1 | import { factory } from '../utils/factory';
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2 | import { extend, hasOwnProperty } from '../utils/object';
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3 | import { getSafeProperty, setSafeProperty } from '../utils/customs';
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4 | var name = 'Parser';
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5 | var dependencies = ['parse'];
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6 | export var createParserClass = /* #__PURE__ */factory(name, dependencies, function (_ref) {
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7 | var parse = _ref.parse;
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8 |
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9 | /**
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10 | * @constructor Parser
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11 | * Parser contains methods to evaluate or parse expressions, and has a number
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12 | * of convenience methods to get, set, and remove variables from memory. Parser
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13 | * keeps a scope containing variables in memory, which is used for all
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14 | * evaluations.
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15 | *
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16 | * Methods:
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17 | * const result = parser.evaluate(expr) // evaluate an expression
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18 | * const value = parser.get(name) // retrieve a variable from the parser
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19 | * const values = parser.getAll() // retrieve all defined variables
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20 | * parser.set(name, value) // set a variable in the parser
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21 | * parser.remove(name) // clear a variable from the
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22 | * // parsers scope
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23 | * parser.clear() // clear the parsers scope
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24 | *
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25 | * Example usage:
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26 | * const parser = new Parser()
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27 | * // Note: there is a convenience method which can be used instead:
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28 | * // const parser = new math.parser()
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29 | *
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30 | * // evaluate expressions
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31 | * parser.evaluate('sqrt(3^2 + 4^2)') // 5
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32 | * parser.evaluate('sqrt(-4)') // 2i
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33 | * parser.evaluate('2 inch in cm') // 5.08 cm
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34 | * parser.evaluate('cos(45 deg)') // 0.7071067811865476
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35 | *
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36 | * // define variables and functions
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37 | * parser.evaluate('x = 7 / 2') // 3.5
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38 | * parser.evaluate('x + 3') // 6.5
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39 | * parser.evaluate('function f(x, y) = x^y') // f(x, y)
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40 | * parser.evaluate('f(2, 3)') // 8
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41 | *
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42 | * // get and set variables and functions
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43 | * const x = parser.get('x') // 7
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44 | * const f = parser.get('f') // function
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45 | * const g = f(3, 2) // 9
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46 | * parser.set('h', 500)
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47 | * const i = parser.evaluate('h / 2') // 250
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48 | * parser.set('hello', function (name) {
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49 | * return 'hello, ' + name + '!'
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50 | * })
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51 | * parser.evaluate('hello("user")') // "hello, user!"
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52 | *
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53 | * // clear defined functions and variables
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54 | * parser.clear()
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55 | *
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56 | */
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57 | function Parser() {
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58 | if (!(this instanceof Parser)) {
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59 | throw new SyntaxError('Constructor must be called with the new operator');
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60 | }
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61 |
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62 | this.scope = {};
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63 | }
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64 | /**
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65 | * Attach type information
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66 | */
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67 |
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68 |
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69 | Parser.prototype.type = 'Parser';
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70 | Parser.prototype.isParser = true;
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71 | /**
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72 | * Parse and evaluate the given expression
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73 | * @param {string} expr A string containing an expression, for example "2+3"
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74 | * @return {*} result The result, or undefined when the expression was empty
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75 | * @throws {Error}
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76 | */
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77 |
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78 | Parser.prototype.evaluate = function (expr) {
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79 | // TODO: validate arguments
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80 | return parse(expr).compile().evaluate(this.scope);
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81 | };
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82 | /**
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83 | * Get a variable (a function or variable) by name from the parsers scope.
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84 | * Returns undefined when not found
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85 | * @param {string} name
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86 | * @return {* | undefined} value
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87 | */
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88 |
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89 |
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90 | Parser.prototype.get = function (name) {
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91 | // TODO: validate arguments
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92 | return name in this.scope ? getSafeProperty(this.scope, name) : undefined;
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93 | };
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94 | /**
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95 | * Get a map with all defined variables
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96 | * @return {Object} values
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97 | */
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98 |
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99 |
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100 | Parser.prototype.getAll = function () {
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101 | return extend({}, this.scope);
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102 | };
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103 | /**
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104 | * Set a symbol (a function or variable) by name from the parsers scope.
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105 | * @param {string} name
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106 | * @param {* | undefined} value
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107 | */
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108 |
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109 |
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110 | Parser.prototype.set = function (name, value) {
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111 | // TODO: validate arguments
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112 | return setSafeProperty(this.scope, name, value);
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113 | };
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114 | /**
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115 | * Remove a variable from the parsers scope
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116 | * @param {string} name
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117 | */
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118 |
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119 |
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120 | Parser.prototype.remove = function (name) {
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121 | // TODO: validate arguments
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122 | delete this.scope[name];
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123 | };
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124 | /**
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125 | * Clear the scope with variables and functions
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126 | */
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127 |
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128 |
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129 | Parser.prototype.clear = function () {
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130 | for (var _name in this.scope) {
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131 | if (hasOwnProperty(this.scope, _name)) {
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132 | delete this.scope[_name];
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133 | }
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134 | }
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135 | };
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136 |
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137 | return Parser;
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138 | }, {
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139 | isClass: true
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140 | }); |
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