Help/Core/Kernel/FunctionList.html

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
   2 <html>
   3 <head>
   4 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
   5 <meta http-equiv="Content-Style-Type" content="text/css">
   6 <title></title>
   7 <meta name="Generator" content="Cocoa HTML Writer">
   8 <meta name="CocoaVersion" content="949.43">
   9 <style type="text/css">
  10 p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica}
  11 p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px}
  12 p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Monaco; min-height: 12.0px}
  13 p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Monaco; color: #bf0000}
  14 p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Monaco; color: #000000; min-height: 12.0px}
  15 p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Monaco; color: #000000}
  16 p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Monaco; color: #606060}
  17 span.s1 {font: 18.0px Helvetica}
  18 span.s2 {color: #0024f8}
  19 span.s3 {color: #0000bf}
  20 span.s4 {color: #606060}
  21 span.s5 {color: #000000}
  22 span.Apple-tab-span {white-space:pre}
  23 </style>
  24 </head>
  25 <body>
  26 <p class="p1"><span class="s1"><b>FunctionList<span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></b></span><b>multiple function</b></p>
  27 <p class="p2"><br></p>
  28 <p class="p1"><b>superclass: AbstractFunction</b></p>
  29 <p class="p3"><br></p>
  30 <p class="p3"><br></p>
  31 <p class="p1">A <b>FunctionList</b> is a function that composes multiple functions into one. This allows allow to deal transparently with several functions as if they were one and to append new functions at a later point. The functions are evaluated in the order they have in the FunctionList's array, which is by default the order in which they have been added to it.</p>
  32 <p class="p2"><br></p>
  33 <p class="p1">See the <a href="../../Language/Functions.html"><span class="s2">Functions</span></a> help file for a basic introduction.</p>
  34 <p class="p2"><br></p>
  35 <p class="p1"><b>*new(functions)</b><span class="Apple-converted-space"> </span></p>
  36 <p class="p1"><span class="Apple-tab-span">     </span>create a new instance. <i>functions</i> is an array of functions or objects</p>
  37 <p class="p2"><br></p>
  38 <p class="p1"><b>array</b><span class="Apple-tab-span"> </span>return the FunctionList's array. New functions can be added to the array dierctly, e.g.</p>
  39 <p class="p1"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>x = FunctionList(...some functions);<span class="Apple-converted-space">  </span>x.array = x.array.insert(2, aFunction);</p>
  40 <p class="p2"><br></p>
  41 <p class="p1"><b>array_(array)</b><span class="Apple-tab-span"> </span>set the array of the FunctionList.</p>
  42 <p class="p2"><br></p>
  43 <p class="p2"><br></p>
  44 <p class="p1"><b>addFunc(function, function ..)</b><span class="Apple-converted-space"> </span></p>
  45 <p class="p1"><span class="Apple-tab-span">     </span>This message is used to be able to add to <b>an Object</b>, to a <b>Function</b>, or to a <b>FunctionList</b>.</p>
  46 <p class="p1"><span class="Apple-tab-span">     </span>nil.addFunc returns a function, if only one function is passed in the argument.</p>
  47 <p class="p1"><span class="Apple-tab-span">     </span>function.addFunc then returns a FunctionList.<span class="Apple-converted-space"> </span></p>
  48 <p class="p2"><br></p>
  49 <p class="p1"><b>removeFunc(function)</b>, remove a function from the list.<span class="Apple-converted-space"> </span></p>
  50 <p class="p1"><span class="Apple-tab-span">     </span>returns <b>the last function</b> when only one function is left.</p>
  51 <p class="p1"><span class="Apple-tab-span">     </span>returns <b>nil</b> when the last function was removed.</p>
  52 <p class="p2"><br></p>
  53 <p class="p1">addFunc and removeFunc are implemented for <b>Nil</b>, <b>Object</b> and <b>FunctionList</b></p>
  54 <p class="p2"><br></p>
  55 <p class="p1"><span class="Apple-tab-span">     </span>nil.addFunc(f): <span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>returns f</p>
  56 <p class="p1"><span class="Apple-tab-span">     </span>obj.addFunc(f): <span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>returns FunctionList([obj, f])</p>
  57 <p class="p2"><br></p>
  58 <p class="p1"><span class="Apple-tab-span">     </span>nil.removeFunc(f)<span class="Apple-tab-span">   </span><span class="Apple-tab-span">    </span>returns nil</p>
