#189: Replace anonymous P2 with static constructor

mperry · mperry · commit 92f663384541 · 2015-09-04T16:23:26.000+10:00
diff --git a/core/src/main/java/fj/P.java b/core/src/main/java/fj/P.java
@@ -233,6 +233,10 @@ public H _8() {
         };
     }
 
+    public static <A, B> P2<A, B> lazyProduct(F0<P2<A, B>> f) {
+        return P.lazy(() -> f.f()._1(), () -> f.f()._2());
+    }
+
     /**
    * A function that puts an element in a product-2.
    *
@@ -548,16 +552,7 @@ public static <A> P1<A> lazy(F<Unit, A> f) {
     }
 
     public static <A, B> P2<A, B> lazy(F<Unit, A> fa, F<Unit, B> fb) {
-        return new P2<A, B>() {
-            @Override
-            public A _1() {
-                return fa.f(unit());
-            }
-            @Override
-            public B _2() {
-                return fb.f(unit());
-            }
-        };
+        return P.lazy(() -> fa.f(unit()), () -> fb.f(unit()));
     }
 
     public static <A, B, C> P3<A, B, C> lazy(F<Unit, A> fa, F<Unit, B> fb, F<Unit, C> fc) {
diff --git a/core/src/main/java/fj/P2.java b/core/src/main/java/fj/P2.java
@@ -42,15 +42,7 @@ public int hashCode() {
    * @return A new product-2 with the elements swapped.
    */
   public final P2<B, A> swap() {
-    return new P2<B, A>() {
-      public B _1() {
-        return P2.this._2();
-      }
-
-      public A _2() {
-        return P2.this._1();
-      }
-    };
+      return P.lazy(() -> P2.this._2(), () -> P2.this._1());
   }
 
   /**
@@ -60,15 +52,8 @@ public A _2() {
    * @return A product with the given function applied.
    */
   public final <X> P2<X, B> map1(final F<A, X> f) {
-    return new P2<X, B>() {
-      public X _1() {
-        return f.f(P2.this._1());
-      }
-
-      public B _2() {
-        return P2.this._2();
-      }
-    };
+      P2<A, B> self = this;
+      return P.lazy(() -> f.f(self._1()), () -> self._2());
   }
 
   /**
@@ -78,15 +63,7 @@ public B _2() {
    * @return A product with the given function applied.
    */
   public final <X> P2<A, X> map2(final F<B, X> f) {
-    return new P2<A, X>() {
-      public A _1() {
-        return P2.this._1();
-      }
-
-      public X _2() {
-        return f.f(P2.this._2());
-      }
-    };
+      return P.lazy(() -> P2.this._1(), () -> f.f(P2.this._2()));
   }
 
 
@@ -112,16 +89,8 @@ public final <C, D> P2<C, D> split(final F<A, C> f, final F<B, D> g) {
    *         and with the second element intact.
    */
   public final <C> P2<C, B> cobind(final F<P2<A, B>, C> k) {
-    return new P2<C, B>() {
-
-      public C _1() {
-        return k.f(P2.this);
-      }
-
-      public B _2() {
-        return P2.this._2();
-      }
-    };
+      P2<A, B> self = this;
+      return P.lazy(() -> k.f(self), () -> self._2());
   }
 
   /**
diff --git a/core/src/main/java/fj/Semigroup.java b/core/src/main/java/fj/Semigroup.java
@@ -316,15 +316,7 @@ public static <A> Semigroup<P1<A>> p1Semigroup(final Semigroup<A> sa) {
    * @return A semigroup for binary products.
    */
   public static <A, B> Semigroup<P2<A, B>> p2Semigroup(final Semigroup<A> sa, final Semigroup<B> sb) {
-    return semigroup((a1, a2) -> new P2<A, B>() {
-      public A _1() {
-        return sa.sum(a1._1(), a2._1());
-      }
-
-      public B _2() {
-        return sb.sum(a1._2(), a2._2());
-      }
-    });
+      return semigroup((a1, a2) -> P.lazy(() -> sa.sum(a1._1(), a2._1()), () -> sb.sum(a1._2(), a2._2())));
   }
 
   /**
diff --git a/core/src/main/java/fj/data/Stream.java b/core/src/main/java/fj/data/Stream.java
@@ -1085,15 +1085,10 @@ public final P2<Stream<A>, Stream<A>> span(final F<A, Boolean> p) {
       return p(this, this);
     else if (p.f(head())) {
       final P1<P2<Stream<A>, Stream<A>>> yszs = P.lazy(() -> tail()._1().span(p));
-      return new P2<Stream<A>, Stream<A>>() {
-        @Override public Stream<A> _1() {
-          return cons(head(), yszs.map(P2.<Stream<A>, Stream<A>>__1()));
-        }
-
-        @Override public Stream<A> _2() {
-          return yszs._1()._2();
-        }
-      };
+      return P.lazy(
+            () -> cons(head(), yszs.map(P2.<Stream<A>, Stream<A>>__1())),
+            () -> yszs._1()._2()
+        );
     } else
       return p(Stream.<A>nil(), this);
   }
diff --git a/core/src/main/java/fj/data/vector/V.java b/core/src/main/java/fj/data/vector/V.java
@@ -36,15 +36,7 @@ public static <A> V2<A> v(final A a1, final A a2) {
    * @return The vector-2.
    */
   public static <A> V2<A> v(final F0<A> a1, final F0<A> a2) {
-    return V2.p(new P2<A, A>() {
-      public A _1() {
-        return a1.f();
-      }
-
-      public A _2() {
-        return a2.f();
-      }
-    });
+      return V2.p(P.lazy(() -> a1.f(), () -> a2.f()));
   }
 
   /**
diff --git a/core/src/main/java/fj/data/vector/V3.java b/core/src/main/java/fj/data/vector/V3.java
@@ -32,16 +32,7 @@ private V3(final P1<A> head, final V2<A> tail) {
   public static <A> V3<A> p(final P3<A, A, A> p) {
     return new V3<A>(
         P.lazy(() -> p._1()),
-        V2.p(new P2<A, A>() {
-              public A _1() {
-                return p._2();
-              }
-
-              public A _2() {
-                return p._3();
-              }
-        }
-        )
+        V2.p(P.lazy(() -> p._2(), () -> p._3()))
     );
   }
 
