| <html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>4.1.1. ASM Rule Definition</title><link href="style.css" rel="stylesheet" type="text/css"><meta content="DocBook XSL Stylesheets V1.72.0" name="generator"><link rel="start" href="index.html" title="The VIATRA2 Model Transformation Framework"><link rel="up" href="sec_DefASMRule.html" title="4.1. ASM Rule Definition and Invocation"><link rel="prev" href="sec_DefASMRule.html" title="4.1. ASM Rule Definition and Invocation"><link rel="next" href="def_AsmRuleInvoc.html" title="4.1.2. ASM Rule Invocation"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table summary="Navigation header" width="100%"><tr><th align="center" colspan="3">4.1.1. ASM Rule Definition</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="sec_DefASMRule.html">Prev</a> </td><th align="center" width="60%">4.1. ASM Rule Definition and Invocation</th><td align="right" width="20%"> <a accesskey="n" href="def_AsmRuleInvoc.html">Next</a></td></tr></table><hr></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="def_AsmRuleDef"></a>4.1.1. ASM Rule Definition</h4></div></div></div><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Tip: Description"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Tip]" src="images/tip.png"></td><th align="left"><a name="def_AsmRuleDef_Description"></a>Description</th></tr><tr><td valign="top" align="left"><p> | |
| An <span class="strong"><strong>ASM rule definition</strong></span><a name="N11131" class="indexterm"></a> | |
| is the building block of an ASM program. When invoked, its formal parameters are substituted with actual parameters, and its body is called. | |
| </p></td></tr></table></div><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Important: Syntax"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Important]" src="images/important.png"></td><th align="left"><a name="def_AsmRuleDef_Syntax"></a>Syntax</th></tr><tr><td valign="top" align="left"><pre class="programlisting"> | |
| AsmRuleDefAST ::= <a href="def_Annotation.html" title="1.2.2. Annotation">OptAnnotationsAST</a> <span class="token">rule</span> <a href="def_ModelElementName.html" title="5.7.1. Model Element Name">TypeNameAST</a> DirectedFormalParameterDefAST <span class="token">=</span> <a href="def_AsmRuleInvoc.html" title="4.1.2. ASM Rule Invocation">AsmRuleInvocAST</a> | |
| DirectedFormalParameterDefAST ::= <span class="token">(</span> <a href="def_FormalParameter.html" title="5.8.1. Formal Parameters">FormalParamsAST</a> <span class="token">)</span> | |
| | <span class="token">(</span> <span class="token">)</span> | |
| </pre><p> | |
| An <span class="strong"><strong>ASM rule definition</strong></span> is identified by a <a href="def_ModelElementName.html" title="5.7.1. Model Element Name">name</a>, | |
| it has a <a href="def_DirectedFormalParameter.html" title="5.8.2. Directed Formal Parameters">list of directed formal parameters</a>, and an | |
| <a href="def_AsmRuleInvoc.html" title="4.1.2. ASM Rule Invocation">ASM rule invocation</a> as body. | |
| </p></td></tr></table></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note: Semantics"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left"><a name="def_AsmRuleDef_Semantics"></a>Semantics</th></tr><tr><td valign="top" align="left"><p> | |
| An <span class="strong"><strong>ASM rule definition</strong></span> can be invoked by a | |
| <a href="def_CallRule.html" title="4.2.2. Call Rule">call rule</a>. When invoked, the formal parameters are substituted | |
| by the actual parameters of the call, and the <a href="def_AsmRuleInvoc.html" title="4.1.2. ASM Rule Invocation">body</a> of the ASM rule is called. | |
| </p><p> | |
| The entry point of an ASM program is a special user-defined rule called <span class="emphasis"><em>main</em></span>. | |
| </p><p> | |
| Two rules may have identical names as long as their arity (the number of parameters) is different. | |
| </p></td></tr></table></div><div class="highlights"><a name="def_AsmRuleDef_Remark"></a><p><b>Remark. </b> | |
| If the <span class="emphasis"><em>main</em></span>rule of a machine has an input parameter then this parameter can | |
| set by the user when the transformation starts execution. The actual values | |
| of the input parameters should be defined in the pop-up window separated by | |
| spaces (' '). Currently, each input parameter is considered to be a string. | |
| Most frequently, the <span class="strong"><strong>body</strong></span> of an ASM rule definition | |
| is a <a href="def_SequentialRule.html" title="4.3.2. Sequential Rule">sequential rule</a>, but it can be arbitrary | |
| <a href="def_AsmRuleInvoc.html" title="4.1.2. ASM Rule Invocation">ASM rule invocations</a>. | |
| </p></div><div class="highlights"><a name="def_AsmRuleDef_DefinedIn"></a><p><b>Defined In: </b> | |
| <a href="def_Machine.html" title="1.2.1. GTASM Machine Definition">machine</a> | |
| </p></div></div><div class="navfooter"><hr><table summary="Navigation footer" width="100%"><tr><td align="left" width="40%"><a accesskey="p" href="sec_DefASMRule.html">Prev</a> </td><td align="center" width="20%"><a accesskey="u" href="sec_DefASMRule.html">Up</a></td><td align="right" width="40%"> <a accesskey="n" href="def_AsmRuleInvoc.html">Next</a></td></tr><tr><td valign="top" align="left" width="40%">4.1. ASM Rule Definition and Invocation </td><td align="center" width="20%"><a accesskey="h" href="index.html">Home</a></td><td valign="top" align="right" width="40%"> 4.1.2. ASM Rule Invocation</td></tr></table></div></body></html> |