29 lines
799 B
JavaScript
29 lines
799 B
JavaScript
// Credit:
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// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/round
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// #Decimal_rounding
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"use strict";
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var isValue = require("type/object/is")
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, ensureInteger = require("type/integer/ensure");
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var split = String.prototype.split;
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module.exports = function (type) {
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return function (value/*, exp*/) {
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value = Number(value);
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var exp = arguments[1];
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if (isValue(exp)) exp = ensureInteger(exp);
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if (!value) return value;
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if (!exp) return Math[type](value);
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if (!isFinite(value)) return value;
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// Shift
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var tokens = split.call(value, "e");
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value = Math[type](tokens[0] + "e" + ((tokens[1] || 0) - exp));
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// Shift back
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tokens = value.toString().split("e");
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return Number(tokens[0] + "e" + (Number(tokens[1] || 0) + exp));
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};
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};
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