1 | <?php |
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2 | |
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3 | /** |
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4 | * Computes a mathematical equation |
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5 | * <pre> |
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6 | * * equation : the equation to compute, it can include normal variables with $foo or special math variables without the dollar sign |
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7 | * * format : output format, see {@link http://php.net/sprintf} for details |
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8 | * * assign : if set, the output is assigned into the given variable name instead of being output |
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9 | * * rest : all math specific variables that you use must be defined, see the example |
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10 | * </pre> |
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11 | * Example : |
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12 | * |
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13 | * <code> |
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14 | * {$c=2} |
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15 | * {math "(a+b)*$c/4" a=3 b=5} |
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16 | * |
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17 | * output is : 4 ( = (3+5)*2/4) |
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18 | * </code> |
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19 | * |
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20 | * This software is provided 'as-is', without any express or implied warranty. |
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21 | * In no event will the authors be held liable for any damages arising from the use of this software. |
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22 | * |
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23 | * @author Jordi Boggiano <j.boggiano@seld.be> |
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24 | * @copyright Copyright (c) 2008, Jordi Boggiano |
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25 | * @license http://dwoo.org/LICENSE Modified BSD License |
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26 | * @link http://dwoo.org/ |
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27 | * @version 1.0.0 |
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28 | * @date 2008-10-23 |
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29 | * @package Dwoo |
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30 | */ |
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31 | function Dwoo_Plugin_math_compile(Dwoo_Compiler $compiler, $equation, $format='', $assign='', array $rest=array()) |
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32 | { |
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33 | /** |
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34 | * Holds the allowed function, characters, operators and constants |
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35 | */ |
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36 | $allowed = array |
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37 | ( |
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38 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
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39 | '+', '-', '/', '*', '.', ' ', '<<', '>>', '%', '&', '^', '|', '~', |
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40 | 'abs(', 'ceil(', 'floor(', 'exp(', 'log10(', |
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41 | 'cos(', 'sin(', 'sqrt(', 'tan(', |
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42 | 'M_PI', 'INF', 'M_E', |
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43 | ); |
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44 | |
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45 | /** |
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46 | * Holds the functions that can accept multiple arguments |
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47 | */ |
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48 | $funcs = array |
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49 | ( |
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50 | 'round(', 'log(', 'pow(', |
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51 | 'max(', 'min(', 'rand(', |
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52 | ); |
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53 | |
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54 | $equation = $equationSrc = str_ireplace(array('pi', 'M_PI()', 'inf', ' e '), array('M_PI', 'M_PI', 'INF', ' M_E '), $equation); |
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55 | |
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56 | $delim = $equation[0]; |
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57 | $open = $delim.'.'; |
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58 | $close = '.'.$delim; |
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59 | $equation = substr($equation, 1, -1); |
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60 | $out = ''; |
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61 | $ptr = 1; |
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62 | $allowcomma = 0; |
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63 | while (strlen($equation) > 0) { |
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64 | $substr = substr($equation, 0, $ptr); |
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65 | if (array_search($substr, $allowed) !== false) { |
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66 | // allowed string |
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67 | $out.=$substr; |
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68 | $equation = substr($equation, $ptr); |
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69 | $ptr = 0; |
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70 | } elseif (array_search($substr, $funcs) !== false) { |
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71 | // allowed func |
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72 | $out.=$substr; |
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73 | $equation = substr($equation, $ptr); |
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74 | $ptr = 0; |
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75 | $allowcomma++; |
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76 | if ($allowcomma === 1) { |
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77 | $allowed[] = ','; |
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78 | } |
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79 | } elseif (isset($rest[$substr])) { |
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80 | // variable |
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81 | $out.=$rest[$substr]; |
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82 | $equation = substr($equation, $ptr); |
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83 | $ptr = 0; |
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84 | } elseif ($substr === $open) { |
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85 | // pre-replaced variable |
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86 | preg_match('#.*\((?:[^()]*?|(?R))\)'.str_replace('.', '\\.', $close).'#', substr($equation, 2), $m); |
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87 | if (empty($m)) { |
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88 | preg_match('#.*?'.str_replace('.', '\\.', $close).'#', substr($equation, 2), $m); |
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89 | } |
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90 | $out.=substr($m[0], 0, -2); |
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91 | $equation = substr($equation, strlen($m[0])+2); |
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92 | $ptr = 0; |
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93 | } elseif ($substr==='(') { |
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94 | // opening parenthesis |
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95 | if ($allowcomma>0) { |
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96 | $allowcomma++; |
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97 | } |
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98 | |
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99 | $out.=$substr; |
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100 | $equation = substr($equation, $ptr); |
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101 | $ptr = 0; |
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102 | } elseif ($substr===')') { |
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103 | // closing parenthesis |
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104 | if ($allowcomma>0) { |
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105 | $allowcomma--; |
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106 | if ($allowcomma===0) { |
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107 | array_pop($allowed); |
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108 | } |
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109 | } |
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110 | |
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111 | $out.=$substr; |
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112 | $equation = substr($equation, $ptr); |
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113 | $ptr = 0; |
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114 | } elseif ($ptr >= strlen($equation)) { |
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115 | // parse error if we've consumed the entire equation without finding anything valid |
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116 | throw new Dwoo_Compilation_Exception($compiler, 'Math : Syntax error or variable undefined in equation '.$equationSrc.' at '.$substr); |
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117 | return; |
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118 | } else { |
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119 | // nothing special, advance |
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120 | $ptr++; |
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121 | } |
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122 | } |
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123 | if ($format !== '\'\'') { |
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124 | $out = 'sprintf('.$format.', '.$out.')'; |
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125 | } |
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126 | if ($assign !== '\'\'') { |
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127 | return '($this->assignInScope('.$out.', '.$assign.'))'; |
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128 | } |
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129 | return '('.$out.')'; |
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130 | } |
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