chushihua

node_modules/es5-ext/array/#/binary-search.js

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+"use strict";
+
+var toPosInt = require("../../number/to-pos-integer")
+  , callable = require("../../object/valid-callable")
+  , value    = require("../../object/valid-value")
+  , floor    = Math.floor;
+
+module.exports = function (compareFn) {
+	var length, low, high, middle;
+
+	value(this);
+	callable(compareFn);
+
+	length = toPosInt(this.length);
+	low = 0;
+	high = length - 1;
+
+	while (low <= high) {
+		middle = floor((low + high) / 2);
+		if (compareFn(this[middle]) < 0) high = middle - 1;
+		else low = middle + 1;
+	}
+
+	if (high < 0) return 0;
+	if (high >= length) return length - 1;
+	return high;
+};