Help/Language/Literals.html

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  21 <p class="p1"><b>Literals</b></p>
  22 <p class="p2"><br></p>
  23 <p class="p3">Literals are values which have a direct syntactic representation.<span class="Apple-converted-space"> </span></p>
  24 <p class="p3">The following sections describe the types of literals that can be represented.</p>
  25 <p class="p4"><br></p>
  26 <p class="p1"><b>Numbers</b></p>
  27 <p class="p4"><br></p>
  28 <p class="p3">An integer is any series of digits optionally preceeded by a minus sign.</p>
  29 <p class="p3">examples of integers :</p>
  30 <p class="p5"><span class="Apple-tab-span">     </span>-13 <span class="Apple-converted-space">     </span></p>
  31 <p class="p5"><span class="Apple-tab-span">     </span>666 <span class="Apple-converted-space">     </span></p>
  32 <p class="p5"><span class="Apple-tab-span">     </span>2112 <span class="Apple-converted-space">     </span></p>
  33 <p class="p5"><span class="Apple-tab-span">     </span>96</p>
  34 <p class="p4"><br></p>
  35 <p class="p3">A float is one or more decimal digits followed by a decimal point followed by one or more decimal digits.<span class="Apple-converted-space"> </span></p>
  36 <p class="p3">You must have digits on both sides of the decimal point.<span class="Apple-converted-space">  </span>This distinguishes floating point numbers from<span class="Apple-converted-space"> </span></p>
  37 <p class="p3">integer expressions like:</p>
  38 <p class="p4"><br></p>
  39 <p class="p5"><span class="s1"><span class="Apple-tab-span">    </span></span>8.rand</p>
  40 <p class="p4"><span class="Apple-converted-space"> </span></p>
  41 <p class="p3">examples of floats :</p>
  42 <p class="p5"><span class="Apple-tab-span">     </span>0.39 <span class="Apple-converted-space">     </span></p>
  43 <p class="p5"><span class="Apple-tab-span">     </span>98.6 <span class="Apple-converted-space">     </span></p>
  44 <p class="p5"><span class="Apple-tab-span">     </span>1.0 <span class="Apple-converted-space">     </span></p>
  45 <p class="p5"><span class="Apple-tab-span">     </span>-0.5<span class="Apple-converted-space">     </span></p>
  46 <p class="p6"><br></p>
  47 <p class="p3">Exponential notation is also supported.</p>
  48 <p class="p6"><br></p>
  49 <p class="p5"><span class="Apple-tab-span">     </span>1.2e4</p>
  50 <p class="p5"><span class="Apple-tab-span">     </span>1e-4</p>
  51 <p class="p4"><br></p>
  52 <p class="p3">The constant pi can be appended to a number to create floating point constant:</p>
  53 <p class="p4"><br></p>
  54 <p class="p5"><span class="Apple-tab-span">     </span>2pi <span class="Apple-converted-space">   </span></p>
  55 <p class="p5"><span class="Apple-tab-span">     </span>0.5pi</p>
  56 <p class="p5"><span class="Apple-tab-span">     </span>-0.25pi</p>
  57 <p class="p6"><span class="Apple-tab-span">     </span></p>
  58 <p class="p3">Numbers can also be written in radices other than base 10 up to base 36.<span class="Apple-converted-space"> </span></p>
  59 <p class="p3">The radix is specified in base 10 followed by the letter 'r' followed by the value written in</p>
  60 <p class="p3">that radix using characters 0-9,A-Z, or a-z, for digit values from 0 to 35.<span class="Apple-converted-space"> </span></p>
  61 <p class="p3">For example you can write hexidecimal numbers as follows:</p>
  62 <p class="p4"><br></p>
  63 <p class="p5">16rF0</p>
  64 <p class="p5">16rA9FF</p>
  65 <p class="p4"><br></p>
  66 <p class="p3">Binary numbers can be written as follows:</p>
  67 <p class="p6"><br></p>
  68 <p class="p5">2r01101011</p>
  69 <p class="p6"><br></p>
  70 <p class="p3">Floating point values may also be specified in any base:</p>
  71 <p class="p4"><br></p>
  72 <p class="p5">12r4A.A</p>
  73 <p class="p4"><br></p>
  74 <p class="p1"><b>Characters</b></p>
  75 <p class="p4"><br></p>
  76 <p class="p3">Characters are preceeded by a dollar sign:</p>
