Traffic Light

This was completed as a warmup exercise to Dave's "Rafting Trip".

Most of the implementation was inspired by Hoverbear's post on state machines: https://hoverbear.org/blog/rust-state-machine-pattern/.

This Traffic Light simulation considers a light at a four-way intersection.

• A single East-West light

• A single North-South light

• A single push button to change the North-South light to red.

• The East-West light stays green for 30 seconds.

• The North-South light stays green for 60 seconds.

• Yellow lights always last 5 seconds.

• The push-button causes the North-South light to change immediately if it has been green for more than 30 seconds. If less than 30 seconds have elapsed, the light will change once it has been green for 30 seconds.

Usage

Assuming you have Rust and Cargo installed. If not, see https://rustup.rs/.

Running Tests

Tests can be found in src/lib.rs.

$ cargo test

Running the Application

To run the application debug release:

$ cargo run

To run the release application (no debug messages):

$ cargo run --release

Building Docs

To build and open the auto-generated documentation in your browser:

$ cargo doc --no-deps --open

TODOs

• Cycle the light between states based on time passed.
• Create intersection with two traffic lights in compatible states (East-West light and North-South light).
• Handle "button" press on on North-South light to change to red.

  The push-button causes the North-South light to change immediately if it has been green for more than 30 seconds. If less than 30 seconds have elapsed, the light will change once it has been green for 30 seconds.

• Write tests.
  • For verifying button press functionality and it's effect on state.