14 lines
509 B
JavaScript
Executable file
14 lines
509 B
JavaScript
Executable file
var anObject = require('../internals/an-object');
|
|
var aFunction = require('../internals/a-function');
|
|
var wellKnownSymbol = require('../internals/well-known-symbol');
|
|
|
|
var SPECIES = wellKnownSymbol('species');
|
|
|
|
// `SpeciesConstructor` abstract operation
|
|
// https://tc39.es/ecma262/#sec-speciesconstructor
|
|
module.exports = function (O, defaultConstructor) {
|
|
var C = anObject(O).constructor;
|
|
var S;
|
|
return C === undefined || (S = anObject(C)[SPECIES]) == undefined ? defaultConstructor : aFunction(S);
|
|
};
|