j -> json

This name needs to be consistent as of Swift 3, so we should be consistent in
our documentation.

Documentation/Compilation-Errors.md

@@ -19,11 +19,11 @@ Fortunately this is easy to solve. A first step is to store
 `curry(Model.init)` in a variable instead of using it directly:
 
 ```swift
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  let create = curry(Model.init)
  return create
- <^> j <| "key1"
- <*> j <| "key2"
+ <^> json <| "key1"
+ <*> json <| "key2"
  ...
 ```
 
@@ -32,15 +32,15 @@ issues, the next step is to pick a midpoint in your decoding chain and set an
 intermediate variable:
 
 ```swift
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  let create = curry(Model.init)
  let tmp = create
- <^> j <| "key_a_1"
- <*> j <| "key_a_2"
+ <^> json <| "key_a_1"
+ <*> json <| "key_a_2"
  ...
  return tmp
- <*> j <| "key_b_1"
- <*> j <| "key_b_2"
+ <*> json <| "key_b_1"
+ <*> json <| "key_b_2"
  ...
 ```
 
@@ -90,18 +90,18 @@ likely means that you are using `<*>` when you should be using `<^>`:
 
 ```swift
 // Correct
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  return curry(Model.init)
- <^> j <| "key1" // <-- Good
- <*> j <| "key2"
+ <^> json <| "key1" // <-- Good
+ <*> json <| "key2"
  ...
 }
 
 // Incorrect
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  return curry(Model.init)
- <*> j <| "key1" // <-- Bad
- <*> j <| "key2"
+ <*> json <| "key1" // <-- Bad
+ <*> json <| "key2"
  ...
 }
 ```
@@ -121,18 +121,18 @@ used the map operator `<^>` instead of the applicative operator `<*>`:
 
 ```swift
 // Correct
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  return curry(Model.init)
- <^> j <| "key1"
- <*> j <| "key2" // <-- Good
+ <^> json <| "key1"
+ <*> json <| "key2" // <-- Good
  ...
 }
 
 // Incorrect
-static func decode(j: JSON) -> Decoded<Model> {
+static func decode(json: JSON) -> Decoded<Model> {
  return curry(Model.init)
- <^> j <| "key1"
- <^> j <| "key2" // <-- Bad
+ <^> json <| "key1"
+ <^> json <| "key2" // <-- Bad
  ...
 }
 ```