  77 <p class="p3"><span class="Apple-tab-span">     </span>$A<span class="Apple-converted-space">     </span></p>
  78 <p class="p3"><span class="Apple-tab-span">     </span>$B<span class="Apple-converted-space">     </span></p>
  79 <p class="p3"><span class="Apple-tab-span">     </span>$C<span class="Apple-converted-space">       </span></p>
  80 <p class="p4"><br></p>
  81 <p class="p3">Tab, linefeed, carriage return, and backslash are preceeded by a backslash:</p>
  82 <p class="p5"><span class="Apple-tab-span">     </span>$\t</p>
  83 <p class="p5"><span class="Apple-tab-span">     </span>$\n</p>
  84 <p class="p5"><span class="Apple-tab-span">     </span>$\r</p>
  85 <p class="p5"><span class="Apple-tab-span">     </span>$\\</p>
  86 <p class="p6"><br></p>
  87 <p class="p6"><br></p>
  88 <p class="p1"><b>Symbols</b><span class="s1"><span class="Apple-converted-space"> </span></span></p>
  89 <p class="p4"><br></p>
  90 <p class="p3">A symbol is written as a string enclosed in single quotes.<span class="Apple-converted-space"> </span></p>
  91 <p class="p3">examples of symbols:</p>
  92 <p class="p4"><br></p>
  93 <p class="p5"><span class="Apple-tab-span">     </span>'x'</p>
  94 <p class="p5"><span class="Apple-tab-span">     </span>'aiff'</p>
  95 <p class="p5"><span class="Apple-tab-span">     </span>'BigSwiftyAndAssoc'</p>
  96 <p class="p5"><span class="Apple-tab-span">     </span>'nowhere here' <span class="Apple-converted-space"> </span></p>
  97 <p class="p5"><span class="Apple-tab-span">     </span>'somewhere there'<span class="Apple-converted-space"> </span></p>
  98 <p class="p5"><span class="Apple-tab-span">     </span>'.+o*o+.'</p>
  99 <p class="p6"><span class="Apple-tab-span">     </span></p>
 100 <p class="p3">A symbol consisting of a single word can be written with a preceeding backslash.</p>
 101 <p class="p6"><br></p>
 102 <p class="p5"><span class="Apple-tab-span">     </span>\x</p>
 103 <p class="p5"><span class="Apple-tab-span">     </span>\aiff</p>
 104 <p class="p5"><span class="Apple-tab-span">     </span>\BigSwiftyAndAssoc</p>
 105 <p class="p4"><br></p>
 106 <p class="p1"><b>Strings</b></p>
 107 <p class="p4"><br></p>
 108 <p class="p3">Strings are written in double quotes:</p>
 109 <p class="p4"><br></p>
 110 <p class="p5"><span class="Apple-tab-span">     </span>"This is a string."</p>
 111 <p class="p4"><span class="Apple-tab-span">     </span></p>
 112 <p class="p3">If two or more strings are lexically adjacent, then they combine into a larger string.<span class="Apple-converted-space"> </span></p>
 113 <p class="p4"><br></p>
 114 <p class="p3">example:</p>
 115 <p class="p4"><br></p>
 116 <p class="p5"><span class="Apple-tab-span">     </span>"This" " is " "also a " "string."</p>
 117 <p class="p4"><br></p>
 118 <p class="p3">Strings may span more than one line. If so, then the new line characters become part of the string.</p>
 119 <p class="p3">example:</p>
 120 <p class="p4"><br></p>
 121 <p class="p5">"This</p>
 122 <p class="p5">is<span class="Apple-converted-space"> </span></p>
 123 <p class="p5">also a</p>
 124 <p class="p5">string.</p>
 125 <p class="p5">"</p>
 126 <p class="p4"><span class="Apple-tab-span">     </span></p>
 127 <p class="p1"><b>Identifiers</b><span class="s1"><span class="Apple-converted-space"> </span></span></p>
 128 <p class="p4"><br></p>
 129 <p class="p3">Names of methods and variables begin with a lower case alphabetic character, followed<span class="Apple-converted-space">  </span>by zero or more<span class="Apple-converted-space"> </span></p>
 130 <p class="p3">alphanumeric characters.<span class="Apple-converted-space"> </span></p>
 131 <p class="p4"><br></p>
 132 <p class="p5">var abc, z123, func;</p>
 133 <p class="p6"><br></p>
 134 <p class="p4"><br></p>
 135 <p class="p1"><b>Class Names</b></p>
 136 <p class="p4"><br></p>
