Use blocked scoped variables

In addition to using const and let, this also upgrades our linter config and removes lint (mostly whitespace).

src/ol/math.js

@@ -25,17 +25,17 @@ export function clamp(value, min, max) {
  * @param {number} x X.
  * @return {number} Hyperbolic cosine of x.
  */
-export var cosh  = (function() {
+export const cosh  = (function() {
   // Wrapped in a iife, to save the overhead of checking for the native
   // implementation on every invocation.
-  var cosh;
+  let cosh;
   if ('cosh' in Math) {
     // The environment supports the native Math.cosh function, use it…
     cosh = Math.cosh;
   } else {
     // … else, use the reference implementation of MDN:
     cosh = function(x) {
-      var y = Math.exp(x);
+      const y = Math.exp(x);
       return (y + 1 / y) / 2;
     };
   }
@@ -65,10 +65,10 @@ export function roundUpToPowerOfTwo(x) {
  * @return {number} Squared distance.
  */
 export function squaredSegmentDistance(x, y, x1, y1, x2, y2) {
-  var dx = x2 - x1;
-  var dy = y2 - y1;
+  const dx = x2 - x1;
+  const dy = y2 - y1;
   if (dx !== 0 || dy !== 0) {
-    var t = ((x - x1) * dx + (y - y1) * dy) / (dx * dx + dy * dy);
+    const t = ((x - x1) * dx + (y - y1) * dy) / (dx * dx + dy * dy);
     if (t > 1) {
       x1 = x2;
       y1 = y2;
@@ -90,8 +90,8 @@ export function squaredSegmentDistance(x, y, x1, y1, x2, y2) {
  * @return {number} Squared distance.
  */
 export function squaredDistance(x1, y1, x2, y2) {
-  var dx = x2 - x1;
-  var dy = y2 - y1;
+  const dx = x2 - x1;
+  const dy = y2 - y1;
   return dx * dx + dy * dy;
 }
 
@@ -104,14 +104,14 @@ export function squaredDistance(x1, y1, x2, y2) {
  * @return {Array.<number>} The resulting vector.
  */
 export function solveLinearSystem(mat) {
-  var n = mat.length;
+  const n = mat.length;
 
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     // Find max in the i-th column (ignoring i - 1 first rows)
-    var maxRow = i;
-    var maxEl = Math.abs(mat[i][i]);
-    for (var r = i + 1; r < n; r++) {
-      var absValue = Math.abs(mat[r][i]);
+    let maxRow = i;
+    let maxEl = Math.abs(mat[i][i]);
+    for (let r = i + 1; r < n; r++) {
+      const absValue = Math.abs(mat[r][i]);
       if (absValue > maxEl) {
         maxEl = absValue;
         maxRow = r;
@@ -123,14 +123,14 @@ export function solveLinearSystem(mat) {
     }
 
     // Swap max row with i-th (current) row
-    var tmp = mat[maxRow];
+    const tmp = mat[maxRow];
     mat[maxRow] = mat[i];
     mat[i] = tmp;
 
     // Subtract the i-th row to make all the remaining rows 0 in the i-th column
-    for (var j = i + 1; j < n; j++) {
-      var coef = -mat[j][i] / mat[i][i];
-      for (var k = i; k < n + 1; k++) {
+    for (let j = i + 1; j < n; j++) {
+      const coef = -mat[j][i] / mat[i][i];
+      for (let k = i; k < n + 1; k++) {
         if (i == k) {
           mat[j][k] = 0;
         } else {
@@ -141,10 +141,10 @@ export function solveLinearSystem(mat) {
   }
 
   // Solve Ax=b for upper triangular matrix A (mat)
-  var x = new Array(n);
-  for (var l = n - 1; l >= 0; l--) {
+  const x = new Array(n);
+  for (let l = n - 1; l >= 0; l--) {
     x[l] = mat[l][n] / mat[l][l];
-    for (var m = l - 1; m >= 0; m--) {
+    for (let m = l - 1; m >= 0; m--) {
       mat[m][n] -= mat[m][l] * x[l];
     }
   }
@@ -181,7 +181,7 @@ export function toRadians(angleInDegrees) {
  * @return {number} Modulo.
  */
 export function modulo(a, b) {
-  var r = a % b;
+  const r = a % b;
   return r * b < 0 ? r + b : r;
 }