<html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>4.2.6.&nbsp;Print Rule</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_ASMSimpleRules.html" title="4.2.&nbsp;Simple ASM Rules"><link rel="prev" href="def_UpdateRule.html" title="4.2.5.&nbsp;Update Rule"><link rel="next" href="def_LogRule.html" title="4.2.7.&nbsp;Log Rule"></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">4.2.6.&nbsp;Print Rule</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="def_UpdateRule.html">Prev</a>&nbsp;</td><th align="center" width="60%">4.2.&nbsp;Simple ASM Rules</th><td align="right" width="20%">&nbsp;<a accesskey="n" href="def_LogRule.html">Next</a></td></tr></table><hr></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="def_PrintRule"></a>4.2.6.&nbsp;Print Rule</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_PrintRule_Description"></a>Description</th></tr><tr><td valign="top" align="left"><p>
The <span class="strong"><strong>print rule</strong></span><a name="N113ED" class="indexterm"></a> is used for 
printing output from ASM programs to various buffers or to the code output view. 
</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_PrintRule_Syntax"></a>Syntax</th></tr><tr><td valign="top" align="left"><pre class="programlisting">
PrintRuleAST ::= <span class="token">print</span> <span class="token">(</span> OptBufferAST <a href="def_LogicalTerm.html" title="5.2.1.&nbsp;Logical Term">LogicalTermAST</a> <span class="token">)</span> <span class="token">;</span>
               | <span class="token">println</span> <span class="token">(</span> OptBufferAST <a href="def_LogicalTerm.html" title="5.2.1.&nbsp;Logical Term">LogicalTermAST</a> <span class="token">)</span> <span class="token">;</span>

OptBufferAST ::= $empty   
               | <a href="def_Variable.html" title="5.7.2.&nbsp;Variable">VariableRefAST</a> <span class="token">,</span> 
</pre><p>
The <span class="strong"><strong>print rule</strong></span> contains an optional output buffer and a term to be printed.
</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_PrintRule_Semantics"></a>Semantics</th></tr><tr><td valign="top" align="left"><p>
The <span class="strong"><strong>print rule</strong></span> evaluates its argument <a href="def_Term.html" title="5.1.1.&nbsp;ASM Term">term</a> and 
prints the resulted value to corresponding output buffer or the <span class="emphasis"><em>Code Output View</em></span> 
(if the optional buffer is not specified).
The <span class="strong"><strong>println rule</strong></span> adds a newline character 
to the output string in addition. If the buffer is not specified then the 
</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_PrintRule_Constraints"></a>Constraints</th></tr><tr><td valign="top" align="left"><p>
Prior to calling rule, the output buffer should be initialized 
by a call to native function XXX. 
</p></td></tr></table></div><div class="highlights"><a name="def_PrintRule_Remark"></a><p><b>Remark.&nbsp;</b>
The <span class="strong"><strong>print rule</strong></span> can be used for instance for code generation or 
for printing status messages. 
</p></div><div class="highlights"><a name="def_PrintRule_DefinedIn"></a><p><b>Defined In:&nbsp;</b>
<a href="def_SimpleRule.html" title="4.2.1.&nbsp;Simple Rule">simple rule</a>
</p></div><div class="highlights"><a name="def_PrintRule_SeeAlso"></a><p><b>See Also:&nbsp;</b>
<a href="def_LogRule.html" title="4.2.7.&nbsp;Log Rule">log rule</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_UpdateRule.html">Prev</a>&nbsp;</td><td align="center" width="20%"><a accesskey="u" href="sec_ASMSimpleRules.html">Up</a></td><td align="right" width="40%">&nbsp;<a accesskey="n" href="def_LogRule.html">Next</a></td></tr><tr><td valign="top" align="left" width="40%">4.2.5.&nbsp;Update Rule&nbsp;</td><td align="center" width="20%"><a accesskey="h" href="index.html">Home</a></td><td valign="top" align="right" width="40%">&nbsp;4.2.7.&nbsp;Log Rule</td></tr></table></div></body></html>