Add strategy.

README.md

@@ -9,7 +9,7 @@
 
 |项目|描述|
 |:-:|:-:|
-|版本：|0.0.21|
+|版本：|0.0.22|
 |作者：|左志华（zoziha）|
 |网页：|https://zoziha.github.io/Fortran-Design-Patterns/|
 |版权：|Copyright (c) 2021 zoziha|
@@ -19,6 +19,7 @@
 ### 软件依赖
 
 - Git
+- [fortran-lang/fpm](https://github.com/fortran-lang/fpm)
 - [Rust](https://www.rust-lang.org/zh-CN/)
 - [mdbook](https://github.com/rust-lang/mdBook)
 

doc/src/Introduction.md

@@ -16,8 +16,7 @@ Fortran三种编程范式：https://zhuanlan.zhihu.com/p/412243161
 
 |状态|创建型模式|结构型模式|行为模式|
 |:-:|:-:|:-:|:-:|
-|完成|抽象工厂、生成器、工厂方法、原型、单例。|适配器、桥接、组合、装饰、外观、代理、享元。|责任链、命令、迭代器、观察者、状态、模板方法、备忘录、中介者、访问者。|
-|未完成|||策略。|
+|完成|抽象工厂、生成器、工厂方法、原型、单例。|适配器、桥接、组合、装饰、外观、代理、享元。|责任链、命令、迭代器、观察者、状态、模板方法、备忘录、中介者、访问者、策略。|
 
 #### 创建型模式
 
@@ -46,6 +45,6 @@ Fortran三种编程范式：https://zhuanlan.zhihu.com/p/412243161
 - [X] 备忘录
 - [X] 观察者
 - [X] 状态
-- [ ] 策略
+- [X] 策略
 - [X] 模板方法
 - [X] 访问者

doc/src/SUMMARY.md

@@ -30,6 +30,7 @@
   - [中介者模式](behavioral/mediator.md)
   - [备忘录模式](behavioral/memento.md)
   - [状态模式](behavioral/state.md)
+  - [策略模式](behavioral/strategy.md)
   - [模板方法模式](behavioral/template-method.md)
   - [访问者模式](behavioral/visitor.md)
 

doc/src/behavioral/strategy.md

@@ -0,0 +1,13 @@
+# 策略模式
+
+正文：https://refactoringguru.cn/design-patterns/strategy
+
+Go代码：https://refactoringguru.cn/design-patterns/strategy/go/example
+
+```fortran
+{{#include ../../../src/behavioral/strategy/strategy_module.f90}}
+```
+
+```fortran
+{{#include ../../../src/behavioral/strategy/strategy_main.f90}}
+```

fpm.toml

@@ -1,4 +1,10 @@
 name = "Fortran-Design-Patterns"
+version = "0.0.22"
+license = "BSD-3"
+maintainer = "左志华"
+copyright = "Copyright 2021 左志华"
+description = "Fortran Design Patterns"
+categories = ["Demo", "OOP", "Modern Fortran"]
 
 [library]
 source-dir = "src"
@@ -41,6 +47,11 @@ name = "state"
 source-dir = "src/behavioral/state"
 main = "state_main.f90"
 
+[[test]]
+name = "strategy"
+source-dir = "src/behavioral/strategy"
+main = "strategy_main.f90"
+
 [[test]]
 name = "template_method"
 source-dir = "src/behavioral/template-method"

src/behavioral/strategy/strategy_main.f90

@@ -0,0 +1,20 @@
+program strategy_main
+
+    use strategy_module, only: add_t, sub_t, calculator_t
+    implicit none
+    type(add_t) :: add
+    type(sub_t) :: sub
+    type(calculator_t) :: calculator
+
+    call calculator%set_strategy(add)
+    print *, "Add:", calculator%strategy%calc(1, 1)
+
+    call calculator%set_strategy(sub)
+    print *, "Sub:", calculator%strategy%calc(1, 1)
+
+end program strategy_main
+
+!> Results shall be:
+
+!  Add:           2
+!  Sub:           0

src/behavioral/strategy/strategy_module.f90

@@ -0,0 +1,64 @@
+module strategy_module
+
+    implicit none
+    private
+
+    public :: add_t, sub_t, calculator_t
+
+    type, abstract :: strategy_t
+    contains
+        procedure(strategy_t_calc), deferred :: calc
+    end type strategy_t
+
+    abstract interface
+        integer function strategy_t_calc(self, a, b) result(c)
+            import strategy_t
+            class(strategy_t), intent(inout) :: self
+            integer, intent(in) :: a, b
+        end function strategy_t_calc
+    end interface
+
+    type, extends(strategy_t) :: add_t
+    contains
+        procedure :: calc => add_t_calc
+    end type add_t
+
+    type, extends(strategy_t) :: sub_t
+    contains
+        procedure :: calc => sub_t_calc
+    end type sub_t
+
+    type calculator_t
+        class(strategy_t), pointer :: strategy
+    contains
+        procedure :: set_strategy => calculator_t_set_strategy
+        procedure :: get_result => calculator_t_get_result
+    end type calculator_t
+
+contains
+
+    integer function add_t_calc(self, a, b) result(c)
+        class(add_t), intent(inout) :: self
+        integer, intent(in) :: a, b
+        c = a + b
+    end function add_t_calc
+
+    integer function sub_t_calc(self, a, b) result(c)
+        class(sub_t), intent(inout) :: self
+        integer, intent(in) :: a, b
+        c = a - b
+    end function sub_t_calc
+
+    subroutine calculator_t_set_strategy(self, strategy)
+        class(calculator_t), intent(inout) :: self
+        class(strategy_t), intent(in), target :: strategy
+        self%strategy => strategy
+    end subroutine calculator_t_set_strategy
+
+    integer function calculator_t_get_result(self, a, b) result(c)
+        class(calculator_t), intent(inout) :: self
+        integer, intent(in) :: a, b
+        c = self%strategy%calc(a, b)
+    end function calculator_t_get_result
+
+end module strategy_module