skb-js

Dead-simple functional JavaScript transpiler.

SaurScript looks like this:

String myName = "Computer"
fun sayHi(String name) > String {
  return concat("Hello ", name)
}
String greeting = sayHi(myName)
logger.log(greeting)

It compiles to JavaScript:

const myName = "Computer";
const greeting = (function(name = myName) {
  return "Hello " + name;
})();
console.log(greeting)

Features

• Functional
• Pure
• Statically typed
• Lazy
• Easy to learn

Concept

A lot of functional programming languages use unfamiliar syntax:

myName = "Computer"

sayHi :: String -> String
sayHi name = "Hello " ++ name

greeting = sayHi myName
main = print greeting

This can make it hard to learn. SaurScript uses more familiar syntax, making it easier to learn.

Learn SaurScript

To learn how to use SaurScript we're going to create a thesaurus.

Imports

Usually you'll want to import either the common or browser library to start. These give you access to logger, document, storage, map, strConcat, filter, and other useful tools. You can also import other .saur files.

// The common lib:
@import 'common'
// The browser lib (this includes common, but is only for frontend dev. Don't use both):
@import 'browser'
// Another `.saur` file:
@import 'myOtherFile'

Variables

Variables in SaurScript are immutable and statically typed.

Int myVar = 5

This will compile to:

const myVar = 5;

You must specify a type to create the variable. Once you create the variable, you cannot change it.

Don't think of variables as boxes where you can take things in and out. Think of the variable name as a word in our thesaurus, and the value is the synonyms.

Let's create an entry for our thesaurus:

Dictionary<String:Array<String>> entries = ["Dinosaur": "Dino", "Raptor", "Big Lizard"]

Here we declare a new variable named entries. It's type is a Dictionary. The key of the dictionary is a String (a word), and the value is an Array of Strings (synonyms).

Functions

Functions are lazy. If we don't use the function, it won't show up in our JavaScript code.

fun myFunction(Int arg1, Float arg2) -> Bool {
  logger.log(arg1 + arg2)
  return true
}

Since we don't use this function, our JavaScript file is empty.

Let's add a function to our thesaurus to get the synonyms for any given word.

fun synonyms(String word) -> Array<String> {
  return entries[word]
}

Classes

Classes are an experimental feature of SaurScript. They mix the Functional and Object Oriented paradigms.

@class MyClass
  @property Int id = 0
  fun whoami() -> String {
    return "A Computer"
  }
@endclass
@new MyClass myInstance(5)
logger.log(myInstance.whoami())

This will compile to:

function MyClass(id = 0) {
  this.id = id;
};
MyClass.prototype = {
  whoami: function() {
    return "A Computer"
  }
}
const myInstance = new MyClass(5)
console.log(myInstance.whoami())

Now we can create a class for each entry in our thesaurus:

@class Entry
  @property String word = ""
  @property Array<String> synonyms = []
@endclass

And a class for the thesaurus itself:

@class Thesaurus
  @property String name = ""
  @property String publisher = ""
  @property Array<Any> entries = []
@endclass

And we can create a thesaurus!

@new Entry dino("Dino", ["Dinosaur", "Raptor", "T-Rex"]
@new Entry lizard("Lizard", ["Iguana", "Gecko", "Monitor"]
@new Entry paradigm("Paradigm", ["Functional", "Imperative", "Object Oriented"]
@new Thesaurus thesaurus("SaurScript Thesaurus", "SaurScript Language", [dino, lizard, paradigm])

If, Else If, and Else

if myCondition == "yes" {
  logger.log("Agreed")
} elif myCondition != "maybe" {
  logger.log("So you're telling me there's a chance")
} else {
  logger.log("Not at all")
}

Repeat

SaurScript doesn't have for or while loops. Instead, you can use recursion, or repeat.

repeat 3 {
  logger.log("Hi")
}

Output:

Hi
Hi
Hi

We can use recursion to print all of the synonyms in our thesaurus:

@class Thesaurus
  ...
  fun allSynonyms(Int index = 0, Array<String> soFar) {
    if entries[index] != null {
      allSynonyms(index + 1, arrConcat(soFar, entries[index])
    } else {
      logger.log(soFar)
    }
  }
@endclass

Exports

Sometimes you want to export something for use in another .saur file. You can add @export in front of a variable, class, function, etc. to make it available outside the file.

@export String myName = "Carson"

@export @class myClass
  @property String greeting = "Hello World"
@endclass

@export @new myClass greeter(strConcat("Hello ", myName))

@export fun sayHi(Any greeterClass) > String {
  return greeterClass.greeting
}

It can now be imported from another .saur file:

@import 'myFile'
// We can now access everything @exported from the other file:
logger.log(sayHi(greeter))