Generated by XState Viz: https://xstate.js.org/viz

machine.js

const lightMachine = Machine({
  key: 'light',
  initial: 'green',
  states: {
    green: {
      on: { NEXT: "yellow" }
    },
    yellow: {      on: { NEXT: "red" }},
    red: {
      initial: 'green',
      states: {
        green: {
          on: { NEXT: "yellow" }
        },
        yellow: {
          on: { NEXT: "red" }
        },
        red: {
          type: "parallel",
          states: {
            walkSign: {
              initial: "solid",
              states: {
                solid: {
                  on: { COUNTDOWN: "flashing" }
                },
                flashing: {
                  on: { STOP_COUNTDOWN: "solid"}
                }
              }
            },
            pedestrian: {
              initial: "walk",
              states: {
                walk: {
                  on: {
                    COUNTDOWN: "wait"
                  }
                },
                wait: {
                  on: {
                    STOP_COUNTDOWN: "stop"
                  }
                },
                stop: {}
              }
            }
          }
        }
      }
    }
  }
});

/*const pedestrianStates = {
  initial: 'walk',
  states: {
    walk: {
      on: {
        PED_COUNTDOWN: 'wait'
      }
    },
    wait: {
      on: {
        PED_COUNTDOWN: 'stop'
      }
    },
    stop: {},
    blinking: {}
  }
};

*/