  59 <p class="p1"><span class="Apple-tab-span">     </span>obj.removeFunc(f)<span class="Apple-tab-span">   </span><span class="Apple-tab-span">    </span>returns nil, if f === obj, else obj is returned</p>
  60 <p class="p2"><br></p>
  61 <p class="p3"><br></p>
  62 <p class="p3"><br></p>
  63 <p class="p4">// example</p>
  64 <p class="p5"><br></p>
  65 <p class="p6">a = <span class="s3">nil</span>;</p>
  66 <p class="p6">a = a.addFunc { <span class="s3">|x="", y=""|</span> <span class="s4">"this % is an % example\n"</span>.postf(x, y); 1 };</p>
  67 <p class="p6">a.postln;</p>
  68 <p class="p6">a = a.addFunc { <span class="s3">|x="", y=""|</span> <span class="s4">"there is no % that is %\n"</span>.postf(x, y); 2 };</p>
  69 <p class="p6">a.value;</p>
  70 <p class="p7"><span class="s5">a.value(</span>"text"<span class="s5">, </span>"extraordinary well written"<span class="s5">)</span></p>
  71 <p class="p6">a.valueArray([<span class="s4">"x"</span>, <span class="s4">"y"</span>]);</p>
  72 <p class="p5"><br></p>
  73 <p class="p4">// Function:do vs FunctionList:do (same)</p>
  74 <p class="p6">a.do { <span class="s3">|x|</span> x.value };</p>
  75 <p class="p6">{ 4 }.do { <span class="s3">|x|</span> x.value.postln }</p>
  76 <p class="p5"><br></p>
  77 <p class="p6">(</p>
  78 <p class="p6">().use {</p>
  79 <p class="p6"><span class="Apple-tab-span">     </span>~x = <span class="s4">"array"</span>;</p>
  80 <p class="p7"><span class="s5"><span class="Apple-tab-span">    </span>~y = </span>"ominous"<span class="s5">;</span></p>
  81 <p class="p6"><span class="Apple-tab-span">     </span>a.valueEnvir;</p>
  82 <p class="p6"><span class="Apple-tab-span">     </span>a.valueEnvir(<span class="s4">"list"</span>);</p>
  83 <p class="p6">}</p>
  84 <p class="p6">)</p>
  85 <p class="p5"><br></p>
  86 <p class="p5"><br></p>
  87 <p class="p4">// removing a function</p>
  88 <p class="p6">x = { <span class="s4">"removal test"</span>.postln };</p>
  89 <p class="p6">a.addFunc(x);</p>
  90 <p class="p6">a.value;</p>
  91 <p class="p6">a = a.removeFunc(x);</p>
  92 <p class="p6">a.value;</p>
  93 <p class="p5"><br></p>
  94 <p class="p4">// mathematics</p>
  95 <p class="p6">a = <span class="s3">nil</span>;</p>
  96 <p class="p6">a = a.addFunc({ 1.0.rand }).addFunc({ [0, 1].choose });</p>
  97 <p class="p6">a = a.squared.linexp(0, 1, 1.0, 500);</p>
  98 <p class="p5"><br></p>
  99 <p class="p6">a.value;</p>
 100 <p class="p5"><br></p>
 101 <p class="p5"><br></p>
 102 <p class="p4">// compatibility with function multichannel expansion</p>
 103 <p class="p6">a = <span class="s3">nil</span>;</p>
 104 <p class="p6">a = a.addFunc { <span class="s3">|x=0|</span> if(x &gt; 0) { 7 } { 1000.rand } };</p>
 105 <p class="p6">a = a.addFunc { <span class="s3">|x=0|</span> if(x &lt; 0) { 17 } { -1000.rand } };</p>
 106 <p class="p6">a.value</p>
 107 <p class="p5"><br></p>
 108 <p class="p6">a = a.flop;</p>
 109 <p class="p6">a.value</p>
 110 <p class="p6">a.value([-1, 1])</p>
 111 <p class="p5"><br></p>
 112 <p class="p5"><br></p>
 113 <p class="p5"><br></p>
 114 <p class="p4">// typical usage in a Document action</p>
 115 <p class="p4">// see also SCView: addAction example.</p>
 116 <p class="p5"><br></p>
 117 <p class="p6">d = <span class="s3">Document</span>.current;</p>
 118 <p class="p6">d.keyDownAction = { <span class="s4">"You touched the keyboard."</span>.postln };</p>
 119 <p class="p5"><br></p>
 120 <p class="p6">d.keyDownAction = d.keyDownAction.addFunc {:x, x&lt;-(1..), :: <span class="s4">"already % times\n\n"</span>.postf(x) };</p>
 121 <p class="p5"><br></p>
 122 <p class="p5"><br></p>
 123 <p class="p6">d.keyDownAction = <span class="s3">nil</span>;</p>
 124 <p class="p5"><br></p>
 125 <p class="p4">// even if you don't know if there is already an action defined</p>
 126 <p class="p4">// one can add one.</p>
 127 <p class="p5"><br></p>
 128 <p class="p6">(</p>
 129 <p class="p6">d.keyDownAction = <span class="s3">nil</span>;</p>
 130 <p class="p6">d.keyDownAction = d.keyDownAction.addFunc {:x, x&lt;-(1..), :: <span class="s4">"already % times\n\n"</span>.postf(x) };</p>
 131 <p class="p5"><br></p>
 132 <p class="p6">);</p>
 133 <p class="p5"><br></p>
 134 <p class="p6">d.keyDownAction = <span class="s3">nil</span>;</p>
 135 <p class="p5"><br></p>
 136 <p class="p5"><br></p>
 137 <p class="p5"><br></p>
 138 <p class="p5"><br></p>
 139 </body>
 140 </html>