ROADMAP.md

Reference

Icon	Meaning
✅	Implemented
🔲	Planned
〰️	Deprioritized - open an issue if you want this.
❌	Will not be implemented - nonstandard or deprecated API
⬇️	Will not be implemented - nonidiomatic TS or could cause performance issues

Keywords

Progress	Feature	Notes
〰️	arguments	I can do this, but does anyone want it?
🔲	async	Oh boy
✅	break	Still need to do labelled breaks
🔲	case
〰️	catch	See exception handling section below
🔲	class	See class section below
✅	const
✅	continue	Still need to do labelled continues
〰️	debugger	Hah! One day... one day...
🔲	default
〰️	delete	not sure if I want to support this for arrays
🔲	do
✅	else
🔲	export
🔲	extends	See class section below
🔲	finally	See exception handling section below
✅	for
✅	function	See function section below
✅	if
🔲	import
〰️	in	will not support for...in, except maybe on objects.
🔲	instanceof
🔲	new
✅	return
🔲	super
🔲	switch
✅	this
〰️	throw
〰️	try
🔲	typeof
❌	var	Use let or const
〰️	void	seems unnecessary, but not hard to add
🔲	while
❌	with	Will definitely never add this.
🔲	yield	Oh boy.

Classes

Progress	Feature	Notes
🔲	Implementation	Got some basic stuff in place, but there's still a lot of details to be worked out.
🔲	Constructors
🔲	instanceof checks
🔲	Properties
🔲	Methods
🔲	super
🔲	Static Methods
🔲	Static Properties
🔲	Private modifier	There isn't much to do here since TS will enforce this.
🔲	Getters / Setters
🔲	Inheritance	Oh boy

Functions

Progress	Feature	Notes
✅	Function declarations
✅	Method declarations
✅	Arrow functions
〰️	Function expressions	Use arrow functions - it's difficult to ensure this is typed correctly.
✅	Arrow functions
🔲	Closures
🔲	Default arguments
🔲	Optional arguments
⬇️	Function.prototype.apply	Might be possible, need to investigate (https://github.com/Microsoft/TypeScript/pull/27028)[this PR]
⬇️	Function.prototype.bind	Might be possible, need to investigate (https://github.com/Microsoft/TypeScript/pull/27028)[this PR]
⬇️	Function.prototype.call	Might be possible, need to investigate (https://github.com/Microsoft/TypeScript/pull/27028)[this PR]

Modules

Progress	Feature	Notes
🔲	Rudimentary module loading and bundling
✅	Import function declarations
✅	Import class declarations	there are no real classes yet but i'm prepared
🔲	Absolute paths
🔲	Relative paths

Standard Library

Strings

Progress	Feature	Notes
✅	String literals
✅	String equality with ===
🔲	Concatenate strings with +
✅	String.fromCharCode()
〰️	String.fromCodePoint()
❌	String.prototype.anchor()	deprecated API
❌	String.prototype.big()	deprecated API
❌	String.prototype.blink()	deprecated API
❌	String.prototype.bold()	deprecated API
✅	String.prototype.charAt()
✅	String.prototype.charCodeAt()
〰️	String.prototype.codePointAt()
✅	String.prototype.concat()	need to handle varags
✅	String.prototype.endsWith()
❌	String.prototype.fixed()	deprecated API
❌	String.prototype.fontcolor()	deprecated API
❌	String.prototype.fontsize()	deprecated API
✅	String.prototype.includes()
✅	String.prototype.indexOf()
❌	String.prototype.italics()	deprecated API
✅	String.prototype.lastIndexOf()
❌	String.prototype.link()	deprecated API
〰️	String.prototype.localeCompare()
〰️	String.prototype.match()
〰️	String.prototype.normalize()
🔲	String.prototype.padEnd()
🔲	String.prototype.padStart()
❌	String.prototype.quote()	deprecated API
✅	String.prototype.repeat()
🔲	String.prototype.replace()
🔲	String.prototype.search()
🔲	String.prototype.slice()
❌	String.prototype.small()	deprecated API
🔲	String.prototype.split()
🔲	String.prototype.startsWith()
❌	String.prototype.strike()	deprecated API
❌	String.prototype.sub()	deprecated API
❌	String.prototype.substr()	deprecated API
🔲	String.prototype.substring()
❌	String.prototype.sup()	deprecated API
〰️	String.prototype.toLocaleLowerCase()
〰️	String.prototype.toLocaleUpperCase()
🔲	String.prototype.toLowerCase()
〰️	String.prototype.toSource()
🔲	String.prototype.toString()
🔲	String.prototype.toUpperCase()
🔲	String.prototype.trim()
🔲	String.prototype.trimEnd()
🔲	String.prototype.trimStart()
🔲	String.prototype.valueOf()
🔲	String.prototype@@iterator
〰️	String.raw()

Array

Properties

Progress	Feature	Notes
✅	Array.length
⬇️	Array.prototype
⬇️	Array.prototype[@@unscopables]	We will not support with

Methods

Progress	Feature	Notes
🔲	Array.from()
🔲	Array.isArray()
❌	Array.observe()	deprecated API
🔲	Array.of()
✅	Array.prototype.concat()	Needs var-arg support
🔲	Array.prototype.copyWithin()
🔲	Array.prototype.entries()
🔲	Array.prototype.every()
🔲	Array.prototype.fill()
🔲	Array.prototype.filter()
🔲	Array.prototype.find()
🔲	Array.prototype.findIndex()
🔲	Array.prototype.flat()
🔲	Array.prototype.flatMap()
🔲	Array.prototype.forEach()
🔲	Array.prototype.includes()
✅	Array.prototype.indexOf()
🔲	Array.prototype.join()
🔲	Array.prototype.keys()
🔲	Array.prototype.lastIndexOf()
✅	Array.prototype.map()	needs to pass in index and current value
🔲	Array.prototype.pop()
✅	Array.prototype.push()
🔲	Array.prototype.reduce()
🔲	Array.prototype.reduceRight()
✅	Array.prototype.reverse()
🔲	Array.prototype.shift()
🔲	Array.prototype.slice()
🔲	Array.prototype.some()
🔲	Array.prototype.sort()
🔲	Array.prototype.splice()
🔲	Array.prototype.toLocaleString()
🔲	Array.prototype.toSource()
🔲	Array.prototype.toString()
🔲	Array.prototype.unshift()
🔲	Array.prototype.values()
🔲	Array.prototype@@iterator
❌	Array.unobserve()	deprecated API
🔲	get Array[@@species]