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node_modules/core-js/internals/string-multibyte.js

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+'use strict';
+var uncurryThis = require('../internals/function-uncurry-this');
+var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
+var toString = require('../internals/to-string');
+var requireObjectCoercible = require('../internals/require-object-coercible');
+
+var charAt = uncurryThis(''.charAt);
+var charCodeAt = uncurryThis(''.charCodeAt);
+var stringSlice = uncurryThis(''.slice);
+
+var createMethod = function (CONVERT_TO_STRING) {
+  return function ($this, pos) {
+    var S = toString(requireObjectCoercible($this));
+    var position = toIntegerOrInfinity(pos);
+    var size = S.length;
+    var first, second;
+    if (position < 0 || position >= size) return CONVERT_TO_STRING ? '' : undefined;
+    first = charCodeAt(S, position);
+    return first < 0xD800 || first > 0xDBFF || position + 1 === size
+      || (second = charCodeAt(S, position + 1)) < 0xDC00 || second > 0xDFFF
+        ? CONVERT_TO_STRING
+          ? charAt(S, position)
+          : first
+        : CONVERT_TO_STRING
+          ? stringSlice(S, position, position + 2)
+          : (first - 0xD800 << 10) + (second - 0xDC00) + 0x10000;
+  };
+};
+
+module.exports = {
+  // `String.prototype.codePointAt` method
+  // https://tc39.es/ecma262/#sec-string.prototype.codepointat
+  codeAt: createMethod(false),
+  // `String.prototype.at` method
+  // https://github.com/mathiasbynens/String.prototype.at
+  charAt: createMethod(true)
+};