| <html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>5.8.1. Formal Parameters</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_Parameters.html" title="5.8. Parameters and Variable Lists"><link rel="prev" href="sec_Parameters.html" title="5.8. Parameters and Variable Lists"><link rel="next" href="def_DirectedFormalParameter.html" title="5.8.2. Directed Formal Parameters"></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">5.8.1. Formal Parameters</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="sec_Parameters.html">Prev</a> </td><th align="center" width="60%">5.8. Parameters and Variable Lists</th><td align="right" width="20%"> <a accesskey="n" href="def_DirectedFormalParameter.html">Next</a></td></tr></table><hr></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="def_FormalParameter"></a>5.8.1. Formal Parameters</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_FormalParameter_Description"></a>Description</th></tr><tr><td valign="top" align="left"><p> | |
| <span class="strong"><strong>Formal parameters</strong></span> | |
| <a name="N12F68" class="indexterm"></a> | |
| <a name="N12F6D" class="indexterm"></a> | |
| define the interface of a graph pattern by a list of | |
| <a href="def_PatternVariable.html" title="2.1.6. Pattern Variable">pattern variables</a>. | |
| </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_FormalParameter_Syntax"></a>Syntax</th></tr><tr><td valign="top" align="left"><pre class="programlisting"> | |
| FormalParamsAST ::= <a href="def_PatternVariable.html" title="2.1.6. Pattern Variable">PatternVariableDefAST</a> | |
| | FormalParamsAST <span class="token">,</span> <a href="def_PatternVariable.html" title="2.1.6. Pattern Variable">PatternVariableDefAST</a> | |
| </pre><p> | |
| <span class="strong"><strong>Formal parameters</strong></span> is a list of pattern variables separated by | |
| commas. It can contain an arbitrary number of variables (including none). | |
| </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_FormalParameter_Semantics"></a>Semantics</th></tr><tr><td valign="top" align="left"><p> | |
| In case of <span class="strong"><strong>formal parameters</strong></span> | |
| the direction of the parameters is not defined | |
| (in contrast to the <a href="def_DirectedFormalParameter.html" title="5.8.2. Directed Formal Parameters">directed formal parameters</a>). The | |
| variables can be used both for input and output purposes depending on the | |
| the invoking environment. Those variables that are bound | |
| before the invocation of the pattern are the input variables and those that | |
| are unbound are output variables. | |
| </p></td></tr></table></div><div class="highlights"><a name="def_FormalParameter_UsedBy"></a><p><b>Used By: </b> | |
| <a href="def_GraphPatternDef.html" title="2.1.1. Graph Pattern Definition">graph pattern definition</a> | |
| </p></div><div class="highlights"><a name="def_FormalParameter_SeeAlso"></a><p><b>See Also: </b> | |
| <a href="def_DirectedFormalParameter.html" title="5.8.2. Directed Formal Parameters">directed formal parameter</a>, | |
| <a href="def_ActualParameter.html" title="5.8.3. Actual Parameters">actual parameter</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_Parameters.html">Prev</a> </td><td align="center" width="20%"><a accesskey="u" href="sec_Parameters.html">Up</a></td><td align="right" width="40%"> <a accesskey="n" href="def_DirectedFormalParameter.html">Next</a></td></tr><tr><td valign="top" align="left" width="40%">5.8. Parameters and Variable Lists </td><td align="center" width="20%"><a accesskey="h" href="index.html">Home</a></td><td valign="top" align="right" width="40%"> 5.8.2. Directed Formal Parameters</td></tr></table></div></body></html> |