Merge pull request #429 from a1812/interpreter

Add pattern Interpreter

Behavioral/Interpreter/AbstractExp.php

@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter;
+
+abstract class AbstractExp
+{
+    abstract public function interpret(Context $context): bool;
+}

Behavioral/Interpreter/AndExp.php

@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter;
+
+/**
+ * This NoTerminalExpression
+ */
+class AndExp extends AbstractExp
+{
+    public function __construct(private AbstractExp $first, private AbstractExp $second)
+    {
+    }
+
+    public function interpret(Context $context): bool
+    {
+        return $this->first->interpret($context) && $this->second->interpret($context);
+    }
+}

Behavioral/Interpreter/Context.php

@@ -0,0 +1,24 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter;
+
+use Exception;
+
+class Context
+{
+    private array $poolVariable;
+
+    public function lookUp(string $name): bool
+    {
+        if (!key_exists($name, $this->poolVariable)) {
+            throw new Exception("no exist variable: $name");
+        }
+
+        return $this->poolVariable[$name];
+    }
+
+    public function assign(VariableExp $variable, bool $val)
+    {
+        $this->poolVariable[$variable->getName()] = $val;
+    }
+}

Behavioral/Interpreter/OrExp.php

@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter;
+
+/**
+ * This NoTerminalExpression
+ */
+class OrExp extends AbstractExp
+{
+    public function __construct(private AbstractExp $first, private AbstractExp $second)
+    {
+    }
+
+    public function interpret(Context $context): bool
+    {
+        return $this->first->interpret($context) || $this->second->interpret($context);
+    }
+}

Behavioral/Interpreter/README.rst

@@ -0,0 +1,71 @@
+`Interpreter`__
+============
+
+Purpose
+-------
+
+For a given language, it defines the representation of its grammar as
+"No Terminal Expression" and "Terminal Expression",
+as well as an interpreter for the sentences of that language.
+
+Examples
+--------
+
+-  An example of a binary logic interpreter, each definition is defined by its own class
+
+UML Diagram
+-----------
+
+.. image:: uml/uml.png
+   :alt: Alt Interpreter UML Diagram
+   :align: center
+
+Code
+----
+
+You can also find this code on `GitHub`_
+
+AbstractExp.php
+
+.. literalinclude:: AbstractExp.php
+   :language: php
+   :linenos:
+
+Context.php
+
+.. literalinclude:: Context.php
+   :language: php
+   :linenos:
+
+
+VariableExp.php
+
+.. literalinclude:: VariableExp.php
+   :language: php
+   :linenos:
+
+
+AndExp.php
+
+.. literalinclude:: AndExp.php
+   :language: php
+   :linenos:
+
+
+OrExp.php
+
+.. literalinclude:: OrExp.php
+   :language: php
+   :linenos:
+
+Test
+----
+
+Tests/InterpreterTest.php
+
+.. literalinclude:: Tests/InterpreterTest.php
+   :language: php
+   :linenos:
+
+.. _`GitHub`: https://github.com/domnikl/DesignPatternsPHP/tree/main/Behavioral/Interpreter
+.. __: https://en.wikipedia.org/wiki/Interpreter_pattern

Behavioral/Interpreter/Tests/InterpreterTest.php

@@ -0,0 +1,63 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter\Tests;
+
+use DesignPatterns\Behavioral\Interpreter\AndExp;
+use DesignPatterns\Behavioral\Interpreter\Context;
+use DesignPatterns\Behavioral\Interpreter\OrExp;
+use DesignPatterns\Behavioral\Interpreter\VariableExp;
+use PHPUnit\Framework\TestCase;
+
+class InterpreterTest extends TestCase
+{
+    private Context $context;
+    private VariableExp $a;
+    private VariableExp $b;
+    private VariableExp $c;
+
+    public function setUp(): void
+    {
+        $this->context = new Context();
+        $this->a = new VariableExp('A');
+        $this->b = new VariableExp('B');
+        $this->c = new VariableExp('C');
+    }
+
+    public function testOr()
+    {
+        $this->context->assign($this->a, false);
+        $this->context->assign($this->b, false);
+        $this->context->assign($this->c, true);
+
+        // A ∨ B
+        $exp1 = new OrExp($this->a, $this->b);
+        $result1 = $exp1->interpret($this->context);
+
+        $this->assertFalse($result1, 'A ∨ B must false');
+
+        // $exp1 ∨ C
+        $exp2 = new OrExp($exp1, $this->c);
+        $result2 = $exp2->interpret($this->context);
+
+        $this->assertTrue($result2, '(A ∨ B) ∨ C must true');
+    }
+
+    public function testAnd()
+    {
+        $this->context->assign($this->a, true);
+        $this->context->assign($this->b, true);
+        $this->context->assign($this->c, false);
+
+        // A ∧ B
+        $exp1 = new AndExp($this->a, $this->b);
+        $result1 = $exp1->interpret($this->context);
+
+        $this->assertTrue($result1, 'A ∧ B must true');
+
+        // $exp1 ∧ C
+        $exp2 = new AndExp($exp1, $this->c);
+        $result2 = $exp2->interpret($this->context);
+
+        $this->assertFalse($result2, '(A ∧ B) ∧ C must false');
+    }
+}

Behavioral/Interpreter/VariableExp.php

@@ -0,0 +1,23 @@
+<?php declare(strict_types=1);
+
+namespace DesignPatterns\Behavioral\Interpreter;
+
+/**
+ * This TerminalExpression
+ */
+class VariableExp extends AbstractExp
+{
+    public function __construct(private string $name)
+    {
+    }
+
+    public function interpret(Context $context): bool
+    {
+        return $context->lookUp($this->name);
+    }
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+}

Behavioral/README.md

@@ -7,6 +7,7 @@ communication.
 
 * [ChainOfResponsibilities](ChainOfResponsibilities) [:notebook:](http://en.wikipedia.org/wiki/Chain_of_responsibility_pattern)
 * [Command](Command) [:notebook:](http://en.wikipedia.org/wiki/Command_pattern)
+* [Interpreter](Interpreter) [:notebook:](https://en.wikipedia.org/wiki/Interpreter_pattern)
 * [Iterator](Iterator) [:notebook:](http://en.wikipedia.org/wiki/Iterator_pattern)
 * [Mediator](Mediator) [:notebook:](http://en.wikipedia.org/wiki/Mediator_pattern)
 * [Memento](Memento) [:notebook:](http://en.wikipedia.org/wiki/Memento_pattern)

Behavioral/README.rst

@@ -11,6 +11,7 @@ carrying out this communication.
 
    ChainOfResponsibilities/README
    Command/README
+   Interpreter/README
    Iterator/README
    Mediator/README
    Memento/README

README.md

@@ -79,6 +79,7 @@ The patterns can be structured in roughly three different categories. Please cli
 
 * [ChainOfResponsibilities](Behavioral/ChainOfResponsibilities) [:notebook:](http://en.wikipedia.org/wiki/Chain_of_responsibility_pattern)
 * [Command](Behavioral/Command) [:notebook:](http://en.wikipedia.org/wiki/Command_pattern)
+* [Interpreter](Behavioral/Interpreter) [:notebook:](https://en.wikipedia.org/wiki/Interpreter_pattern)  
 * [Iterator](Behavioral/Iterator) [:notebook:](http://en.wikipedia.org/wiki/Iterator_pattern)
 * [Mediator](Behavioral/Mediator) [:notebook:](http://en.wikipedia.org/wiki/Mediator_pattern)
 * [Memento](Behavioral/Memento) [:notebook:](http://en.wikipedia.org/wiki/Memento_pattern)