add usage paraprah

Author: sensorario

README.md

@@ -1,7 +1,7 @@
 # Go Design Patterns
 
 ## [Creational](creational)
- 
+
  * [Abstract Factory method](creational/abstract_factory) [:notebook:](http://en.wikipedia.org/wiki/Abstract_Factory_pattern)
  * [Builder](creational/builder) [:notebook:](http://en.wikipedia.org/wiki/Builder_pattern)
  * [Factory method](creational/factory) [:notebook:](http://en.wikipedia.org/wiki/Factory_pattern)

creational/abstract_factory/README.md

@@ -21,3 +21,26 @@ func TestFoo(t *testing.T) {
 	t.Logf("%v car has %d wheels", car.GetModelName(), car.NumOfWheels())
 }
 ```
+
+## Usage
+
+BuildFactory provide a factory of italian cars. Then italian builder build a particular model of car. This model must have 4 wheels.
+
+```go
+fca, _ := BuildFactory(ItalianType)
+m, _ := fca.Build(FerrariModel)
+car, err := m.(Vehicle)
+if model.NumOfWheels() != 4 {
+  panic("Ferrari shoud have 4 wheels")
+}
+```
+
+BuildFactory provide a factory of italian cars. Then italian builder build a particular model of car. This model must have 5 wheels.
+
+```go
+fca, _ := BuildFactory(ItalianType)
+model, _ := fca.Build(CarWithFiveWheelModel)
+if model.NumOfWheels() != 5 {
+  panic("the car should have 5 wheels")
+}
+```

creational/builder/README.md

@@ -110,3 +110,25 @@ func (c *BiciclettaBuilder) Build() Product {
 	return c.p
 }
 ```
+
+## Usage
+
+The director must build a vehicle like a car. Once the builder is provided. The director ask the builder to build the car. Finally we'll have right model of car.
+
+```go
+director := ManufacturingDirector{}
+
+carBuilder := &CarBuilder{}
+director.SetBuilder(carBuilder)
+director.Construct()
+car := carBuilder.Build()
+```
+
+The director must build a vehicle like a bike. Once the builder is provided. The director ask the builder to build the bike. Finally we'll have right model of bike.
+
+```go
+biciclettaBuilder := &BiciclettaBuilder{}
+director.SetBuilder(biciclettaBuilder)
+director.Construct()
+bike := biciclettaBuilder.Build()
+```

creational/pool/README.md

@@ -73,3 +73,20 @@ func (p *Pool) Receive(object PoolObject) {
 	}
 }
 ```
+
+## Usage
+
+First, the pool provide two object. Second, the pool receive one used object. Third, another loan is requested but instead of provide another instance of new object, thirdObject contains firstObject. No time is spent to build another object.
+
+```go
+pool := InitPool()
+firstObject := pool.Loan()
+secondObject := pool.Loan()
+
+pool.Receive(firstObject)
+thirdObject := pool.Loan()
+
+if firstObject.id != thirdObject.id {
+  panic("thir object must contain firs one")
+}
+```

creational/prototype/README.md

@@ -25,3 +25,16 @@ if thirdInstance.NumberOfCalls() != 3 {
 ## Few words …
 
 Is not good pattern if used to bring the state of the applicatoin and can cnange during its lifecycle. Making something global to avoid passing it around is a code smell. But use it to read configuration is good. Used to load a resource just first time is requested and to provide that resource everywere is a good way to use this pattern.
+
+## Usage
+
+Two kind of t-shirt are needed. Same model, with different SKU. Instead of recreeate same white shirt from scratch, base model is cloned.
+
+```go
+shirtCache := GetShirtsCloner()
+firstItem, err := shirtCache.GetClone(White)
+firstItem.SKU = "abc"
+
+secondItem, err := shirtCache.GetClone(White)
+secondItem.SKU = "xxx"
+```