Java 01. ДЗ 05. Малютина Катя, подгруппа 2

.gitignore

@@ -1,7 +1,6 @@
 *.class
 
 # Package Files #
-*.jar
 *.war
 *.ear
 
@@ -10,5 +9,7 @@
 *.ipr
 *.iws
 .idea/
+.gradle/
 
 target/**
+build/

Functional/build.gradle

@@ -0,0 +1,14 @@
+group 'ru.spbau.mit'
+version '1.0-SNAPSHOT'
+
+apply plugin: 'java'
+
+sourceCompatibility = 1.8
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testCompile group: 'junit', name: 'junit', version: '4.11'
+}

Functional/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Fri Mar 31 10:57:50 MSK 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.1-all.zip

Functional/settings.gradle

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

Functional/src/main/java/ru/spbau/mit/Collections.java

@@ -0,0 +1,67 @@
+package ru.spbau.mit;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+public final class Collections {
+
+    public static <T, R>
+    List<R> map(Function1<? super T, R> f, Iterable<T> a) {
+        List<R> res = new ArrayList<>();
+        for (T item : a) {
+            res.add(f.apply(item));
+        }
+        return res;
+    }
+
+    public static <T>
+    List<T> filter(Predicate<? super T> p, Iterable<T> a) {
+        List<T> result = new ArrayList<T>();
+        for (T item : a) {
+            if (p.apply(item)) {
+                result.add(item);
+            }
+        }
+        return result;
+    }
+
+    public static <T>
+    List<T> takeWhile(Predicate<? super T> p, Iterable<T> a) {
+        List<T> result = new ArrayList<>();
+        for (T element : a) {
+            if (!p.apply(element)) {
+                break;
+            }
+            result.add(element);
+        }
+        return result;
+    }
+
+    public static <T>
+    List<T> takeUnless(Predicate<? super T> p, Iterable<T> a) {
+        return takeWhile(p.not(), a);
+    }
+
+    public static <T1, T2>
+    T2 foldl(Function2<? super T2, ? super T1, T2> f, T2 begin, Iterable<T1> a) {
+        T2 result = begin;
+        for (T1 item : a) {
+            result = f.apply(result, item);
+        }
+        return result;
+    }
+
+    public static <T1, T2>
+    T2 foldr(Function2<? super T1, ? super T2, T2> f, T2 begin, Iterable<T1> a) {
+        LinkedList<T1> list = new LinkedList<>();
+        for (T1 item : a) {
+            list.addFirst(item);
+        }
+        T2 result = begin;
+        for (T1 item : list) {
+            result = f.apply(item, result);
+        }
+        return result;
+    }
+}

Functional/src/main/java/ru/spbau/mit/Function1.java

@@ -0,0 +1,16 @@
+package ru.spbau.mit;
+
+abstract class Function1<T, R> {
+
+    public abstract R apply(T t);
+
+    public <R2>
+    Function1<T, R2> compose(final Function1<? super R, R2> g) {
+        return new Function1<T, R2>() {
+            @Override
+            public R2 apply(T t) {
+                return g.apply(Function1.this.apply(t));
+            }
+        };
+    }
+}