This is a simple CLI program that is a simulation of a simple toy robot moving on a square tabletop, of dimensions 5 units x 5 units.

The name is derived from the fictional robot Norby, that small but very productive robot!

• There are no other obstructions on the table surface.
• The robot is free to roam around the surface of the table, but must be prevented from falling to destruction.
• Any movement that would result in the robot falling from the table must be prevented, however further valid movement commands must still be allowed.

PLACE X,Y,F
MOVE
LEFT
RIGHT
REPORT

• PLACE will put the toy robot on the table in position X,Y and facing NORTH, SOUTH, EAST or WEST.

• The origin (0,0) can be considered to be the SOUTH WEST most corner.

• The first valid command to the robot is a PLACE command, after that, any sequence of commands may be issued, in any order, including another PLACE command. The application should discard all commands in the sequence until a valid PLACE command has been executed.

• MOVE will move the toy robot one unit forward in the direction it is currently facing.

• LEFT and RIGHT will rotate the robot 90 degrees in the specified direction without changing the position of the robot.

• REPORT will announce the X,Y and orientation of the robot.

• A robot that is not on the table can choose to ignore the MOVE, LEFT, RIGHT and REPORT commands.

• Provide test data to exercise the application.

The toy robot must not fall off the table during movement. This also includes the initial placement of the toy robot. Any move that would cause the robot to fall must be ignored.

Add this line to your application's Gemfile:

$ gem install norby

And then execute:

$ norby

PLACE 0,0,NORTH
MOVE
REPORT
Output: 0,1,NORTH

PLACE 0,0,NORTH
LEFT
REPORT
Output: 0,0,WEST

PLACE 1,2,EAST
MOVE
MOVE
LEFT
MOVE
REPORT
Output: 3,3,NORTH

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec --- to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/wazery/norby.