kovidgoyal / rapydscript-ng

RapydScript =========== This is a fork of the original RapydScript that adds many new (not always backwards compatible) features. For more on the forking, see the bottom of this file Try RapydScript-ng live via an in-browser REPL! **Contents** • What is RapydScript? • Installation • Compilation • Getting Started • Leveraging other APIs • Anonymous Functions • Decorators • Self-Executing Functions • Chaining Blocks • Function calling with optional arguments • Inferred Tuple Packing/Unpacking • Operators and keywords • Literal JavaScript • Containers (lists/sets/dicts) • Container comparisons • Loops • List/Set/Dict Comprehensions • Strings • The Existential Operator • Regular Expressions • Creating DOM trees easily • Classes • External Classes • Method Binding • Iterators • Generators • Modules • Exception Handling • Scope Control • Available Libraries • Linter • Making RapydScript even more pythonic • Advanced Usage Topics • Browser Compatibility • Tabs vs Spaces • External Libraries and Classes • Embedding the RapydScript compiler in your webpage • Internationalization • Gotchas • Reasons for the fork What is RapydScript? -------------------- RapydScript (pronounced 'RapidScript') is a pre-compiler for JavaScript, similar to CoffeeScript, but with cleaner, more readable syntax. The syntax is almost identical to Python, but RapydScript has a focus on performance and interoperability with external JavaScript libraries. This means that the JavaScript that RapydScript generates is performant and quite close to hand written JavaScript. RapydScript allows to write your front-end in Python without the overhead that other similar frameworks introduce (the performance is the same as with pure JavaScript). To those familiar with CoffeeScript, RapydScript is like CoffeeScript, but inspired by Python's readability rather than Ruby's cleverness. To those familiar with Pyjamas, RapydScript brings many of the same features and support for Python syntax without the same overhead. Don't worry if you've never used either of the above-mentioned compilers, if you've ever had to write your code in pure JavaScript you'll appreciate RapydScript. RapydScript combines the best features of Python as well as JavaScript, bringing you features most other Pythonic JavaScript replacements overlook. Here are a few features of RapydScript: • classes that work and feel similar to Python • an import system for modules/packages that works just like Python's • optional function arguments that work similar to Python • inheritance system that's both, more powerful than Python and cleaner than JavaScript • support for object literals with anonymous functions, like in JavaScript • ability to invoke any JavaScript/DOM object/function/method as if it's part of the same framework, without the need for special syntax • variable and object scoping that make sense (no need for repetitive 'var' or 'new' keywords) • ability to use both, Python's methods/functions and JavaScript's alternatives • similar to above, ability to use both, Python's and JavaScript's tutorials (as well as widgets) • it's self-hosting, that means the compiler is itself written in RapydScript and compiles into JavaScript Let's not waste any more time with the introductions, however. The best way to learn a new language/framework is to dive in. Installation ------------ Try RapydScript-ng live via an in-browser REPL! First make sure you have installed the latest version of node.js (You may need to restart your computer after this step). From NPM for use as a command line app: npm install rapydscript-ng -g From NPM for use in your own node project: npm install rapydscript-ng From Git: git clone https://github.com/kovidgoyal/rapydscript-ng.git cd rapydscript-ng sudo npm link . npm install # This will automatically install the dependencies for RapydScript If you're using OSX, you can probably use the same commands (let me know if that's not the case). If you're using Windows, you should be able to follow similar commands after installing node.js, npm and git on your system. Compilation ----------- Once you have installed RapydScript, compiling your application is as simple as running the following command: rapydscript [options] By default this will dump the output to STDOUT, but you can specify the output file using option. The generated file can then be referenced in your html page the same way as you would with a typical JavaScript file. If you're only using RapydScript for classes and functions, then you're all set. For more help, use . Getting Started --------------- RapydScript comes with its own Read-Eval-Print-Loop (REPL). Just run rapydscript without any arguments to get started trying out the code snippets below. Like JavaScript, RapydScript can be used to create anything from a quick function to a complex web-app. RapydScript can access anything regular JavaScript can, in the same manner. Let's say we want to write a function that greets us with a "Hello World" pop-up. The following code will do it: Once compiled, the above code will turn into the following JavaScript: Now you can reference this function from other JavaScript or the page itself (using "onclick", for example). For our next example, let's say you want a function that computes factorial of a number: Now all we need is to tie it into our page so that it's interactive. Let's add an input field to the page body and a cell for displaying the factorial of the number in the input once the input loses focus. **NOTE:** To complement RapydScript, I have also written RapydML ( ), which is a pre-compiler for HTML (just like RapydScript is a pre-compiler for JavaScript). Now let's implement computeFactorial() function in RapydScript: Again, notice that we have access to everything JavaScript has access to, including direct DOM manipulation. Once compiled, this function will look like this: Notice that RapydScript automatically declares variables in local scope when y…