Scheme vs Haxe

Scheme syntax is extremely regular and easy to pick up. A formal specification of the syntax fits onto just a few pages; it can be introduced informally in a paragraph or two. Students are not distracted by remembering how to write if statements or loops or even operator precedence because every syntactic follows the same pattern.

Ultimately, everything looks something like this:

(func a b c)

This includes not only user-defined functions but even control flow:

(if cond then-clause else-clause)

or even primitive operations like define and set:

(define foo 10)
(set! foo 11)

This means that nothing really has special syntactic treatment in the language. There are essentially no weird edge-cases to memorize, and different concepts are given a more equal weight in the language. (Unlike Algol-like languages which tend to given undue weight to loops and assignment statements, for example.)

Scheme has far less built into the language itself, helping students see that things like OOP are not magical: they are just patterns for organizing code. Everything in Scheme is built up from a very small set of primitives which compose in a natural and intuitive fashion.

Having a language that does not accord many things special status helps keep students open minded. This will help students later go between different languages and paradigms from procedural to object-oriented to functional.

Scheme teaches the important, fundamental ideas immediately without the distraction of unnecessary syntax or language features.

GNU/Linux, OS X, and Windows versions available.

There is a set of very strong textbooks introducing CS and programming using Scheme. These books are available for free online.

The most famous example--and one of the most famous CS books full stop--is Structure and Interpretation of Computer Programs usually known as SICP. This book introduces fundamental ideas in computer science and covers an incredible amount of material quickly and clearly without requiring any prior knowledge.

However, some people find SICP a bit challenging as a first text. Happily, there are other more introductory texts as well. Simply Scheme is a book designed to be read before SICP, easing beginners into the language as well as CS and programming in general. How to Design Programs is another text used in introductory college courses.

The quotation functionality of Lisp allow for extremely powerful, yet syntactically straightforward metaprogramming via macros. This is more powerful than the C preprocessor while being less involved than something like Template Haskell or F# quotations.

Using macros to properly decompose a problem domain teaches new developers good habits, improving composibility and reliability when tackling large programs. Scheme metaprogramming also serves as a gentle introduction to domain specific languages.

Unlike most languages, Scheme actually accords both functional programming and imperative programming roughly equal status. Many other languages like Python and Java are staunchly imperative while SML and Haskell are primarily functional; Scheme is a nice middle ground.

Additionally, since Scheme syntax is extremely flexible, it can easily be re-purposed for teaching non-deterministic and logic programming. There is no need to learn a new language like Prolog when the same ideas can easily be expressed with Scheme syntax.

This gives students a good perspective on different ways to think about and organize programs, which makes it much easier to move forward to other languages and technologies.

Haxe allows you to develop for Web, iOS, Android, Blackberry, Windows, OSX, Linux and others, all at once, without the need to switch languages and maintain separate code bases.

This is possible because Haxe can compile to JavaScript, ActionScript, Flash AVM bytecode, C++, Neko, PHP, C# (.NET) and Java.

Support for even more platforms and languages is under development.

The language was designed to be very expressive with the smallest possible amount of syntactic sugar. There are actually fewer keywords than other languages with similar power.

Haxe can easily compile over 100,000 lines of code to JS in seconds on a mid-spec computer.

The language is very easy to learn for those with background in JavaScript or ActionScript 3.

Haxelib (common library repo) and other sources contain large codebases for anything from cryptography to communications. A lot of these are fully cross platform and work with the JavaScript target.

The JavaScript target can be used for everything from node.js server applications (with code completion) to games using either the Flash-like OpenFL library or direct canvas or WebGL programming.

Haxe has been around for more than 10 years (since 2005) and whilst not the most popular project, has had continuous growth.

Highly unlikely to disappear or for support to stop.

Friendly community

One big advantage over pure javascript, (or some other languages listed here) is that Haxe will pick up a whole range of errors when you compile, saving you the pain of having to try and debug them later. This includes everything from syntax errors ("Unexpected ;") to type errors ("Class user has no field username. Suggestion: username").

Code completion is built into the compiler and available to the IDE allowing for much smarter code completion that can actually parse and understand the syntax tree.

The output that is generated can be trimmed using "dead code elimination" to only include those functions and libraries that are strictly necessary. All code is very readable with only minimal extras for specific functionality.

Small output is good for frontend development as file size is a major concern.

After a type is inferred from its context, it cannot be changed to a new type, and type safety is done at compile time so it stays safe without the extra maintenance required for static typing.

Syntactic macros allow you to extend compiler features at the syntax tree step. Macros come into play after code is parsed into the abstract syntax tree, and macros allow you to transform it before the rest of the compilation completes.

This provides for immense power, while at the same time scoping the extensibility at a level that is powerful, but well constrained.

You can use the same classes on the server as you do on the client where applicable. This saves a lot of time.

Haxe has the ability to use "externs". These are haxe files which describe the usage of existing JS libraries. Get code completion and compile-time-checking for everything from jQuery to Node.js.

Even without externs, native JS code can still be used through untyped code.

Haxe has the power and expression to not need the npm dependancy hell that is common in js and typescript, bit it's still simple.

Using a remoting proxy you can get type safe server to client communications, allowing for remote method execution on the server as if they were part of the client side code.

Package tree is just directory tree, it's wonderful!

Haxe supports conditional compilation, so depending on compiler flags Haxe will include or exlcude sections of your code. Making it easy to have debug and release builds.

You can define constants in an abstract enum and when used in a switch/case statement Haxe checks for exhaustiveness, making sure every constant is covered - with no runtime implication.

Haxe compiler will check types when using externs for existing libraries.

You should use externs when calling non Haxe code, but if you just need to call one or two external JS functions, you can skip type checking by calling untyped code.