fix: coding style and file format for chapter 11, 12, 13, 14 and 15.

eBook/exercises/chapter_11/interfaces_ext.go

@@ -1,51 +1,52 @@
-package main
-
-import "fmt"
-
-type Square struct {
-	side float32
-}
-
-type Triangle struct {
-	base   float32
-	height float32
-}
-
-type AreaInterface interface {
-	Area() float32
-}
-
-type PeriInterface interface {
-	Perimeter() float32
-}
-func main() {
-	var areaIntf AreaInterface
-	var periIntf PeriInterface
-
-	sq1 := new(Square)
-	sq1.side = 5
-	tr1 := new(Triangle)
-	tr1.base = 3
-	tr1.height = 5
-
-	areaIntf = sq1
-	fmt.Printf("The square has area: %f\n", areaIntf.Area())
-
-	periIntf = sq1
-	fmt.Printf("The square has perimeter: %f\n", periIntf.Perimeter())
-
-	areaIntf = tr1
-	fmt.Printf("The triangle has area: %f\n", areaIntf.Area())
-}
-
-func (sq *Square) Area() float32 {
-	return sq.side * sq.side
-}
-
-func (sq *Square) Perimeter() float32 {
-	return 4 * sq.side
-}
-
-func (tr *Triangle) Area() float32 {
-	return 0.5 * tr.base*tr.height
-}
+package main
+
+import "fmt"
+
+type Square struct {
+	side float32
+}
+
+type Triangle struct {
+	base   float32
+	height float32
+}
+
+type AreaInterface interface {
+	Area() float32
+}
+
+type PeriInterface interface {
+	Perimeter() float32
+}
+
+func main() {
+	var areaIntf AreaInterface
+	var periIntf PeriInterface
+
+	sq1 := new(Square)
+	sq1.side = 5
+	tr1 := new(Triangle)
+	tr1.base = 3
+	tr1.height = 5
+
+	areaIntf = sq1
+	fmt.Printf("The square has area: %f\n", areaIntf.Area())
+
+	periIntf = sq1
+	fmt.Printf("The square has perimeter: %f\n", periIntf.Perimeter())
+
+	areaIntf = tr1
+	fmt.Printf("The triangle has area: %f\n", areaIntf.Area())
+}
+
+func (sq *Square) Area() float32 {
+	return sq.side * sq.side
+}
+
+func (sq *Square) Perimeter() float32 {
+	return 4 * sq.side
+}
+
+func (tr *Triangle) Area() float32 {
+	return 0.5 * tr.base * tr.height
+}