CR0416-Passing_omit_to_value_formal_parameters.md

  

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ETSI's Bug Tracker - Part 01: TTCN-3 Core Language
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<td class="print">0000416</td>
<td class="print">Part 01: TTCN-3 Core Language</td>
<td class="print">Clarification</td>
<td class="print">public</td>
<td class="print">24-11-2006 14:34</td>
<td class="print">12-03-2008 10:24</td>
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<td class="print-category">Reporter</td>
<td class="print">Stephan Schulz</td>
<td colspan="4" class="print"> </td>
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<tr class="even print">
<td class="print-category">Assigned To</td>
<td class="print">Ina Schieferdecker</td>
<td colspan="4" class="print"> </td>
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<tr class="odd print">
<td class="print-category">Priority</td>
<td class="print">high</td>
<td class="print-category">Severity</td>
<td class="print">block</td>
<td class="print-category">Reproducibility</td>
<td class="print">N/A</td>
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<td class="print-category">Status</td>
<td class="print">closed</td>
<td class="print-category">Resolution</td>
<td class="print">fixed</td>
<td colspan="2" class="print"> </td>
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<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>
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<td class="print-category">Product Version</td>
<td class="print">v3.1.1 (published 2005-06)</td>
<td colspan="4" class="print"> </td>
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<td class="print-category">Target Version</td>
<td class="print">v3.3.2 (published 2008-04)</td>
<td class="print-category">Fixed in Version</td>
<td class="print">v3.3.2 (published 2008-04)</td>
<td colspan="2" class="print"> </td>
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<td class="print-category">Clause Reference(s)</td>
<td colspan="4" class="print">-</td>
<td></td>
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<td class="print-category">Source (company - Author)</td>
<td colspan="4" class="print">dr. György Réthy, Ericsson</td>
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<td colspan="6" class="print-spacer"><hr /></td>
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<td class="print-category">Summary</td>
<td colspan="5" class="print">0000416: Passing omit to value formal
parameters</td>
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<td class="print-category">Description</td>
<td colspan="5" class="print">The TTCN-3 standard today does not defines
the term "value". In common sense value means "In computer science, a
value may be a number, literal string, array and anything that can be
treated as if it were a number. ... The exact definition varies across
programming languages." (from the English Wikipedia, Value (computer
science) item). "Nothing" is not a value, i.e. omit should not be
considered as value in TTCN-3. This meaning is strengthened by the
TTCN-3 standard, where omit is mentioned as a matching mechanism (though
it can also be PART of a value, i.e. assigned to optional fields. Titan
follows this approach and allows to pass real specific values to value
parameters only but not omit. This provides a big advantage: it is
sufficient to check the "value" of a value formal parameter when it is
passed, no need for subsequent checks when it is used e.g. in
expressions.<br />
However, in many cases it would be useful to allow formal parameters
accepting specific values and omit, e.g. when this parameter is passed
to optional template fields in sending operations.<br />
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<td class="print-category">Steps To Reproduce</td>
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<td class="print-category">Additional Information</td>
<td colspan="5" class="print">It is proposed to make a distinction
between value formal parameters allowing omit and not allowing omit in
the TTCN-3 language.<br />
<br />
Formal parameters<br />
To denote that the special value omit is allowed for a value formal
parameter, the optional keyword shall be used in the formal parameter
list of test cases, functions, altsteps or templates. In the
testcase/function/altstep the optional parameter can be compared with
omit to determine if a concrete value has been provided or omit was
given when calling it.<br />
Example code:<br />
function f_MyFunc1 (optional integer par)<br />
{<br />
   if (par==omit) {<br />
      // omit was given for par<br />
   } else {<br />
      // value was provided for par<br />
   }<br />
}<br />
The parameters with default value (see CR 406) and optional parameters
are independent features. The user can combine the two features,<br />
Example code:<br />
function f_MyFunc2(optional integer par1, optional integer par2 := omit,
integer par3 := 5 )<br />
{ ... }<br />
<br />
Actual parameters<br />
Optional value parameters may be called with a concrete value or with
omit as actual parameter.<br />
Example code:<br />
f_MyFunc1(11);<br />
f_MyFunc1(omit);<br />
f_MyFunc2(omit); // par1 &amp; par2 will have the actual value
omit,<br />
