const initialState = {
  operand1: null,
  operand2: null,
  selectedOperation: null,
  result: null,
  error: null,
};

const state = { ...initialState };

export function getOperand1() { return state.operand1; }
export function setOperand1(value) { state.operand1 = value; }

export function getOperand2() { return state.operand2; }
export function setOperand2(value) { state.operand2 = value; }

export function getSelectedOperation() { return state.selectedOperation; }
export function setSelectedOperation(value) { state.selectedOperation = value; }

export function getResult() { return state.result; }
export function setResult(value) { state.result = value; }

export function getError() { return state.error; }
export function setError(value) { state.error = value; }

export function reset() { Object.assign(state, initialState); }