 137 <p class="p3">Class names always begin with a capital letter followed<span class="Apple-converted-space">  </span>by zero or more<span class="Apple-converted-space">  </span>alphanumeric characters.</p>
 138 <p class="p4"><br></p>
 139 <p class="p5">Object</p>
 140 <p class="p5">Point</p>
 141 <p class="p5">Synth</p>
 142 <p class="p4"><br></p>
 143 <p class="p4"><br></p>
 144 <p class="p1"><b>Special Values</b></p>
 145 <p class="p4"><br></p>
 146 <p class="p3">The singular instances of the classes True, False and Nil are written as the<span class="Apple-converted-space"> </span></p>
 147 <p class="p3">words true, false, nil and inf.</p>
 148 <p class="p4"><br></p>
 149 <p class="p5">x = true;</p>
 150 <p class="p5">y = false;</p>
 151 <p class="p5">z = nil;</p>
 152 <p class="p6"><br></p>
 153 <p class="p1"><b>Literal Arrays</b></p>
 154 <p class="p4"><br></p>
 155 <p class="p3">Arrays of literals are created at compile time and are written with a # preceeding the array as follows:</p>
 156 <p class="p4"><br></p>
 157 <p class="p5">#[1, 2, 'abc', "def", 4]</p>
 158 <p class="p6"><br></p>
 159 <p class="p3">Literal Arrays must be used as is and may not be altered at run time.</p>
 160 <p class="p4"><br></p>
 161 <p class="p3">In literal Arrays names are interpreted as symbols. This is not the case in regular Arrays, where they are interpreted as variable names:</p>
 162 <p class="p4"><br></p>
 163 <p class="p5">#[foo, bar]<span class="Apple-tab-span">  </span>// this is legal; an Array of Symbols</p>
 164 <p class="p5">[foo, bar]<span class="Apple-tab-span">   </span>// this is only legal if foo and bar have been declared as variables</p>
 165 <p class="p4"><br></p>
 166 <p class="p3">Arrays and other collections may also be created dynamically which is explained in Collections.help.</p>
 167 <p class="p3">Using a literal Array is faster than building an array dynamically every time you need it.</p>
 168 <p class="p6"><br></p>
 169 <p class="p3">When nesting literal arrays, only the outermost literal array needs the '#' character.</p>
 170 <p class="p6"><br></p>
 171 <p class="p5">#[[1, 2, 3], [4, 5, 6]]</p>
 172 <p class="p4"><br></p>
 173 <p class="p3">Literal Arrays can be useful for things such as tables of constants, for example note names:</p>
 174 <p class="p4"><br></p>
 175 <p class="p5">(</p>
 176 <p class="p5">// build a table of note names</p>
 177 <p class="p5">var table = ();</p>
 178 <p class="p5">value {</p>
 179 <p class="p5"><span class="Apple-tab-span">     </span>var semitones = [0, 2, 4, 5, 7, 9, 11];</p>
 180 <p class="p5"><span class="Apple-tab-span">     </span>var naturalNoteNames = ["c", "d", "e", "f", "g", "a", "b"];</p>
 181 <p class="p6"><br></p>
 182 <p class="p5"><span class="Apple-tab-span">     </span>(0..9).do {|o|</p>
 183 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>naturalNoteNames.do {|c, i|</p>
 184 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>var n = (o + 1) * 12 + semitones[i];</p>
 185 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>table[(c ++ o).asSymbol] = n;</p>
 186 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>table[(c ++ "s"<span class="Apple-converted-space">  </span>++ o).asSymbol] = n + 1;</p>
 187 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>table[(c ++ "ss" ++ o).asSymbol] = n + 2;</p>
 188 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>table[(c ++ "b"<span class="Apple-converted-space">  </span>++ o).asSymbol] = n - 1;</p>
 189 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span>table[(c ++ "bb" ++ o).asSymbol] = n - 2;</p>
 190 <p class="p5"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>};</p>
 191 <p class="p5"><span class="Apple-tab-span">     </span>};</p>
 192 <p class="p5">};</p>
 193 <p class="p6"><br></p>
 194 <p class="p5">// translate note names to midi keys</p>
 195 <p class="p5">table.atAll(#[c4, e4, gs4, c5, e5, gs5, c6])</p>
 196 <p class="p5">)</p>
 197 <p class="p4"><br></p>
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