Help/Core/Symbol.html

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  42 <p class="p1"><span class="s1"><b>Symbol<span class="Apple-tab-span">   </span></b></span><b><span class="Apple-tab-span">      </span><span class="Apple-tab-span">    </span>unique name</b></p>
  43 <p class="p2"><br></p>
  44 <p class="p1"><b>superclass: </b><a href="Object.html"><span class="s2"><b>Object</b></span></a></p>
  45 <p class="p2"><br></p>
  46 <p class="p1">A Symbol is a name that is guaranteed to be <b>unique</b>. They can be used to represent</p>
  47 <p class="p1">symbolic constant values, Dictionary keys, etc.</p>
  48 <p class="p2"><br></p>
  49 <p class="p1">Symbols are represented syntactically as literals which are described in [<a href="../Language/Literals.html"><span class="s2">Literals</span></a>]</p>
  50 <p class="p2"><br></p>
  51 <p class="p2"><br></p>
  52 <p class="p3"><b>Creating a Symbol</b></p>
  53 <p class="p2"><br></p>
  54 <p class="p1"><span class="Apple-tab-span">     </span>A symbol can be written by surrounding characters by single quotes (may include whitespace):</p>
  55 <p class="p2"><br></p>
  56 <p class="p4"><span class="Apple-tab-span">     </span>'foo bar'</p>
  57 <p class="p2"><br></p>
  58 <p class="p1"><span class="Apple-tab-span">     </span>Or by a preceeding backslash (then it may not include whitespace):</p>
  59 <p class="p2"><br></p>
  60 <p class="p4"><span class="Apple-tab-span">     </span>\foo</p>
  61 <p class="p2"><br></p>
  62 <p class="p1"><span class="Apple-tab-span">     </span>A String can be converted into a symbol:</p>
  63 <p class="p2"><br></p>
  64 <p class="p5"><span class="Apple-tab-span">     </span><span class="s3">"arbeit"</span>.scramble.asSymbol;</p>
  65 <p class="p2"><br></p>
  66 <p class="p2"><br></p>
  67 <p class="p3"><b>Testing</b></p>
  68 <p class="p6"><br></p>
  69 <p class="p7"><b><span class="Apple-tab-span">  </span>isClassName / isMetaClassName</b></p>
  70 <p class="p6"><span class="Apple-tab-span">     </span></p>
  71 <p class="p7"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>Answer whether the symbol can be a class name / meta class name. This does not say if the class exists.</p>
  72 <p class="p6"><span class="Apple-tab-span">     </span></p>
  73 <p class="p8"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="s4">\Array</span>.isClassName;</p>
  74 <p class="p8"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="s4">\Bauxite</span>.isClassName;</p>
  75 <p class="p8"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="s5">\Meta_Array</span>.isMetaClassName;</p>
  76 <p class="p6"><span class="Apple-tab-span">     </span></p>
  77 <p class="p7"><span class="Apple-tab-span">     </span><b>isSetter</b></p>
  78 <p class="p6"><span class="Apple-tab-span">     </span></p>
  79 <p class="p7"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>Answer whether the symbol has a trailing underscore.</p>
  80 <p class="p6"><span class="Apple-tab-span">     </span></p>
  81 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></span><span class="s4">'_action'</span>.isSetter;</p>
  82 <p class="p9"><span class="Apple-tab-span">     </span></p>
  83 <p class="p7"><span class="s7"><span class="Apple-tab-span">    </span></span><b>isPrimitiveName</b></p>
  84 <p class="p6"><span class="Apple-tab-span">     </span></p>
  85 <p class="p7"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>Answer whether the symbol is a valid primitive name</p>
  86 <p class="p6"><span class="Apple-tab-span">     </span></p>
  87 <p class="p10"><span class="s8"><span class="Apple-tab-span">   </span><span class="Apple-tab-span">    </span></span>'_SymbolIsClassName'<span class="s9">.isPrimitiveName;</span></p>
  88 <p class="p6"><br></p>
  89 <p class="p6"><br></p>
