Technical Overview
Dart is a new class-based programming language for creating structured web applications. Developed with the goals of simplicity, efficiency, and scalability, the Dart language combines powerful new language features with familiar language constructs into a clear, readable syntax.
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Key features
Key features of the Dart language include:
- Classes
- Classes and interfaces provide a well understood mechanism for efficiently defining APIs. These constructs enable encapsulation and reuse of methods and data.
- Optional types
- Dart programmers can optionally add static types to their code. Depending on programmer preference and stage of application development, the code can migrate from a simple, untyped experimental prototype to a complex, modular application with typing. Because types state programmer intent, less documentation is required to explain what is happening in the code, and type-checking tools can be used for debugging.
- Libraries
- Developers can create and use libraries that are guaranteed not to change during runtime. Independently developed pieces of code can therefore rely on shared libraries.
- Tooling
- Dart will include a rich set of execution environments, libraries, and development tools built to support the language. These tools will enable productive and dynamic development, including edit-and-continue debugging and beyond—up to a style where you program an application outline, run it, and fill in the blanks as you run.
Design goals
The Dart programming language is presented here in its early stages. The following design goals will guide the continued evolution and refinement of this open source project:
- Create a structured yet flexible programming language for the web.
- Make Dart feel familiar and natural to programmers and thus easy to learn.
- Ensure that all Dart language constructs allow high performance and fast application startup.
- Make Dart appropriate for the full range of devices on the web—including phones, tablets, laptops, and servers.
- Provide tools that make Dart run fast across all major modern browsers.
These design goals address the following problems currently facing web developers:
- Small scripts often evolve into large web applications with no apparent structure—they’re hard to debug and difficult to maintain. In addition, these monolithic apps can’t be split up so that different teams can work on them independently. It’s difficult to be productive when a web application gets large.
- Scripting languages are popular because their lightweight nature makes it easy to write code quickly. Generally, the contracts with other parts of an application are conveyed in comments rather than in the language structure itself. As a result, it’s difficult for someone other than the author to read and maintain a particular piece of code.
- With existing languages, the developer is forced to make a choice between static and dynamic languages. Traditional static languages require heavyweight toolchains and a coding style that can feel inflexible and overly constrained.
- Developers have not been able to create homogeneous systems that encompass both client and server, except for a few cases such as Node.js and Google Web Toolkit (GWT).
- Different languages and formats entail context switches that are cumbersome and add complexity to the coding process.
