12. Glossary

Term	Definition
Plateau	The rectangular grid on Mars within which rovers operate. Defined by its upper-right corner (width, height); the lower-left corner is always (0, 0).
Rover	An autonomous vehicle deployed on the plateau. Holds a position (x, y) and a heading. Processes commands one at a time.
Position	A coordinate pair (x, y) on the plateau grid. x increases eastward; y increases northward.
Heading	The cardinal direction a rover is facing: N (North), E (East), S (South), or W (West).
Command	A single instruction sent to a rover. Valid values: L (turn left 90°), R (turn right 90°), M (move one step forward in the current heading direction).
Command String	A sequence of commands for a single rover, e.g. LMLMLMLMM.
Turn Left (L)	Rotate the rover 90° counter-clockwise without moving. N → W → S → E → N.
Turn Right (R)	Rotate the rover 90° clockwise without moving. N → E → S → W → N.
Move Forward (M)	Advance the rover one grid step in its current heading direction. Ignored if the move would leave the plateau.
Safe-Stop	The behaviour where a rover ignores a move command that would take it outside the plateau (or into an obstacle), remaining at its current position.
Obstacle	(Optional extension) A cell on the plateau that a rover cannot enter. Triggers a safe-stop before the blocked cell.
Mission	The complete execution of all command strings for all rovers on a given plateau.
Operator	The human (or system) that provides the plateau definition, rover starting positions, and command strings.
InputParser	The adapter component responsible for converting raw stdin text into domain objects (Plateau, Rover, Command list).
OutputFormatter	The adapter component responsible for converting final Rover state into the x y HEADING output string.
MissionController	The application-layer component that orchestrates a mission — iterating over rovers and applying their command sequences.
Hexagonal Architecture	An architectural style (also called Ports & Adapters) that isolates the domain from I/O by placing all external concerns in adapter classes.
ADR	Architecture Decision Record — a short document capturing a significant design decision, its context, and its consequences.
arc42	A lightweight, pragmatic template for software architecture documentation with 12 standardised chapters.
C4 Model	A hierarchical diagramming approach (Context → Container → Component → Code) for visualising software architecture.
PlantUML	A text-based diagramming tool used to author C4 diagrams in this project.