  90 <p class="p11"><b>Conversion</b></p>
  91 <p class="p6"><br></p>
  92 <p class="p7"><b><span class="Apple-tab-span">  </span>asString</b></p>
  93 <p class="p6"><span class="Apple-tab-span">     </span></p>
  94 <p class="p7"><span class="Apple-tab-span">     </span>Convert to a <a href="../Collections/String.html"><span class="s2">String</span></a></p>
  95 <p class="p6"><span class="Apple-tab-span">     </span></p>
  96 <p class="p7"><span class="Apple-tab-span">     </span><b>asInteger</b></p>
  97 <p class="p6"><span class="Apple-tab-span">     </span></p>
  98 <p class="p7"><span class="Apple-tab-span">     </span>Convert to an <a href="../Math/Integer.html"><span class="s2">Integer</span></a></p>
  99 <p class="p6"><span class="Apple-tab-span">     </span></p>
 100 <p class="p7"><span class="Apple-tab-span">     </span><b>asClass</b></p>
 101 <p class="p6"><span class="Apple-tab-span">     </span></p>
 102 <p class="p7"><span class="Apple-tab-span">     </span>Answer the <a href="Kernel/Class.html"><span class="s2">Class</span></a> named by the receiver.</p>
 103 <p class="p6"><span class="Apple-tab-span">     </span></p>
 104 <p class="p7"><span class="Apple-tab-span">     </span><b>asSetter</b></p>
 105 <p class="p6"><span class="Apple-tab-span">     </span></p>
 106 <p class="p7"><span class="Apple-tab-span">     </span>Return a symbol with a trailing underscore added.</p>
 107 <p class="p6"><span class="Apple-tab-span">     </span></p>
 108 <p class="p7"><span class="Apple-tab-span">     </span><b>asGetter</b></p>
 109 <p class="p6"><span class="Apple-tab-span">     </span></p>
 110 <p class="p7"><span class="Apple-tab-span">     </span>Return a symbol with a trailing underscore removed.</p>
 111 <p class="p6"><span class="Apple-tab-span">     </span></p>
 112 <p class="p7"><span class="Apple-tab-span">     </span><b>ascii</b></p>
 113 <p class="p6"><span class="Apple-tab-span">     </span></p>
 114 <p class="p7"><span class="Apple-tab-span">     </span>return the ascii codes as an array</p>
 115 <p class="p6"><span class="Apple-tab-span">     </span></p>
 116 <p class="p7"><span class="Apple-tab-span">     </span><b>asSpec</b></p>
 117 <p class="p6"><span class="Apple-tab-span">     </span></p>
 118 <p class="p7"><span class="Apple-tab-span">     </span>Convert to a <a href="../Control/ControlSpec.html"><span class="s2">ControlSpec</span></a></p>
 119 <p class="p6"><br></p>
 120 <p class="p7"><span class="Apple-tab-span">     </span><b>asTuning</b></p>
 121 <p class="p6"><span class="Apple-tab-span">     </span></p>
 122 <p class="p7"><span class="Apple-tab-span">     </span>Convert to a <a href="../Collections/Tuning.html"><span class="s2">Tuning</span></a></p>
 123 <p class="p6"><span class="Apple-tab-span">     </span></p>
 124 <p class="p7"><span class="Apple-tab-span">     </span><b>asScale</b></p>
 125 <p class="p6"><span class="Apple-tab-span">     </span></p>
 126 <p class="p7"><span class="Apple-tab-span">     </span>Convert to a <a href="../Collections/Scale.html"><span class="s2">Scale</span></a></p>
 127 <p class="p6"><span class="Apple-tab-span">     </span></p>
 128 <p class="p6"><br></p>
 129 <p class="p11"><b>Environments</b></p>
 130 <p class="p12"><br></p>
 131 <p class="p7">Symbols are used as keys to look up objects in dictionaries and environments, but also in arrays.<span class="Apple-converted-space"> </span></p>
 132 <p class="p13"><span class="s9">See <a href="../Collections/IdentityDictionary.html"><span class="s6">IdentityDictionary</span></a>, <a href="../Collections/Environment.html"><span class="s6">Environment</span></a>, <a href="../Collections/Event.html"><span class="s6">Event</span></a></span></p>
 133 <p class="p14"><br></p>
 134 <p class="p8"><span class="Apple-tab-span">     </span>a = ();</p>
