michael@0: // (a) => expr
michael@0: 
michael@0: var f = (a) => 2 * a;  // parens are allowed
michael@0: assertEq(f(12), 24);
michael@0: var g = (a, b) => a + b;
michael@0: assertEq([1, 2, 3, 4, 5].reduce((a, b) => a + b), 15);