From 83b32e4170283d5759468251f2ce785803992618 Mon Sep 17 00:00:00 2001
From: Inanc Gumus <m@inanc.io>
Date: Mon, 2 Sep 2019 16:48:38 +0300
Subject: [PATCH] update: interface promoted methods

---
 .../book.go                                         |  0
 .../game.go                                         |  0
 .../list.go                                         | 13 ++++---------
 .../main.go                                         |  0
 .../money.go                                        |  0
 .../product.go                                      |  0
 .../puzzle.go                                       |  0
 .../toy.go                                          |  0
 8 files changed, 4 insertions(+), 9 deletions(-)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/book.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/game.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/list.go (73%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/main.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/money.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/product.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/puzzle.go (100%)
 rename interfaces/{08-method-embedding => 08-promoted-methods}/toy.go (100%)

diff --git a/interfaces/08-method-embedding/book.go b/interfaces/08-promoted-methods/book.go
similarity index 100%
rename from interfaces/08-method-embedding/book.go
rename to interfaces/08-promoted-methods/book.go
diff --git a/interfaces/08-method-embedding/game.go b/interfaces/08-promoted-methods/game.go
similarity index 100%
rename from interfaces/08-method-embedding/game.go
rename to interfaces/08-promoted-methods/game.go
diff --git a/interfaces/08-method-embedding/list.go b/interfaces/08-promoted-methods/list.go
similarity index 73%
rename from interfaces/08-method-embedding/list.go
rename to interfaces/08-promoted-methods/list.go
index ec401e1..381de50 100644
--- a/interfaces/08-method-embedding/list.go
+++ b/interfaces/08-promoted-methods/list.go
@@ -9,11 +9,12 @@ package main
 
 import "fmt"
 
-type printer interface {
+type item interface {
 	print()
+	discount(float64)
 }
 
-type list []printer
+type list []item
 
 func (l list) print() {
 	if len(l) == 0 {
@@ -27,13 +28,7 @@ func (l list) print() {
 }
 
 func (l list) discount(ratio float64) {
-	type discounter interface {
-		discount(float64)
-	}
-
 	for _, it := range l {
-		if it, ok := it.(discounter); ok {
-			it.discount(ratio)
-		}
+		it.discount(ratio)
 	}
 }
diff --git a/interfaces/08-method-embedding/main.go b/interfaces/08-promoted-methods/main.go
similarity index 100%
rename from interfaces/08-method-embedding/main.go
rename to interfaces/08-promoted-methods/main.go
diff --git a/interfaces/08-method-embedding/money.go b/interfaces/08-promoted-methods/money.go
similarity index 100%
rename from interfaces/08-method-embedding/money.go
rename to interfaces/08-promoted-methods/money.go
diff --git a/interfaces/08-method-embedding/product.go b/interfaces/08-promoted-methods/product.go
similarity index 100%
rename from interfaces/08-method-embedding/product.go
rename to interfaces/08-promoted-methods/product.go
diff --git a/interfaces/08-method-embedding/puzzle.go b/interfaces/08-promoted-methods/puzzle.go
similarity index 100%
rename from interfaces/08-method-embedding/puzzle.go
rename to interfaces/08-promoted-methods/puzzle.go
diff --git a/interfaces/08-method-embedding/toy.go b/interfaces/08-promoted-methods/toy.go
similarity index 100%
rename from interfaces/08-method-embedding/toy.go
rename to interfaces/08-promoted-methods/toy.go