Java05. ДЗ 03, Васильев Роман

.gitignore

@@ -3,6 +3,10 @@
 # Mobile Tools for Java (J2ME)
 .mtj.tmp/
 
+*.iml
+build/*
+.idea/*
+
 # Package Files #
 *.jar
 *.war

build.gradle

@@ -0,0 +1,12 @@
+group 'org'
+version '1.0-SNAPSHOT'
+
+apply plugin: 'java'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testCompile group: 'junit', name: 'junit', version: '4.12'
+}

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Sun Feb 14 15:03:16 MSK 2016
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.5-bin.zip

settings.gradle

@@ -0,0 +1,2 @@
+rootProject.name = 'task'
+

src/main/java/task/Collections.java

@@ -0,0 +1,60 @@
+package task;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+
+public class Collections {
+
+    public static <X, Y> List<Y> map(Function1<? super X, Y> f, Iterable<X> a) {
+        List<Y> list = new LinkedList<>();
+        for (X x : a) {
+            list.add(f.apply(x));
+        }
+        return list;
+    }
+
+    public static <X> List<X> filter(Predicate<? super X> p, Iterable<X> a) {
+        List<X> list = new LinkedList<>();
+        for (X x : a) {
+            if (p.apply(x)) {
+                list.add(x);
+            }
+        }
+        return list;
+    }
+
+    public static <X> List<X> takeWhile(Predicate<? super X> p, Iterable<X> a) {
+        List<X> list = new LinkedList<>();
+        for (X x : a) {
+            if (!p.apply(x)) break;
+            list.add(x);
+        }
+        return list;
+    }
+
+    public static <X> List<X> takeUnless(Predicate<? super X> p, Iterable<X> a) {
+        return takeWhile(p.not(), a);
+    }
+
+    public static <X, Y> Y foldr(Function2<? super Y, ? super X, Y> f, Y base, Iterable<X> a) {
+        return myFoldr(f, base, a.iterator());
+    }
+
+    public static <X, Y> Y foldl(Function2<? super Y, ? super X, Y> f, Y base, Iterable<X> a) {
+        for (X x : a) {
+            base = f.apply(base, x);
+        }
+        return base;
+    }
+
+    private static <X, Y> Y myFoldr(Function2<? super Y, ? super X, Y> f, Y base, Iterator<X> a) {
+        if (!a.hasNext()) {
+            return base;
+        } else {
+            X x = a.next();
+            return f.apply(myFoldr(f, base, a), x);
+        }
+    }
+}

src/main/java/task/Function1.java

@@ -0,0 +1,21 @@
+package task;
+
+
+public abstract class Function1<X, Y> {
+    public abstract Y apply(X x);
+
+    public <Z> Function1<X, Z> compose(Function1<? super Y, Z> other) {
+        Function1<X, Y> self = this;
+        return new Function1<X, Z>() {
+            private final Function1<X, Y> f = self;
+            private final Function1<? super Y, Z> g = other;
+
+            @Override
+            public Z apply(X x) {
+                return g.apply(f.apply(x));
+            }
+        };
+    }
+
+
+}