import { Grid, Row, Column, Diagonal } from '../definitions';

export function getRows(grid: Grid): Row[] {
  const length = Math.sqrt(grid.length);
  const copy = grid.concat([]);
  return getArray(length).map(() => copy.splice(0, length));
}

export function getColumns(grid: Grid): Column[] {
  return getRows(transpose(grid));
}

export function getDiagonals(grid: Grid): Diagonal[] {
  // TODO: Make it work
  return [];
}

function getArray(length: number) {
  return Array.apply(null, { length }).map(Number.call, Number);
}

export function transpose<T>(grid: Array<T>): Array<T> {
  const size = Math.sqrt(grid.length);
  const transposed = grid.filter(() => false);
    for (let j = 0; j < size; ++j) {
        for (let i = 0; i < size; ++i) {
            transposed.push(grid[j + (i * size)]);
        }
    }
  return transposed;
}

import { Grid, Row, Column, Diagonal } from '../definitions';

export function getRows(grid: Grid): Row[] {
  const length = Math.sqrt(grid.length);
  const copy = grid.concat([]);
  return getArray(length).map(() => copy.splice(0, length));
}

export function getColumns(grid: Grid): Column[] {
  return getRows(transpose(grid));
}

export function getDiagonals(grid: Grid): Diagonal[] {
  // TODO: Make it work
  return [];
}

function getArray(length: number) {
  return Array.apply(null, { length }).map(Number.call, Number);
}

export function transpose<T>(grid: Array<T>): Array<T> {
  const size = Math.sqrt(grid.length);
  var transposed = grid.filter(() => false);
    for (let j = 0; j < size; ++j) {
        for (let i = 0; i < size; ++i) {
            transposed.push(grid[j + (i * size)]);
        }
    }
  return transposed;
}

--- 
+++ 
@@ -21,7 +21,7 @@
 
 export function transpose<T>(grid: Array<T>): Array<T> {
   const size = Math.sqrt(grid.length);
-  var transposed = grid.filter(() => false);
+  const transposed = grid.filter(() => false);
     for (let j = 0; j < size; ++j) {
         for (let i = 0; i < size; ++i) {
             transposed.push(grid[j + (i * size)]);
Use const instead of var
