think49 · November 13, 2016 15:10 · think49 · Nov 13, 2016
diff --git a/eval-calculation-map-sample.html b/eval-calculation-map-sample.html
 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="UTF-8" />
 <title>eval-calculation-map-sample.js</title>
 <script>
 /**
 * eval-calculation-map-sample.js
 * evaluate calculation formula.
 *
 * @version 0.1.1
 * @author think49
 * @url https://gist.github.com/think49/47fb5dcd29c552550a73192df6f1d947
 * @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
 */

 var evalCalculation = (function (String, pow, max) {
  'use strict';

  function getDecimalPartLength (numberString) {
    var result = /\.\d+$/.exec(numberString);

    return result ? result[0].length - 1 : 0;
  }

  function calcDyadicOperator (matched, number1, operator, number2) {
    var decimalPart = /\.\d+$/, powerNumber1, powerNumber2, result;

    switch (operator) {
      case '+':
        powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
        result = (powerNumber1 * number1 + powerNumber1 * number2) / powerNumber1;
      break;
    case '-':
        powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
        result = (powerNumber1 * number1 - powerNumber1 * number2) / powerNumber1;
      break;
    case '*':
        powerNumber1 = pow(10, getDecimalPartLength(number1));
        powerNumber2 = pow(10, getDecimalPartLength(number2));
        result = (number1 * powerNumber1) * (number2 * powerNumber2) / (powerNumber1 * powerNumber2);
      break;
    case '/':
        powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
        result = (number1 * powerNumber1) / (number2 * powerNumber1);
      break;
    default:
      console.warn('expression: ' + number1 + operator + number2);
      throw new Error(operator + ' is not a operator');
    }

    // console.log(String(number1) + operator + number2 + '=' + result);
    return result;
  }

  return function evalCalculation (expression) {
    var multiplyOrDivide = /(-?(?:\d+(?:\.\d+)?|\.\d+))([*/])(-?(?:\d+(?:\.\d+)?|\.\d+))/g,
        addOrSubtract = /(-?(?:\d+(?:\.\d+)?|\.\d+))([+-])(-?(?:\d+(?:\.\d+)?|\.\d+))/g,
        errors = [],
        illegalString;

    expression = String(expression).replace(/\s+/g, '');

    if (illegalString = /^[+-]?(?:\.[^\d]|[^\d.+-])/.exec(expression)) {
      errors.push(new SyntaxError('An expression starts with an unexpected token: ' + illegalString[0]));
    }

    if (illegalString = /[^\d]$/.exec(expression)) {
      errors.push(new SyntaxError('An expression ends with an unexpected token: ' + illegalString[0]));
    }

    if (illegalString = /\d*(?:\.\d*){2,}/.exec(expression)) {
      errors.push(new SyntaxError('Illegal number: ' + illegalString[0]));
    }

    while (multiplyOrDivide.test(expression)) {
      expression = expression.replace(multiplyOrDivide, calcDyadicOperator);
    }

    while (addOrSubtract.test(expression)) {
      expression = expression.replace(addOrSubtract, calcDyadicOperator);
    }

    return new Map([['value', +expression], ['errors', errors]]);
  };
 }(String, Math.pow, Math.max));
 </script>
 </head>
 <body>
 <ul>
  <li><a href="https://teratail.com/questions/54897#r88021">JavaScript - エラーメッセージをまとめて出力する為の最適解は？(54897)｜teratail</a></li>
 </ul>
 <script>
 'use strict';
 var map = evalCalculation('/1.1.1*');
 console.log(map.get('value'));  // NaN
 console.log(map.get('errors'));  // [new SyntaxError('An expression starts with an unexpected token: /'), new SyntaxError('An expression ends with an unexpected token: *'), new SyntaxError('Illegal number: 1.1.1')]
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8" />
	<title>eval-calculation-map-sample.js</title>
	<script>
	/**
	* eval-calculation-map-sample.js
	* evaluate calculation formula.
	*
	* @version 0.1.1
	* @author think49
	* @url https://gist.github.com/think49/47fb5dcd29c552550a73192df6f1d947
	* @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
	*/

	var evalCalculation = (function (String, pow, max) {
	'use strict';

	function getDecimalPartLength (numberString) {
	var result = /\.\d+$/.exec(numberString);

	return result ? result[0].length - 1 : 0;
	}

	function calcDyadicOperator (matched, number1, operator, number2) {
	var decimalPart = /\.\d+$/, powerNumber1, powerNumber2, result;

	switch (operator) {
	case '+':
	powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
	result = (powerNumber1 * number1 + powerNumber1 * number2) / powerNumber1;
	break;
	case '-':
	powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
	result = (powerNumber1 * number1 - powerNumber1 * number2) / powerNumber1;
	break;
	case '*':
	powerNumber1 = pow(10, getDecimalPartLength(number1));
	powerNumber2 = pow(10, getDecimalPartLength(number2));
	result = (number1 * powerNumber1) * (number2 * powerNumber2) / (powerNumber1 * powerNumber2);
	break;
	case '/':
	powerNumber1 = pow(10, max(getDecimalPartLength(number1), getDecimalPartLength(number2)));
	result = (number1 * powerNumber1) / (number2 * powerNumber1);
	break;
	default:
	console.warn('expression: ' + number1 + operator + number2);
	throw new Error(operator + ' is not a operator');
	}

	// console.log(String(number1) + operator + number2 + '=' + result);
	return result;
	}

	return function evalCalculation (expression) {
	var multiplyOrDivide = /(-?(?:\d+(?:\.\d+)?\|\.\d+))([*/])(-?(?:\d+(?:\.\d+)?\|\.\d+))/g,
	addOrSubtract = /(-?(?:\d+(?:\.\d+)?\|\.\d+))([+-])(-?(?:\d+(?:\.\d+)?\|\.\d+))/g,
	errors = [],
	illegalString;

	expression = String(expression).replace(/\s+/g, '');

	if (illegalString = /^[+-]?(?:\.[^\d]\|[^\d.+-])/.exec(expression)) {
	errors.push(new SyntaxError('An expression starts with an unexpected token: ' + illegalString[0]));
	}

	if (illegalString = /[^\d]$/.exec(expression)) {
	errors.push(new SyntaxError('An expression ends with an unexpected token: ' + illegalString[0]));
	}

	if (illegalString = /\d(?:\.\d){2,}/.exec(expression)) {
	errors.push(new SyntaxError('Illegal number: ' + illegalString[0]));
	}

	while (multiplyOrDivide.test(expression)) {
	expression = expression.replace(multiplyOrDivide, calcDyadicOperator);
	}

	while (addOrSubtract.test(expression)) {
	expression = expression.replace(addOrSubtract, calcDyadicOperator);
	}

	return new Map([['value', +expression], ['errors', errors]]);
	};
	}(String, Math.pow, Math.max));
	</script>
	</head>
	<body>
	<ul>
	<li><a href="https://teratail.com/questions/54897#r88021">JavaScript - エラーメッセージをまとめて出力する為の最適解は？(54897)｜teratail</a></li>
	</ul>
	<script>
	'use strict';
	var map = evalCalculation('/1.1.1*');
	console.log(map.get('value')); // NaN
	console.log(map.get('errors')); // [new SyntaxError('An expression starts with an unexpected token: /'), new SyntaxError('An expression ends with an unexpected token: *'), new SyntaxError('Illegal number: 1.1.1')]
	</script>
	</body>
	</html>