| <html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>5.5.2. Initial Value</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_ASMFunctions.html" title="5.5. ASM Functions"><link rel="prev" href="def_AsmFunctionDef.html" title="5.5.1. ASM Function Definition"><link rel="next" href="def_AsmFunctionLocation.html" title="5.5.3. ASM Function Location"></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">5.5.2. Initial Value</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="def_AsmFunctionDef.html">Prev</a> </td><th align="center" width="60%">5.5. ASM Functions</th><td align="right" width="20%"> <a accesskey="n" href="def_AsmFunctionLocation.html">Next</a></td></tr></table><hr></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="def_InitialValue"></a>5.5.2. Initial Value</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_InitialValue_Description"></a>Description</th></tr><tr><td valign="top" align="left"><p> | |
| An <span class="strong"><strong>initial value</strong></span><a name="N12C1E" class="indexterm"></a> | |
| can be the part of the definition of an ASM function. It provides the definition of a slot initially storing a value at | |
| certain locations. | |
| </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_InitialValue_Syntax"></a>Syntax</th></tr><tr><td valign="top" align="left"><pre class="programlisting"> | |
| InitialValuesOptAST ::= <span class="token">;</span> | |
| | <span class="token">{</span> InitialValuesAST <span class="token">}</span> | |
| InitialValuesAST ::= InitialValueAST | |
| | InitialValuesAST InitialValueAST | |
| InitialValueAST ::= <a href="def_ActualParameter.html" title="5.8.3. Actual Parameters">ActualParameterDefAST</a> <span class="token">=</span> <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">ArithmeticTermAST</a> <span class="token">;</span> | |
| </pre><p> | |
| An <span class="strong"><strong>initial value</strong></span> is a value assignment to a <a href="def_AsmFunctionLocation.html" title="5.5.3. ASM Function Location">location</a>. | |
| </p><p> | |
| The <span class="strong"><strong>location</strong></span> is supplied as <a href="def_ActualParameter.html" title="5.8.3. Actual Parameters">actual parameters</a>, | |
| i.e. by a comma separated list of ASM <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">arithmetic terms</a>. | |
| </p><p> | |
| The value is determined by the evaluation of the <span class="strong"><strong>value tag</strong></span> | |
| that can also be an arbitrary ASM <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">arithmetic term</a>. | |
| </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_InitialValue_Semantics"></a>Semantics</th></tr><tr><td valign="top" align="left"><p> | |
| Since ASM functions defined in other machines can also be invoked, the | |
| interpreter provides lazy initialization for all ASM functions: these are | |
| <span class="emphasis"><em>initialized on-demand</em></span>, i.e. just before their first use. | |
| </p></td></tr></table></div><div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Caution: Constraints"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Caution]" src="images/caution.png"></td><th align="left"><a name="def_InitialValue_Constraints"></a>Constraints</th></tr><tr><td valign="top" align="left"><p> | |
| The number of the index elements (i.e. the dimension) must be equal to the <span class="emphasis"><em>arity</em></span> | |
| determined by the corresponding <a href="def_AsmFunctionDef.html" title="5.5.1. ASM Function Definition">ASM function definition</a>. | |
| </p></td></tr></table></div><div class="highlights"><a name="def_InitialValue_DefinedIn"></a><p><b>Defined In: </b> | |
| <a href="def_AsmFunctionDef.html" title="5.5.1. ASM Function Definition">ASM function definition</a> | |
| </p></div></div><div class="navfooter"><hr><table summary="Navigation footer" width="100%"><tr><td align="left" width="40%"><a accesskey="p" href="def_AsmFunctionDef.html">Prev</a> </td><td align="center" width="20%"><a accesskey="u" href="sec_ASMFunctions.html">Up</a></td><td align="right" width="40%"> <a accesskey="n" href="def_AsmFunctionLocation.html">Next</a></td></tr><tr><td valign="top" align="left" width="40%">5.5.1. ASM Function Definition </td><td align="center" width="20%"><a accesskey="h" href="index.html">Home</a></td><td valign="top" align="right" width="40%"> 5.5.3. ASM Function Location</td></tr></table></div></body></html> |