Merge pull request #22 from worksolutions/bool-expression

Bool Expression functional

Author: sokolovsky

src/WS/Utils/Collections/Functions/Expression/BoolExpression.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * @author Anton Lytkin <a.lytkin@worksolutions.ru>
+ */
+
+namespace WS\Utils\Collections\Functions\Expression;
+
+use WS\Utils\Collections\Functions\Expression\Operator\AbstractOperator;
+use WS\Utils\Collections\Functions\Expression\Operator\AndOperator;
+use WS\Utils\Collections\Functions\Expression\Operator\OrOperator;
+
+class BoolExpression
+{
+
+    /** @var AbstractOperator[] */
+    private $operators = [];
+
+    public function __construct(callable $checker)
+    {
+        $this->operators[] = new AndOperator($checker);
+    }
+
+    public static function with(callable $checker): self
+    {
+        return new self($checker);
+    }
+
+    public function __invoke($item): bool
+    {
+        $operand = null;
+        foreach ($this->operators as $operator) {
+            if ($operand === null) {
+                if (!$operand = $operator->getChecker()($item)) {
+                    return false;
+                }
+                continue;
+            }
+            if (!$operand = $operator($operand, $item)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public function and(callable $checker): self
+    {
+        $this->operators[] = new AndOperator($checker);
+        return $this;
+    }
+
+    public function or(callable $checker): self
+    {
+        $this->operators[] = new OrOperator($checker);
+        return $this;
+    }
+
+}

src/WS/Utils/Collections/Functions/Expression/Operator/AbstractOperator.php

@@ -0,0 +1,24 @@
+<?php
+/**
+ * @author Anton Lytkin <a.lytkin@worksolutions.ru>
+ */
+
+namespace WS\Utils\Collections\Functions\Expression\Operator;
+
+abstract class AbstractOperator
+{
+    protected $checker;
+
+    public function __construct(callable $checker)
+    {
+        $this->checker = $checker;
+    }
+
+    public function getChecker(): callable
+    {
+        return $this->checker;
+    }
+
+    abstract public function __invoke(bool $operand, $item): bool;
+
+}

src/WS/Utils/Collections/Functions/Expression/Operator/AndOperator.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * @author Anton Lytkin <a.lytkin@worksolutions.ru>
+ */
+
+namespace WS\Utils\Collections\Functions\Expression\Operator;
+
+class AndOperator extends AbstractOperator
+{
+
+    public function __invoke(bool $operand, $item): bool
+    {
+        if (!$operand) {
+            return false;
+        }
+        $checker = $this->checker;
+        return $checker($item);
+    }
+
+}

src/WS/Utils/Collections/Functions/Expression/Operator/OrOperator.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * @author Anton Lytkin <a.lytkin@worksolutions.ru>
+ */
+
+namespace WS\Utils\Collections\Functions\Expression\Operator;
+
+class OrOperator extends AbstractOperator
+{
+
+    public function __invoke(bool $operand, $item): bool
+    {
+        if ($operand) {
+            return true;
+        }
+        $checker = $this->checker;
+        return $checker($item);
+    }
+
+}

tests/WS/Utils/Collections/Functions/Expression/BoolExpressionTest.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * @author Anton Lytkin <a.lytkin@worksolutions.ru>
+ */
+
+namespace WS\Utils\Collections\Functions\Expression;
+
+use PHPUnit\Framework\TestCase;
+use WS\Utils\Collections\CollectionFactory;
+
+class BoolExpressionTest extends TestCase
+{
+
+    public function cases()
+    {
+        return [
+            [
+                [1, 2, 3],
+                BoolExpression::with(function ($element) {
+                    return is_int($element);
+                })
+                    ->or(function ($element) {
+                        return $element === 77;
+                    })
+                    ->and(function ($element) {
+                        return in_array($element, [1, 3]);
+                    }),
+                [1, 3],
+            ],
+        ];
+    }
+
+    /**
+     * @test
+     * @dataProvider cases
+     * @param array $sequence
+     * @param BoolExpression $expression
+     * @param array $expected
+     */
+    public function filterByExpression(array $sequence, BoolExpression $expression, array $expected)
+    {
+
+        $result = CollectionFactory::from($sequence)
+            ->stream()
+            ->filter($expression)
+            ->getCollection()
+            ->toArray();
+
+        self::assertEquals($expected, $result);
+    }
+
+}