Merge branch 'master' into typos

ch-11.md

@@ -22,7 +22,13 @@ const fold = f => acc => ([x, ...xs]) =>
  ? acc
  : f(fold(f) (acc) (xs)) (x);
 
-const xs = [1,2,3];
+const map = f => fold(acc => x =>
+ arrCons_(acc) (f(x)))
+ ([]);
+
+const sqr = x => x * x;
+
+const xs = [1, 2, 3];
 
 const main = map(sqr);
 
@@ -88,7 +94,16 @@ const fold = f => acc => ([x, ...xs]) =>
  ? acc
  : f(fold(f) (acc) (xs)) (x);
 
-const xs = [1,2,3];
+const map = f => xs => fold(acc => x =>
+// ^^^^^
+ arrCons_(acc) (f(x)))
+ ([])
+ (xs);
+// ^^^^
+
+const sqr = x => x * x;
+
+const xs = [1, 2, 3];
 
 const main = map(sqr);