| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 1 | <!DOCTYPE html |
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| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 6 | <link rel="stylesheet" type="text/css" href="../css/ot.css" /> |
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| 8 | <title>OT/J Language Definition v1.3</title> |
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| 12 | <table class="nav"> |
| 13 | <tr> |
| 14 | <td class="back"><a id="top"></a><a href="s9.2.1.html" rel="prev"><< §9.2.1 Parameter substitution</a></td> |
| 15 | <td class="top"><a href="index.html" rel="contents">↑ Table of Contents ↑</a></td> |
| 16 | <td class="next"></td> |
| 17 | </tr> |
| 18 | </table> |
| 19 | <div class="breadcrumb"><a class="nav" href="s9.html" rel="section">§9 Value Dependent Classes</a> > <a class="nav" href="s9.2.html" rel="section">§9.2 Using classes with value parameters</a></div> |
| 20 | <div class="sect depth3" id="s9.2.2"> |
| Stephan Herrmann | 109893e | 2010-05-18 22:02:53 +0000 | [diff] [blame] | 21 | <h3 class="sect">§9.2.2 Type conformance<a class="img" href="s9.2.2.html" |
| 22 | title="PermaLink to §9.2.2 Type conformance"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| 23 | alt="" /></a></h3> |
| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 24 | <p>Two value dependent types (anchored types) are considered conform only if the anchors |
| 25 | of both types refer to <i>the same object(s)</i>. The compiler must be able to statically |
| 26 | analyze this anchor identity. |
| 27 | |
| 28 | </p> |
| 29 | <div class="subsect depth4" id="s9.2.2.a"> |
| Stephan Herrmann | 109893e | 2010-05-18 22:02:53 +0000 | [diff] [blame] | 30 | <h4 class="subsect">(a) <span class="title">Substitutions for type anchors</span><a class="img" href="s9.2.2.a.html" |
| 31 | title="PermaLink to (a) Substitutions for type anchors"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| 32 | alt="" /></a></h4> |
| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 33 | <p>Only two substitutions are considered for determining anchor identity: |
| 34 | |
| 35 | </p> |
| 36 | <ol> |
| 37 | <li>If a method signature uses <code>this</code> as the anchor of any of its types, |
| 38 | type checking an application of this method performs the following substitutions: |
| 39 | <br /> |
| 40 | A simple <code>this</code> expression is substituted by the actual call target |
| 41 | of the method application. |
| 42 | <br /> |
| 43 | A qualified <code>Outer.this</code> expression is substituted by the corresponding |
| 44 | enclosing instance of the call target. |
| 45 | </li> |
| 46 | <li>Assignments from a <code>final</code> identifier to another <code>final</code> |
| 47 | identifier are transitively followed, i.e., if <code>t1, t2</code> are final, |
| 48 | after an assignment <code>t1=t2</code> the types <code>C<@t1></code> and |
| 49 | <code>C<@t2></code> are considered identical. Otherwise <code>C<@t1></code> |
| 50 | and <code>C<@t2></code> are incommensurable. |
| 51 | <br /> |
| 52 | Attaching an actual parameter to a formal parameter in a method call is also considered |
| 53 | as an assignment with respect to this rule. |
| 54 | </li> |
| 55 | </ol> |
| 56 | </div> |
| 57 | <div class="subsect depth4" id="s9.2.2.b"> |
| Stephan Herrmann | 109893e | 2010-05-18 22:02:53 +0000 | [diff] [blame] | 58 | <h4 class="subsect">(b) <span class="title">Conformance of raw types</span><a class="img" href="s9.2.2.b.html" |
| 59 | title="PermaLink to (b) Conformance of raw types"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| 60 | alt="" /></a></h4> |
| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 61 | <p>After anchors have been proven identical, the raw types are checked for compatibility |
| 62 | using the standard Java rules. |
| 63 | |
| 64 | </p> |
| 65 | </div> |
| 66 | </div> |
| 67 | <table class="nav"> |
| 68 | <tr> |
| 69 | <td class="back"><a href="s9.2.1.html" rel="prev"><< §9.2.1 Parameter substitution</a></td> |
| 70 | <td class="top"><a href="index.html" rel="contents">↑ Table of Contents ↑</a></td> |
| 71 | <td class="next"></td> |
| 72 | </tr> |
| 73 | </table> |
| 74 | <div class="breadcrumb"><a class="nav" href="s9.html" rel="section">§9 Value Dependent Classes</a> > <a class="nav" href="s9.2.html" rel="section">§9.2 Using classes with value parameters</a></div> |
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| Stephan Herrmann | 109893e | 2010-05-18 22:02:53 +0000 | [diff] [blame] | 77 | <hr /><a class="w3c img" href="http://jigsaw.w3.org/css-validator/check/referer" |
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| 79 | width="88" /></a><address>© Stephan Herrmann, Christine Hundt, Marco Mosconi</address> |
| Stephan Herrmann | 8f0fa31 | 2010-06-08 18:24:55 +0000 | [diff] [blame^] | 80 | OT/J version 1.3 — last modified: 2010-06-08 |
| Stephan Herrmann | 0166441 | 2010-04-01 20:28:43 +0000 | [diff] [blame] | 81 | </div> |
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