 135 <p class="p8"><span class="Apple-tab-span">     </span>a.put(<span class="s4">\commune</span>, 1871);</p>
 136 <p class="p15"><span class="s9"><span class="Apple-tab-span">   </span>a.at(</span>\commune<span class="s9">);</span></p>
 137 <p class="p6"><br></p>
 138 <p class="p7"><span class="Apple-tab-span">     </span><b>envirPut(aValue)</b></p>
 139 <p class="p6"><span class="Apple-tab-span">     </span></p>
 140 <p class="p7"><span class="Apple-tab-span">     </span>put a value to the current environment using receiver as key</p>
 141 <p class="p6"><span class="Apple-tab-span">     </span></p>
 142 <p class="p6"><span class="Apple-tab-span">     </span></p>
 143 <p class="p7"><span class="Apple-tab-span">     </span><b>envirGet</b></p>
 144 <p class="p6"><span class="Apple-tab-span">     </span></p>
 145 <p class="p7"><span class="Apple-tab-span">     </span>return a value from the current environment using receiver as key</p>
 146 <p class="p6"><span class="Apple-tab-span">     </span></p>
 147 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span></span><span class="s4">\foo</span>.envirPut(100);</p>
 148 <p class="p8"><span class="Apple-tab-span">     </span><span class="s4">\foo</span>.envirGet;</p>
 149 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span></span><span class="s4">\foo</span>.envirPut(<span class="s10">nil</span>);</p>
 150 <p class="p6"><span class="Apple-tab-span">     </span></p>
 151 <p class="p11"><b>Math</b></p>
 152 <p class="p6"><br></p>
 153 <p class="p7"><span class="Apple-tab-span">     </span>Symbols respond to all unary and binary math operations by returning themselves. The result of any math operation between a Number or other math object and a Symbol is to return the Symbol. This allows for example operations on lists of notes which contain 'rest's to preserve the rests.</p>
 154 <p class="p16"><span class="Apple-tab-span">    </span></p>
 155 <p class="p8"><span class="s5"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></span><span class="s10">Pseq</span>([1, 3, <span class="s4">\rest</span>, 2, 4] + 8);</p>
 156 <p class="p6"><span class="Apple-tab-span">     </span></p>
 157 <p class="p7"><span class="Apple-tab-span">     </span><b>applyTo(firstArg ... args)</b></p>
 158 <p class="p6"><span class="Apple-tab-span">     </span></p>
 159 <p class="p7"><span class="Apple-tab-span">     </span>Use the symbol as a method selector and perform the message on <b>firstArg</b>, with <b>args</b> as arguments. This is used for mixing functions with method selectors (see also: <a href="Kernel/Function.html"><span class="s2">Function</span></a>).</p>
 160 <p class="p6"><span class="Apple-tab-span">     </span></p>
 161 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></span><span class="s4">'%'</span>.applyTo(2553, 345<span class="s6">);</span></p>
 162 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></span>[<span class="s4">'+'</span>, <span class="s4">'-'</span>, <span class="s4">'*'</span>, { <span class="s10">|a, b|</span> a.rand + b.rand } ].choose.applyTo(2, 3);</p>
 163 <p class="p9"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span></p>
 164 <p class="p9"><span class="Apple-tab-span">     </span></p>
 165 <p class="p6"><span class="Apple-tab-span">     </span></p>
 166 <p class="p11"><b>Synthesis</b></p>
 167 <p class="p6"><br></p>
 168 <p class="p7"><span class="Apple-tab-span">     </span>Inside SynthDefs and UGen functions, symbols can be used to conventiently specify control inputs of different rates and with lags (see:<span class="Apple-converted-space">  </span><a href="../UGens/Synth control/NamedControl.html"><span class="s2">NamedControl</span></a>, <a href="../UGens/Synth control/ControlName.html"><span class="s2">ControlName</span></a><span class="s2">, </span>and<span class="s2"> <a href="../UGens/Synth control/Control.html"><span class="s11">Control</span></a></span>).</p>
