ScratchScript

ScratchScript is a typescript-like programming language that compiles to Scratch projects (.sb3).

It uses ANTLR4 for tokenizing/parsing and has an IR language that converts assembly-like commands to Scratch blocks.

Wiki/Documentation (outdated)

Code sample

import 'scratch/looks';

function add(x: number, y: number) {
    // return values in functions:
    return x + y;
}

on start {
    sayTimed('hello world!', 1);
    sayTimed('ScratchScript has all kinds of features that native Scratch lacks, like:', 5);
    sayTimed(`string interpolation: ${2 + 2} <- should be 4`, 3);
    sayTimed(`nested function calls: ${add(3, add(5, 2))} <- should be 10`, 3);
    
    // for loops:
    for(let i = 0; i < 10; i++) {
        // ...
    }
    
    // ternary operator:
    let theory = 2 + 2 == 4 ? "correct": "incorrect";
    
    // exponents and bitwise operations:
    let num = (2 ** 3) >> 3;
    
    // ...and much more!
}   

State

ScratchScript is currently being rewritten to have unit tests, proper project structure & common sense.

Implemented features

• Frontend
  • Enums
    • Declaration
    • Usage
    • enum.value and enum.name
    • Export
  • Variables
    • Declaration
    • Assignment
    • Function arguments
    • const & exporting consts
  • Lists
    • Declaration of 1D lists
    • Access of 1D lists
    • Declaration of multidimensional lists
    • Access of multidimensional lists
    • Passing a list as a function argument
    • Initializing variables with lists (list expressions)
  • Expressions
    • Constant expressions
    • Identifier expressions
    • Interpolated string expressions
    • Binary expressions
      • Binary add expressions (+, -, *, **, %, /)
      • Binary compare expressions (>, >=, <, <=, ==, !=)
      • Binary shift expressions (>>, <<)
      • Binary bitwise expressions (&, |, ^)
    • Unary expressions (+, -, !)
    • Function call expressions (a())
    • Member function call expressions (a.b())
    • Member property access expressions (a.b)
      • Enum property access
      • toString for all base types
      • Custom type properties?
    • Ternary expressions (a ? b: c)
  • Attributes
    • @inline
    • @import (asset importing)
    • @unicode
  • Functions
    • Declaration
    • Call
    • Export (a.k.a. dependencies handling)
  • Control flow
    • While loop
    • For loop
    • Foreach loop
    • Repeat loop
    • Breaking out of loops
    • If/else if/else statements
    • Switch statements
  • Imports
    • Handling name collisions
    • Importing specific items instead of all
    • Namespaces & namespace aliases (import * as math from 'std/math')
  • Events
    • start
    • stop
    • Built-in Scratch events
    • Custom events (broadcasts)
  • Other
    • throw
    • debugger
  • std library
    • std/native (a.k.a the scratch namespace)
      • scratch/control
      • scratch/data
      • scratch/looks
      • scratch/motion
      • scratch/operators
      • scratch/sensing
      • scratch/sound
    • std/string
      • std/string/unicode
    • std/math