再次小结领域模型的种种观点

script:

define function sum(x,y); as{ x+y*2+1+4/2};
define function anoSum(x); as{ x*sum(x,x+1); );;

//retrieve parsed function
Func func = engine.parse(scirptPath);.getFunction("anoSum");;
//input the param

Object result = func.addArgument(1);.getResult(engine);;

assertEquals(new Double(8);,result);;

define function F(x);  as{ 
if(x==0);{1} 
else{x*F(x-1); }

 }

F(x); =  {x==0: 1} or { x*F(x-1);}

define func1(x,y); as {..}

define func1(x); as {...}

define func3(x,y); as {...}
define func(); as{  
 func3(func1(1,2);,func2(3); );+2+3 }

do
  v1<- rule1
  v2 <- rule2
  return (v1>v2);

do
  v1<- rule1
  v2 <- rule2
  return (v1>v2);

4。强类型？动态类型？
5。语言有没有java规范内的动态语义？比如你在script里面写个1，它输出到java里是Integer? Long？ BigInteger?

6。支持什么样的数据结构？list？hashtable？string？regular expression？tuple？

define list as {class:jfun.fp.listFunc};
define tail as{class:jfun.fp.tailList};
define head as {class:jfrun.fp.HeadList};

define func1(); as{ tail(list(1,2,3,4););++list(5,6); };
将返回list ,(2,3,4,5,6);.

final_discount where
  Calendar = jaskell.java.import "java.util.Calendar";
  isMonth m = eq(m, cre.datepart "MONTH");;
  isDay d = eq(d, cre.datepart "DAY_OF_MONTH");;
  purchase ctxt = ctxt.getPurchasedProducts[];
  purchased product = do {products=purchase} $
    products.contains[product];
  purchased_all products = cre.and(jaskell.prelude.map purchased products);;
  discount d = return (1-d);;
  cardtype ctxt = ctxt.getCardType[];
  gender ctxt = ctxt.getGender[];
  discountByMember type v = (eq type cardtype);.then (discount v);;
  gold_member = discountByMember "gold" 0.1;
  silver_member = discountByMember "silver" 0.05;
  platinum_member = discountByMember "platinum" 0.2;
  by_member = cre.any[platinum_member, gold_member, silver_member];
  is_female = eq "female" gender;
  is_female_day = cre.and[isMonth(Calendar.MARCH);, isDay 8];
  female_discount = discount 0.05 `when cre.and[is_female, is_female_day];
  tvspeaker = discount 0.05 `when purchased_all["tv", "speaker"];
  tvspeakerdvd = discount 0.07 `when purchased_all["tv", "speaker", "dvd"];
  by_purchase = cre.any[tvspeakerdvd, tvspeaker];
  final_discount = cre.fold (*); 1 [by_member, female_discount, by_purchase];
end

右面表达式的值是一个高阶逻辑对象。而"<-"左边的符号代表的是这个高阶对象一旦运行所产生的结果。如果用"="，左边的符号才是这个表达式的值：那个高阶对象。

右面表达式的值是一个高阶逻辑对象。而"<-"左边的符号代表的是这个高阶对象一旦运行所产生的结果。如果用"="，左边的符号才是这个表达式的值：那个高阶对象。

那我所说的=就是指高阶对象运算产生的结果。  可能表达不大一致罢了 ，我理解的fp是没有引用赋值的概念的。
另外，看了你写的那个脚本，感觉很难看懂。 语法不是很亲切，其实Hashkell的思想很好，但是语法不好，我觉得不应该再使用那种晦涩难懂的语法。
另外，关于java的函数组合，apache已经作了很多尝试，其中有一个已经成形的库:org.apache.commons.functor.

里面主要作了闭包，函数组合的封装。 全部是对象的方式。
主要作了可以传递函数对象的形式，并提供特有的绑定支持。部分实现currying功能。
这些都可以用来组合实现复杂的业务规则。

,以前没看过FP的东东，基础很差阿。很多东西理解错了，大家别笑话阿。 赫赫

 
private Rule getRule();{
   final Rule gold_member = MyRules.discountByMember("gold", 0.1);;
    final Rule silver_member = MyRules.discountByMember("silver", 0.05);;
    final Rule platinum_member = MyRules.discountByMember("platinum", 0.2);;
    final Rule by_member = MyRules.any(new Rule[]{platinum_member,
        gold_member, silver_member});;
   
   
   
    final Rule is_female = MyRules.isGender("female");;
    final Rule is_female_day = MyRules.isMonth(Calendar.MARCH);
        .and(MyRules.isDay(8););;
    final Rule female_discount = is_female.and(is_female_day);
        .then(MyRules.discount(0.05););;
   
   
   
    final Rule tvspeaker = MyRules.purchased(new String[]{"tv","speaker"});
        .then(MyRules.discount(0.05););;
    final Rule tvspeakerdvd = MyRules.purchased(new String[]{"tv","speaker","dvd"});
        .then(MyRules.discount(0.07););;
    final Rule by_purchase = MyRules.any(new Rule[]{tvspeakerdvd, tvspeaker});;
   
    final Rule final_discount = MyRules.productDouble(new Rule[]{
      by_member, female_discount, by_purchase
    });;
    return final_discount;
  }