text: export const range = (start, end) => {
    const result = [];
  
    for (let i = start; i < end; i++) {
      result.push(i);
    }
  
    return result;
  };
  
  export const flatten = lists => lists.reduce((x, y) => x.concat(y), []);
  
  export const from = list => {
    if (!list.length) {
      return [];
    }
  
    const result = [];
  
    for (let i = 0; i < list.length; i++) {
      result.push(list[i]);
    }
  
    return result;
  };
  