#160;&#160;&#160;
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				10-07-2012 12:02&#160;&#160;&#160;
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				STF discussion 2012-07-10:<br />
Check the issue.			</td>
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				(0010871)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a>&#160;&#160;&#160;
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				12-07-2012 11:35&#160;&#160;&#160;
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				The BNF rule numbers used in the original CR are related to the standard version 4.3.1. In the most recent standard, the mentioned rules are numbered as follows:<br />
91.SimpleSpec ::= (SingleExpression [&quot;&amp;&quot; SimpleTemplateSpec]) | SimpleTemplateSpec<br />
92.SimpleTemplateSpec ::= CharStringMatch | (SingleTemplateExpression [&quot;&amp;&quot; SimpleSpec])<br />
93.SingleTemplateExpression ::= MatchingSymbol | (TemplateRefWithParList [ExtendedFieldReference])<br />
112.CharStringMatch ::= PatternKeyword PatternParticle {&quot;&amp;&quot; PatternParticle}<br />
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I think the possible conflict is a question of BNF interpretation. E.g. pattern &quot;abc&quot; &amp; v_ref1 can be indeed resolved in two ways, either using 91, 92 and 112 (interpretting v_ref1 as a PatternParticle from the rule 112) or using rules 91, 92, 93, 112, 92 and 91 (interpretting v_ref1 as SimpleSpec from the rule 92).<br />
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However, BNF are usually interpretted so that the lower lying rules take precedence over parent rules. This is similar to the standard way of resolving shift/reduce conflicts in parsers when shift is prefered over reduce. Thus, v_ref1 from the example shall be always interpretted as a PatternParticle.<br />
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In my opinion the BNF rules are written correctly and there's no need to change them in order to avoid this kind of conflict. Nevertheless, I think that there is one change that can be made:<br />
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Rule 92 can be simplified by removing CharStringMatch, because the second part of the rule already includes it (SingleTemplateExpression -&gt; MatchingSymbol -&gt; CharStringMatch).<br />
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GyÃ¶rgy, could you please add your comment on this?			</td>
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				(0010910)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy Rethy</a>&#160;&#160;&#160;
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				13-07-2012 10:11&#160;&#160;&#160;
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				I agree with your assumption. Actually, if I got the original reported issue correctly, removing CharStringMatch from SimpleTemplateSpec will also solve the original problem.			</td>
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				(0010926)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=659">Tomas Urban</a>&#160;&#160;&#160;
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				13-07-2012 14:06&#160;&#160;&#160;
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				Resolved as requested. Please check.			</td>
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				(0010978)
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				<a href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina Schieferdecker</a>&#160;&#160;&#160;
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				06-08-2012 17:22&#160;&#160;&#160;
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				as proposed			</td>
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