designscript.js

An attempt at writing a DesignScript parser and interpreter that runs in the browser. You can use it to parse, generate, and run DesignScript code. Because there is no spec for the DesignScript language, it probably has semantic issues. :)

Most of the project is written in TypeScript.

This project currently includes:

• AST
• Parser
• Interpreter (with debugging support)

Language features:

• Language blocks (Imperative and Associative)
• Replication
• Replication guides
• Type declaration for variables, function arguments
• Range expressions

See src/AST.ts for a complete list.

Not yet implemented

• For, while loops in imperative blocks
• Classes

Installing from npm

# npm install designscript.js

DesignScript.js is generated with browserify, so you can use it with a variety of module systems (see below).

Usage

Code generation

var AST = require('./build/designscript').AST;

var sl = 
	new AST.StatementListNode(
		new AST.AssignmentNode(
			new AST.IdentifierNode("a", new AST.Type("number")),
			new AST.NumberNode("3.14159")));
		
console.log( sl.toString() ); // prints "a : number = 3.14159;"

Parser

var designscript = require('./build/designscript');

// parse some DesignScript
var ast = designscript.Parser.parse('w = [Imperative]{ return = 4; }'); 

Interpreter

Continuing from the Parser example:

var i = new designscript.Interpreter();
i.run( ast ); 

console.log( i.env.lookup("w") ); // prints "4"

Debugging

Pass a function to an Interpreter that will be invoked upon consuming every part of the AST. When invoked, the Interpreter passes along a callback that must be invoked in order to continue execution.

var interpreter = new designscript.Interpreter(
	function(node, env, stack, callback){
		// do stuff with node, env, stack
		callback();
	});
interpreter.run( ast ); 
 

See example/debugger.html for a more complete example.

Install

Install node.js

# npm install -g jison
# npm install -g browserify
# npm install -g typescript

Build

# make build

Build for the web

# make release

Produces designscript.js in the build directory

Test

# make test