                 // par3 will have the actual value 5<br />
<br />
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<td class="print-category">Tags</td>
<td colspan="5" class="print">No tags attached.</td>
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<td class="print-category">Relationships</td>
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<td class="print-category">Attached Files</td>
<td colspan="5" class="print"><img
src="http://oldforge.etsi.org/mantis/images/fileicons/zip.gif"
alt="zip" /> CR_416_v2.zip (890,821) <span class="italic">06-12-2007
11:51</span><br />
http://oldforge.etsi.org/mantis/file_download.php?file_id=1234&amp;type=bug<br />
<img src="http://oldforge.etsi.org/mantis/images/fileicons/zip.gif"
alt="zip" /> CR_416_v3.zip (885,232) <span class="italic">06-12-2007
17:01</span><br />
http://oldforge.etsi.org/mantis/file_download.php?file_id=1242&amp;type=bug<br />
<img src="http://oldforge.etsi.org/mantis/images/fileicons/zip.gif"
alt="zip" /> CR_416_v4.zip (869,220) <span class="italic">06-12-2007
17:43</span><br />
http://oldforge.etsi.org/mantis/file_download.php?file_id=1245&amp;type=bug<br />
<img src="http://oldforge.etsi.org/mantis/images/fileicons/zip.gif"
alt="zip" /> CR_416_v5.zip (886,077) <span class="italic">06-12-2007
18:30</span><br />
http://oldforge.etsi.org/mantis/file_download.php?file_id=1247&amp;type=bug</td>
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<td class="form-title">Issue History</td>
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<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>
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<td class="print">24-11-2006 14:34</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=56">Stephan
Schulz</a></td>
<td class="print">New Issue</td>
<td class="print"></td>
<td></td>
<td></td>
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<tr class="even print">
<td class="print">24-11-2006 14:34</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=56">Stephan
Schulz</a></td>
<td class="print">Clause Reference(s)</td>
<td class="print">=&gt; -</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">24-11-2006 14:34</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=56">Stephan
Schulz</a></td>
<td class="print">Source (company - Author)</td>
<td class="print">=&gt; dr. György Réthy, Ericsson</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">15-06-2007 19:15</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=56">Stephan
Schulz</a></td>
<td class="print">Status</td>
<td class="print">new =&gt; assigned</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">15-06-2007 19:15</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=56">Stephan
Schulz</a></td>
<td class="print">Assigned To</td>
<td class="print">=&gt; Ina Schieferdecker</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">13-10-2007 19:22</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina
Schieferdecker</a></td>
<td class="print">Assigned To</td>
<td class="print">Ina Schieferdecker =&gt; developer_u</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">17-10-2007 12:41</td>
<td class="print">user10</td>
<td class="print">Assigned To</td>
<td class="print">developer_u =&gt; Thomas Deiß</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">18-10-2007 12:10</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina
Schieferdecker</a></td>
<td class="print">Target Version</td>
<td class="print">=&gt; Edition 4.1.1 (not yet published)</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 11:51</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">File Added: CR_416_v2.zip</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 11:52</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Note Added: 0004372</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 11:52</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Assigned To</td>
<td class="print">Thomas Deiß =&gt; Gyorgy Rethy</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 11:52</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Resolution</td>
<td class="print">open =&gt; fixed</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 11:52</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Target Version</td>
<td class="print">Edition 4.1.1 (not yet published) =&gt; Edition 3.3.1
(not yet published)</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 16:59</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Note Added: 0004396</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 17:01</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">File Added: CR_416_v3.zip</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 17:43</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy
Rethy</a></td>
<td class="print">File Added: CR_416_v4.zip</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 17:45</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: 0004401</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 17:45</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; Jens Grabowski</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 18:05</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=82">Jens
Grabowski</a></td>
<td class="print">Assigned To</td>
