When comparing Dart vs Pony, the Slant community recommends Pony for most people. In the question“What are the best (productivity-enhancing, well-designed, and concise, rather than just popular or time-tested) programming languages?” Pony is ranked 22nd while Dart is ranked 35th. The most important reason people chose Pony is:
The unique type system allows the compiler to automatically schedule actors on threads, giving you reliable concurrency for free.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Great async language support
Dart is a single threaded programming language. So if any piece of code blocks the execution of the program, the program practically freezes. To avoid this Dart makes use of asynchronous operations which let your program run without getting blocked. This is done through Future objects.
A Future is an object which represent a means for getting a value at a certain point in the future. A function may invoke a Future and when that happens, two outcomes can be achieved:
- The function is unable to return a value, so it queues up work to be done and returns an uncompleted Future object.
- Or later when a value is available to be returned, the Future object completes with that value.
Pro Great standard library
Dart includes a truly comprehensive core library, making it unnecessary to include disparate, external resources for basic functionalities Other than reducing the need to pull in various 3rd-party utilities this also ensures that all Dart code looks and feels the same.
Out of the box, the developer gets core libraries to help with: async, collections, strings, regexps, conversions, formats, file I/O, math, typed data, and more.
Pro No compile time in development
Dartium (Chromium derivative) is a browser with integrated Dart VM, which allows you to run and debug native Dart code during development for short edit-reload cycles. Only for testing on other browsers and deployment is transpiling to JS necessary.
Pro A lot of tools are available to help in developing with Dart
Dart has a lot of tools available which help with developing Dart applications. Some examples of those tools include:
- pub - package and dependency management and build tool
- analyzer - static syntax analysis with linter, quick fixes, autocompletion support for easy IDE integration
- test - powerful and flexible testing framework and test runner
- dev_compiler - generate reusable JS instead of tree-shaken minified JS output (work in progress)
- dartfmt_ - source code formatter
- server-side VM
- observatory - a powerful tool for profiling and debugging running Dart code (for Dartium and Dart server code)
Pro Transpiled JavaScript code works on all browsers
In Dart many browser differences (subtle differences and also missing features) are abstracted away or polyfilled. When Dart is transpiled to JS the output works on all supported browsers. There is usually no need to load polyfills or to consider browser differences during development. No need for libraries like jQuery to make the same code work the same on all browsers.
Pro Will be familiar to Java developers
The language will look familiar to Java developers, easing the learning curve.
And yet, while it's similar, it has some nice syntax facilities to avoid common boilerplate code found in Java. Code is terser, yet readable.
Pro Easy prototyping
Dart has an optional type system which makes Dart a great language for prototyping. It encourages developers to gradually evolve their programs without worrying about types first.
Pro Can compile to efficient machine code
Dart was designed to be as expressive as possible. Ahead-of-time compilers can compile Dart code to efficient machine code. This is especially important when deploying to mobile where you don't want (or can't) use a JIT.
Pro AngularDart 2.0 support
Pro Optional strong mode.
Strong mode applies a more restrictive type system to Dart to address its unsound, surprising behavior in certain cases.
Pro Support of semi-coroutines (generators)
Generators, also known as semicoroutines, are also a generalization of subroutines.
Generators are primarily used to simplify the control of iteration behavior of a loop, the yield
statement in a generator passes a value back to a parent routine.
A generator is very similar to a function that returns an array, in that a generator has a certain number of values. But instead of building and returning an array that contains all the wanted values, a generator returns them one at a time, this saves memory and allows the caller function to start processing the first few values immediately.
Pro The Dart to JavaScript compiler generates high quality source code
Dart to Javascript compiler (dart2js) generates very high quality source code with very high optimization. The output code is also very readable and easy to understand.
Pro Crossplatform
Dart does not just compile to JavaScript, it also compiles to native code on mobile platforms like iOS and Android as demonstrated by flutter.io
Pro Concurrency model based on actors
The unique type system allows the compiler to automatically schedule actors on threads, giving you reliable concurrency for free.
Pro Reliable
Because of its capabilities secure type system, provided you don't use the C FFI, references will never be stale, race conditions are effectively impossible, deadlocks don't happen because locks and mutexes are never needed, and processes never crash because all exceptions must be handled. (Barring compiler bugs or external memory corruption, of course.) Pony programs can still lock up due to infinite loops, like any Turing-complete language.
Pro High performance
Compiles to native code, and features an intelligent garbage collector that takes advantage of the actor architecture to get essentially free garbage collection.
Pro Trivially simple C FFI
Calling low-level C functions is as simple as use "lib:clibrary"
and @c_function_name[return_type](parameter:type)
. Linking C to Pony libraries is just as easy, as the Pony compiler will generate appropriate header files.
Cons
Con Doesn’t generate consumable JavaScript at present
Dart builds to JavaScript but the entire app needs to be built to JavaScript at once for now (that may change in the future).
Con Still many holes to fill while converting code to Javascript
While implementing callbacks, passing a type to any function that gets passed to Javascript causes the dart2js compiler to crash.
Con Dart SDK does not provide standard (out of the box) way to access SQL-based databases on server side
This missing (but very popular) feature requires to use 3rd-party packages developed by the personal enthusiasts or very small groups of enthusiasts, which is not very convenient because they are all very fragmented in terms of content, the essence and capabilities.
Con Small community, little momentum
Con May be difficult to use some JavaScript libraries
Dart is much more than a programming language, it's a platform with its own standard libraries and tools. It's a major departure from JavaScript itself (even though it can compile to JS) that it's not possible to directly interact with JavaScript libraries in Dart. Instead, you have to use a special interop library which exposes the wrapped versions of the JavaScript objects that you are accessing.
While this enables Dart to sandbox JavaScript so that its problems do not leak into a Dart application, it also means that it may be cumbersome to use libraries which don't have a wrapper library available.
Con All exceptions must be caught
The compiler enforces this, so code is littered with try
s.
Con Limited documentation
As Pony is such a new language, documentation is relatively light, and tutorials are few and far-between.
Con Few libraries
Con Garbage collector can't run until you yield
A long-running behavior can leak memory because the garbage collector has no chance to run.
Con Limited tooling
There's no IDE. Debuggers are fairly basic. Pony is too young to have much of an ecosystem.
Con Divide by zero is allowed
And instead of some sensible result like NaN or Inf, the answer is zero! Most languages would just raise an exception (and Pony used to do this), but since the compiler enforces the rule that "all exceptions must be caught" the proliferation of try
s was determined to be too burdensome on the programmer. This makes the whole design of the exception system questionable.
Con Unstable API
Pony is not ready for production. It has yet to release version 1.0, and there are frequent breaking changes.
Con Difficult learning curve
The type system uses a capabilities-oriented approach to reference semantics, which can be difficult to wrap your head around at first. The lack of more common object-oriented features and the preference for simplicity over familiarity can make it difficult for new users to model their program design.