Angelscript/docs/manual/doc_script_anonfunc.html

135 lines
5.7 KiB
HTML
Raw Permalink Normal View History

2021-04-12 18:25:02 +00:00
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.18"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>AngelScript: Anonymous functions</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtreedata.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/searchdata.js"></script>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
$(document).ready(function() { init_search(); });
/* @license-end */
</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectlogo"><img alt="Logo" src="aslogo_small.png"/></td>
<td id="projectalign" style="padding-left: 0.5em;">
<div id="projectname">AngelScript
</div>
</td>
<td> <div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.18 -->
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
var searchBox = new SearchBox("searchBox", "search",false,'Search');
/* @license-end */
</script>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
$(document).ready(function(){initNavTree('doc_script_anonfunc.html',''); initResizable(); });
/* @license-end */
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
</div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<div class="PageDoc"><div class="header">
<div class="headertitle">
<div class="title">Anonymous functions </div> </div>
</div><!--header-->
<div class="contents">
<div class="textblock"><p>Anonymous functions, or lambdas as they are sometimes called, are functions that are declared locally for use with <a class="el" href="doc_datatypes_funcptr.html">function handles</a>.</p>
<p>The following is a quick demonstration on how to use anonymous functions.</p>
<pre>
funcdef bool CMP(int first, int second);</pre><pre> void main()
{
int valueA = 1, valueB = 2;</pre><pre> bool result1 = func(valueA, valueB, function(a,b){ return a == b; });
bool result2 = func(valueA, valueB, function(a,b){ return a != b; });
}</pre><pre> bool func(int a, int b, CMP @f)
{
return f(a,b);
}
</pre><p>The anonymous function takes on the signature of the function handle it is assigned to, so the type of the arguments and the return type doesn't have to be explicitly declared.</p>
<p>It is not yet possible for anonymous functions to access variables declared in the same scope as the function, i.e. they cannot be used as closures.</p>
<p>If there are multiple matching uses for the anonymous function it will be necessary to explicitly inform the parameter types, so the ambiguity can be resolved.</p>
<pre>
funcdef void A(int);
funcdef void B(float);
void func(A@) {}
void func(B@) {}</pre><pre> void main()
{
// Explicitly specify the type to tell the compiler that A is wanted
func(function(int a) {});
}
</pre> </div></div><!-- contents -->
</div><!-- PageDoc -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="footer">Generated on Sat Dec 5 2020 23:20:24 for AngelScript by
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.18 </li>
</ul>
</div>
</body>
</html>