Step 10: Generic F-program

47degrees · Jan 21, 2019 · b0d6d89 · b0d6d89
1 parent aebcf7d
commit b0d6d89
Showing 1 changed file with 24 additions and 23 deletions.
diff --git a/...Fundamentals/FPFundamentals.playground/Pages/Fundamentals.xcplaygroundpage/Contents.swift b/...Fundamentals/FPFundamentals.playground/Pages/Fundamentals.xcplaygroundpage/Contents.swift
@@ -26,42 +26,43 @@ struct Statement {
     let accounts: Int
 }
 
-class Program {
-    let getBank1Credentials: Option<String> = .some("MyUser_Password")
-    let moneyInPocket: Int = 20
+class Program<F, MonadF> where MonadF: Monad, MonadF.F == F {
+    let monad: MonadF
 
-    func getBalanceBank1(credentials: String) -> Option<Account> {
-        return .some(Account(id: "a1", balance: 100))
+    init(monad: MonadF) {
+        self.monad = monad
     }
 
-    let getBalanceBank2: Option<Int> = .some(80)
-
-    var b1: Option<Int> {
-        return Option<Any>.monad().flatMap(self.getBank1Credentials, { credentials in
-            Option<Any>.functor().map(self.getBalanceBank1(credentials: credentials), { acc in acc.balance }).fix()
-        }).fix()
+    var getBank1Credentials: Kind<F, String> {
+        return monad.pure("MyUser_Password")
     }
+    let moneyInPocket: Int = 20
 
-    var b2: Option<Int> { return self.getBalanceBank2 }
-
-    var p: Option<Int> {
-        return Option<Any>.applicative().pure(moneyInPocket).fix()
+    func getBalanceBank1(credentials: String) -> Kind<F, Account> {
+        return self.monad.pure(Account(id: "a1", balance: 100))
     }
 
-    var balance: Option<Int> {
-        let combinator = Option.semigroup(Int.sumSemigroup)
-        return combinator.combine(combinator.combine(b1, b2), p).fix()
+    var getBalanceBank2: Kind<F, Int> {
+        return self.monad.pure(80)
     }
 
-    var statement: Option<Statement> {
-        return Option<Any>.applicative().map2(b1, b2) { x, y in
-            Statement(isRich: (x + y > 1000), accounts: 2) }.fix()
+    var balance: Kind<F, Int> {
+        return monad.binding(
+            { self.getBank1Credentials },
+            { credentials in self.monad.map(self.getBalanceBank1(credentials: credentials), { acc in acc.balance }) },
+            { _, _ in self.getBalanceBank2 },
+            { _, _, _ in self.monad.pure(self.moneyInPocket) },
+            { _, b1, b2, p in self.monad.pure(b1 + b2 + p) }
+        )
     }
 
     func run() {
         print(balance)
-        print(statement)
     }
 }
 
-Program().run()
+Program(monad: Id<Any>.monad()).run()
+Program(monad: Option<Any>.monad()).run()
+Program(monad: Either<String, Any>.monad()).run()
+Program(monad: Try<Any>.monad()).run()
+Program(monad: ListK<Any>.monad()).run()