The Shrdlite course project

Shrdlite is a programming project in Artificial Intelligence, a course given at the University of Gothenburg and Chalmers University of Technology. For more information, see the course webpages:

• http://ChalmersGU-AI-course.github.io/

The goal of the project is to create an interpreter and a planner so that a person can control a robot in a blocks world to move around objects, by giving commands in natural language.

To make the project more interesting, there is a web-based graphical interface from which the user can interact with the blocks world.

The interface is written in TypeScript (which compiles into Javascript), and it can be run in two different modes:

• as a HTML web application, using SVG animations for displaying the world

• as an offline text application, where input is provided at the command line (requires that Node.JS is installed, but nothing of the terminal)

To be able to run the system you need to install Node.JS and TypeScript. Do that. Now.

What is already implemented

The natural language parser is already implemented using the Nearley parsing library.

Furthermore, there are two different implementations of the blocks world: the SVGWorld and the TextWorld, as well as some example worlds.

Additionally there are lots of other glue code already implemented, including an initial implementation of weighted graphs in Graph.ts.

What is missing

What is not implemented correctly is the natural language interpreter and the robot planner. What you are given are stubs that return a dummy interpretation and a dummy plan respectively. Your goal is to implement the interpreter and the planner so that the robot behaves as it should.

The following functions are only templates that you have to fill with intelligent code to get the project to work correctly:

• the function aStarSearch(...) in the file Graph.ts.
• the function interpretCommand(...) in the file Interpreter.ts.
• the function planInterpretation(...) in the file Planner.ts.
• possibly you will also want to modify the function parseUtteranceIntoPlan(...) in the file Shrdlite.ts.

Depending on which extension you want to implement, there might of course be several other places in the code that need modification.

About TypeScript

TypeScript is a typed superset of Javascript that compiles to plain Javascript. It is open-source and not specific to any browser or operating system.

For information about the language, please visit the official site:

• http://www.typescriptlang.org/

More detailed information

There is a Makefile if you want to use the GNU Make system. Here's what it can do:

• make clean: Removes all auto-generated Javascript files
• make all: Calls TypeScript for all targets
• make shrdlite-html.js | shrdlite-offline.js: Calls TypeScript for the given target, i.e., it compiles the file shrdlite-X.ts into shrdlite-X.js

Data structures

You probably want to use some kind of collection datatype (such as a heap and/or priority queue), and we suggest the following library:

• typescript-collections

In fact, you have to use this library anyway (in Graph.ts) and it's already included in the lib directory.

Using JavaScript modules in TypeScript

If you want to use standard JavaScript libraries in TypeScript, you have to add a TypeScript declaration file for that library. The DefinitelyTyped library contains declaration files for several libraries, such as the following two:

• node.d.ts
• jquery.d.ts

In fact, they are already included in the lib directory.

JavaScript chart parser

The parser is generated by Nearley. The grammar is in the file grammar.ne, and it is compiled into the Javascript file grammar.js. You don't have to install Nearley if you don't plan to make any changes in the grammar.

List of files

BSD Makefile for automatically creating .js files from .ts files:

• Makefile

Main browser files:

• shrdlite.html, shrdlite.css

Wrapper file for the browser-based interface:

• shrdlite-html.ts

Wrapper file for the Node.JS-based interface:

• shrdlite-offline.ts

Main TypeScript module:

• Shrdlite.ts

TypeScript interfaces and classes for the different implementations of the blocks world:

• World.ts, SVGWorld.ts, TextWorld.ts, ExampleWorlds.ts

TypeScript modules for parsing, interpretation and planning:

• Parser.ts, Interpreter.ts, Planner.ts

TypeScript module for weighted graphs:

• Graph.ts

Grammar files used by the Nearley chartparser:

• grammar.js, grammar.ne

External TypeScript libraries:

• lib/collections.ts

TypeScript declaration files for non-TypeScript libraries:

• lib/jquery.d.ts, lib/node.d.ts

External Javascript libraries:

• lib/jquery-1.11.0.min.js, lib/nearley.js