добавлен "Список"

src/Lists.php

@@ -0,0 +1,108 @@
+<?php
+
+namespace Lists;
+use function Pairs\cons;
+use function Pairs\car;
+use function Pairs\cdr;
+use function Pairs\toString;
+
+
+/**
+ * применяет callable-функцию $func к списку $list
+ * @method map
+ * @param  callable $func функция
+ * @param  callable $list список
+ * @return [type]         [description]
+ */
+function map(callable $func, callable $list) {
+    $map = function ($items, $acc) use (&$map, $func) {
+        if (is_null($items)) {
+            return reverse($acc);
+        }
+        return $map(cdr($items), cons($func(car($items)), $acc));
+    };
+
+    return $map($list, null);
+}
+
+/**
+ * фильтрует список с помощью callable-функции
+ * @method filter
+ * @param  callable $func функция
+ * @param  callable $list список
+ * @return [type]         [description]
+ */
+function filter(callable $func, callable $list) {
+    $map = function ($func, $items) use (&$map) {
+        if ($items === null) {
+            return null;
+        } else {
+            $curr = car($items);
+            $rest = $map($func, cdr($items));
+            // filter
+            return $func($curr) ? cons($curr, $rest) : $rest;
+        }
+    };
+
+    return $map($func, $list);
+}
+
+/**
+ * сворачивает список с помощью callable-функции
+ * @method reduce
+ * @param  callable $func функция
+ * @param  callable $list список
+ * @param  mixed   $acc
+ * @return [type]         [description]
+ */
+function reduce(callable $func, callable $list, $acc = null) {
+    $iter = function ($items, $acc) use (&$iter, $func) {
+        return is_null($items) ? $acc : $iter(cdr($items), $func(car($items), $acc));
+    };
+
+    return $iter($list, $acc);
+}
+
+/**
+ * соединяет два списка
+ * @method append
+ * @param  pair $list1
+ * @param  pair $list2
+ * @return новый список
+ */
+function append(callable $list1, callable $list2)
+{
+     if ($list1 === null) {
+        return $list2;
+    } else {
+        return cons(car($list1), append(cdr($list1), $list2));
+    }
+}
+
+/**
+ * переворачивает список
+ * @method reverse
+ * @param  callable $list список
+ * @return перевернутый список
+ */
+function reverse(callable $list) {
+    $iter = function ($items, $acc) use (&$iter) {
+        return is_null($items) ? $acc : $iter(cdr($items), cons(car($items), $acc));
+    };
+
+    return $iter($list, null);
+}
+
+/**
+ * возвращает длинну списка
+ * @method length
+ * @param  callable $list список
+ * @return integer        длинна списка
+ */
+function length($list) {
+    if ($list === null || !is_callable($list)) {
+        return 0;
+    } else {
+        return 1 + length(cdr($list));
+    }
+}

src/Pairs.php

@@ -33,7 +33,7 @@ function toString($list)
     $arr = [];
     $iter = function ($items) use (&$arr, &$iter) {
         if ($items != null) {
-            $arr[] = listToString(car($items));
+            $arr[] = toString(car($items));
             $iter(cdr($items));
         }
 

tests/ListsTest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Pairs\tests;
+
+
+use function Pairs\cons;
+use function Pairs\car;
+use function Pairs\cdr;
+use function Pairs\toString;
+
+
+use function Lists\length;
+use function Lists\reverse;
+use function Lists\map;
+use function Lists\filter;
+use function Lists\reduce;
+
+class ListsTest extends \PHPUnit_Framework_TestCase
+{
+    public function testPairs()
+    {
+        $pair = cons(1, 2);
+        $this->assertEquals(1, car($pair));
+        $this->assertEquals(2, cdr($pair));
+    }
+
+    public function testLength()
+    {
+        $list = cons(1,cons(2, cons(3, null)));
+        $this->assertEquals(3, length($list));
+
+    }
+
+    public function testReverse()
+    {
+        $list = cons(1, cons(2, cons(3, null)));
+        $expected = toString(cons(3, cons(2, cons(1, null))));
+        $this->assertEquals($expected, toString(reverse($list)));
+    }
+
+    public function testMap()
+    {
+        $list = cons(1, cons(2, cons(3, null)));
+        $expected = toString(cons(3, cons(4, cons(5, null))));
+        $map = map(function ($x) {
+            return $x + 2;
+        }, $list);
+        $this->assertEquals($expected, toString($map));
+    }
+
+    public function testFilter()
+    {
+        $list = cons(2, cons(3, cons(4, null)));
+        $expected = toString(cons(2, cons(4, null)));
+        $filter = filter(function ($x) {
+            return $x % 2 == 0;
+        }, $list);
+
+        $this->assertEquals(2, length($filter));
+        $this->assertEquals($expected, toString($filter));
+    }
+
+    public function testReduce()
+    {
+        $list = cons(1, cons(2, cons(3, null)));
+        $expected = 6;
+        $map = reduce(function ($x, $acc) {
+            return $x + $acc;
+        }, $list, 0);
+        $this->assertEquals($expected, $map);
+    }
+}

tests/PairsTest.php

@@ -2,8 +2,6 @@
 
 namespace Pairs\tests;
 
-require_once 'Pairs.php';
-
 use function Pairs\cons;
 use function Pairs\car;
 use function Pairs\cdr;