<td class="print">Jens Grabowski =&gt; Thomas Deiß</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 18:30</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">File Added: CR_416_v5.zip</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">06-12-2007 18:34</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Note Added: 0004407</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">06-12-2007 18:34</td>
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a></td>
<td class="print">Assigned To</td>
<td class="print">Thomas Deiß =&gt; Ina Schieferdecker</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">07-12-2007 09:38</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">assigned =&gt; resolved</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">07-12-2007 10:05</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>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">07-12-2007 10:05</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: 0004417</td>
<td class="print"></td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">07-12-2007 10:05</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 3.3.1 (not yet published)</td>
<td></td>
<td></td>
</tr>
<tr class="odd print">
<td class="print">12-03-2008 10:22</td>
<td class="print">user10</td>
<td class="print">Fixed in Version</td>
<td class="print">Edition 3.3.1 --will not be published, see 3.3.2 =&gt;
Edition 3.3.2 (not yet published)</td>
<td></td>
<td></td>
</tr>
<tr class="even print">
<td class="print">12-03-2008 10:24</td>
<td class="print">user10</td>
<td class="print">Target Version</td>
<td class="print">Edition 3.3.1 --will not be published, see 3.3.2 =&gt;
Edition 3.3.2 (not yet published)</td>
<td></td>
<td></td>
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<td class="print">(0004372)</td>
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<tr class="even">
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a>   </td>
</tr>
<tr class="odd">
<td class="print">06-12-2007 11:52   </td>
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<td class="print">solution provided (already checked by Gyorgy
once)</td>
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<td colspan="2" class="print-spacer"><hr /></td>
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data-cellspacing="1">
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<td class="print">(0004396)</td>
</tr>
<tr class="even">
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a>   </td>
</tr>
<tr class="odd">
<td class="print">06-12-2007 16:59   </td>
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<td class="nopad" data-valign="top" width="85%"><table class="hide"
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<td class="print">New solution (R3). Introduce restrictions of
templates, currently just one restriction is allowed (omit). 'template
(omit)' can be shortened to omit. incorrect cases are not required to be
detected at compile time, similar to type compatibility.</td>
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</tbody>
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<td colspan="2" class="print-spacer"><hr /></td>
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<td class="nopad" data-valign="top" width="20%"><table class="hide"
data-cellspacing="1">
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<td class="print">(0004401)</td>
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<tr class="even">
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=127">Gyorgy
Rethy</a>   </td>
</tr>
<tr class="odd">
<td class="print">06-12-2007 17:45   </td>
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<td class="print">I basically agree both with the solution and handling
it in the standard's text. Made some modifications to the text
proposed.</td>
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<td class="print">(0004407)</td>
</tr>
<tr class="even">
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=112">Thomas
Deiß</a>   </td>
</tr>
<tr class="odd">
<td class="print">06-12-2007 18:34   </td>
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<td class="print">Description made more restrictive (no hints on more
general usage).<br />
Example added.<br />
Parentheses changed to curly brackets to avoid confusion with value
lists.<br />
<br />
please check the additional comments in the BNF.</td>
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</tr>
<tr class="even">
<td colspan="2" class="print-spacer"><hr /></td>
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<tr class="odd">
<td class="nopad" data-valign="top" width="20%"><table class="hide"
data-cellspacing="1">
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<tr class="odd">
<td class="print">(0004417)</td>
</tr>
<tr class="even">
<td class="print"><a
href="http://oldforge.etsi.org/mantis/view_user_page.php?id=81">Ina
Schieferdecker</a>   </td>
</tr>
<tr class="odd">
<td class="print">07-12-2007 10:05   </td>
</tr>
</tbody>
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<td class="nopad" data-valign="top" width="85%"><table class="hide"
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<tr class="odd">
<td class="print">just little wording changes</td>
</tr>
</tbody>
</table></td>
</tr>
</tbody>
</table>