tco_brackets.js
No OneTemporary
Actions

Size

2 KB

Referenced Files

None

Subscribers

None

tco_brackets.js
View Options

	import { test, summary } from './helpers.js';

	console.log('TCO Bracket Edge Cases\n');

	function indexCallResult(n) {
	if (n <= 0) return [42];
	return indexCallResult(n - 1);
	}
	test('f() then index (small)', indexCallResult(5)[0], 42);

	function indexByCall(n) {
	if (n <= 0) return [99];
	return indexByCall(n - 1);
	}
	function zeroFn() {
	return 0;
	}
	test('f()[g()] (small)', indexByCall(3)[zeroFn()], 99);

	function returnBracketAccess(arr) {
	return arr[0];
	}
	test('bare bracket access', returnBracketAccess([7]), 7);

	function indexArrByCall(arr) {
	return arr[zeroFn()];
	}
	test('arr[f()] access', indexArrByCall([55]), 55);

	const methods = {
	greet() {
	return 'hello';
	},
	farewell() {
	return 'bye';
	}
	};
	function computedCall(key) {
	return methods[key]();
	}
	test('obj[key]() simple', computedCall('greet'), 'hello');
	test('obj[key]() simple 2', computedCall('farewell'), 'bye');

	const ops = {
	dec(n) {
	return recurseViaComputed(n - 1);
	}
	};
	function recurseViaComputed(n) {
	if (n <= 0) return 'done';
	return ops['dec'](n);
	}
	test('obj[key]() deep recursion', recurseViaComputed(100000), 'done');

	function callWithBracketArg(arr) {
	return identity(arr[0]);
	}
	function identity(x) {
	return x;
	}
	test('f(a[0]) bracket in arg', callWithBracketArg([33]), 33);

	function callWithBracketBinopArg(arr) {
	return identity(arr[0] + arr[1]);
	}
	test('f(a[0]+a[1]) binop inside args', callWithBracketBinopArg([10, 20]), 30);

	function recurseWithBracketArg(arr, i) {
	if (i >= arr.length) return 0;
	return recurseWithBracketArg(arr, i + 1);
	}
	test('deep with bracket arg', recurseWithBracketArg(new Array(100000), 0), 0);

	const handlers = {};
	for (let i = 0; i < 10; i++) {
	handlers['h' + i] = function (n) {
	if (n <= 0) return 'handled';
	return handlers['h' + i](n - 1);
	};
	}
	test('obj[key+expr]() result', handlers['h0'](50), 'handled');

	const dispatch = {
	action_run(n) {
	if (n <= 0) return 'ran';
	return dispatch['action' + '_' + 'run'](n - 1);
	}
	};
	test('obj[a+b]() deep (may fail without bracket fix)', dispatch['action_run'](100000), 'ran');

	const table = [];
	for (let i = 0; i < 20; i++) {
	table[i] = function () {
	return i;
	};
	}
	function callFromTable(a) {
	return table[a * 2 + 1]();
	}
	test('table[a*2+1]() computed', callFromTable(3), 7);

	function ternaryBracket(arr, flag) {
	return flag ? identity(arr[0]) : identity(arr[1]);
	}
	test('ternary with bracket args true', ternaryBracket([10, 20], true), 10);
	test('ternary with bracket args false', ternaryBracket([10, 20], false), 20);

	function ternaryComputedVsPlain(flag, n) {
	if (n <= 0) return 'end';
	return flag ? ops['dec'](n) : ternaryComputedVsPlain(flag, n - 1);
	}
	test('ternary computed vs plain', ternaryComputedVsPlain(false, 100000), 'end');

	summary();

File Metadata

Mime Type: application/javascript
Expires: Sat, Mar 28, 10:54 AM (2 d)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 513498
Default Alt Text: tco_brackets.js (2 KB)

Event Timeline