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load(libdir + 'iteration.js');
let makeCall = farg => Function("f", "arg", "return f(" + farg + ");");
let makeFunCall = farg => Function("f", "arg", "return f.call(null, " + farg + ");");
let makeNew = farg => Function("f", "arg", "return new f(" + farg + ").length;");
function checkLength(f, makeFn) {
assertEq(makeFn("...[1, 2, 3]")(f), 3);
assertEq(makeFn("1, ...[2], 3")(f), 3);
assertEq(makeFn("1, ...[2], ...[3]")(f), 3);
assertEq(makeFn("1, ...[2, 3]")(f), 3);
assertEq(makeFn("1, ...[], 2, 3")(f), 3);
assertEq(makeFn("...[1]")(f), 1);
assertEq(makeFn("...[1, 2]")(f), 2);
assertEq(makeFn("...[1, 2, 3, 4]")(f), 4);
assertEq(makeFn("1, ...[2, 3, 4], 5")(f), 5);
assertEq(makeFn("...[undefined]")(f), 1);
// other iterable objects
assertEq(makeFn("...arg")(f, new Int32Array([1, 2, 3])), 3);
assertEq(makeFn("...arg")(f, "abc"), 3);
assertEq(makeFn("...arg")(f, [1, 2, 3][Symbol.iterator]()), 3);
assertEq(makeFn("...arg")(f, new Set([1, 2, 3])), 3);
assertEq(makeFn("...arg")(f, new Map([["a", "A"], ["b", "B"], ["c", "C"]])), 3);
let itr = {};
itr[Symbol.iterator] = function() {
return {
i: 1,
next: function() {
if (this.i < 4)
return { value: this.i++, done: false };
else
return { value: undefined, done: true };
}
};
}
assertEq(makeFn("...arg")(f, itr), 3);
function* gen() {
for (let i = 1; i < 4; i ++)
yield i;
}
assertEq(makeFn("...arg")(f, gen()), 3);
}
checkLength(function(x) { return arguments.length; }, makeCall);
checkLength(function(x) { return arguments.length; }, makeFunCall);
function lengthClass(x) {
this.length = arguments.length;
}
checkLength(lengthClass, makeNew);