 169 <p class="p6"><span class="Apple-tab-span">     </span></p>
 170 <p class="p6"><span class="Apple-tab-span">     </span></p>
 171 <p class="p7"><span class="Apple-tab-span">     </span><b>kr(val, lag)</b></p>
 172 <p class="p6"><span class="Apple-tab-span">     </span></p>
 173 <p class="p7"><span class="Apple-tab-span">     </span>Return a control rate <a href="../UGens/Synth control/NamedControl.html"><span class="s2">NamedControl</span></a> input with a default value (<b>val</b>), and if supplied, with a <b>lag</b>. If val is an array, the control will be multichannel.</p>
 174 <p class="p6"><span class="Apple-tab-span">     </span></p>
 175 <p class="p8"><span class="Apple-tab-span">     </span>a = { <span class="s10">SinOsc</span>.ar(<span class="s5">\freq</span>.kr(440, 1.2)) }.play;</p>
 176 <p class="p8"><span class="Apple-tab-span">     </span>a.set(<span class="s5">\freq</span>, 330);</p>
 177 <p class="p8"><span class="Apple-tab-span">     </span>a.release;</p>
 178 <p class="p8"><span class="s6"><span class="Apple-tab-span">    </span></span>a = { <span class="s12">SinOsc</span>.ar(<span class="s5">\freq</span>.kr([440, 460], 1.2)) }.play;</p>
 179 <p class="p8"><span class="Apple-tab-span">     </span>a.setn(<span class="s5">\freq</span>, [330, 367]);</p>
 180 <p class="p8"><span class="Apple-tab-span">     </span>a.release;</p>
 181 <p class="p9"><span class="Apple-tab-span">     </span></p>
 182 <p class="p7"><span class="s7"><span class="Apple-tab-span">    </span></span><b>ar(val, lag)</b></p>
 183 <p class="p6"><span class="Apple-tab-span">     </span></p>
 184 <p class="p7"><span class="Apple-tab-span">     </span>Return an audio rate <a href="../UGens/Synth control/NamedControl.html"><span class="s2">NamedControl</span></a><span class="s2"> </span>input with a default value (<b>val</b>), and if supplied, with a <b>lag</b>. If val is an array, the control will be multichannel.</p>
 185 <p class="p12"><br></p>
 186 <p class="p7"><span class="Apple-tab-span">     </span><b>ir(val)</b></p>
 187 <p class="p6"><span class="Apple-tab-span">     </span></p>
 188 <p class="p7"><span class="Apple-tab-span">     </span>Return an intitalization rate <a href="../UGens/Synth control/NamedControl.html"><span class="s2">NamedControl</span></a><span class="s2"> </span>input with a default value (<b>val</b>). If val is an array, the control will be multichannel.</p>
 189 <p class="p6"><span class="s7"><span class="Apple-tab-span">    </span></span><span class="Apple-tab-span">     </span></p>
 190 <p class="p7"><span class="Apple-tab-span">     </span><b>tr(val)</b></p>
 191 <p class="p6"><span class="Apple-tab-span">     </span></p>
 192 <p class="p7"><span class="Apple-tab-span">     </span>Return a TrigControl input with a default value (<b>val</b>). If val is an array, the control will be multichannel.</p>
 193 <p class="p6"><span class="Apple-tab-span">     </span></p>
 194 <p class="p8"><span class="Apple-tab-span">     </span>a = { <span class="s10">Ringz</span>.ar(<span class="s10">T2A</span>.ar(<span class="s5">\trig</span>.tr), <span class="s5">\freq</span>.kr(500, 1), 0.8) }.play;</p>
 195 <p class="p8"><span class="Apple-tab-span">     </span>a.set(<span class="s5">\freq</span>, 330, <span class="s5">\trig</span>, 1);</p>
 196 <p class="p8"><span class="Apple-tab-span">     </span>a.set(<span class="s5">\freq</span>, 830, <span class="s5">\trig</span>, 1);</p>
 197 <p class="p8"><span class="Apple-tab-span">     </span>a.release;</p>
 198 <p class="p9"><br></p>
 199 <p class="p9"><span class="Apple-tab-span">     </span></p>
 200 </body>
 201 </html>