From 8fb0f6791ef26445c5d9251ff5d6774c2e738195 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=92=D0=B8=D0=BA=D1=82=D0=BE=D1=80=20=D0=92=D0=BE=D0=BB?=
 =?UTF-8?q?=D0=BA=D0=BE=D0=B2?= <vv_volkov@mail.ru>
Date: Tue, 9 Aug 2022 16:58:08 +0300
Subject: [PATCH] feat: implement Lua script engine

---
 .phpunit.result.cache                     |   2 +-
 README.md                                 |  27 +++++-
 src/CompiledScript.php                    |   2 +-
 src/Engine/Juel/JuelCompiledScript.php    |   3 +-
 src/Engine/Lua/LuaCompiledScript.php      |  39 ++++++++
 src/Engine/Lua/LuaScriptEngine.php        |  69 ++++++++++++++
 src/Engine/Lua/LuaScriptEngineFactory.php | 107 ++++++++++++++++++++++
 src/ScriptEngineManager.php               |   6 +-
 tests/LuaEngineTest.php                   |  33 +++++++
 9 files changed, 281 insertions(+), 7 deletions(-)
 create mode 100644 src/Engine/Lua/LuaCompiledScript.php
 create mode 100644 src/Engine/Lua/LuaScriptEngine.php
 create mode 100644 src/Engine/Lua/LuaScriptEngineFactory.php
 create mode 100644 tests/LuaEngineTest.php

diff --git a/.phpunit.result.cache b/.phpunit.result.cache
index 7f518f4..8711632 100644
--- a/.phpunit.result.cache
+++ b/.phpunit.result.cache
@@ -1 +1 @@
-{"version":1,"defects":{"Tests\\JuelEngineTest::testEngine":4,"Tests\\JuelEngineTest::testEngineManager":5,"Tests\\JuelEngineTest::testEngineFactory":4,"Tests\\JuelEngineTest::testJuelEngineManager":4,"Tests\\ExpressionLanguageTest::testNumericMethods":4,"Tests\\ExpressionLanguageTest::testMethodInvocation":4,"Tests\\JuelEngineTest::testJuelEngineManagerWithFunction":4},"times":{"Tests\\JuelEngineTest::testEngine":0.003,"Tests\\JuelEngineTest::testEngineFactory":0.006,"Tests\\JuelEngineTest::testEngineManager":0.003,"Tests\\JuelEngineTest::testJuelEngineManager":0.001,"Tests\\ExpressionLanguageTest::testNumericVariables":0.006,"Tests\\ExpressionLanguageTest::testNumericMethods":0,"Tests\\ExpressionLanguageTest::testBooleanMethods":0,"Tests\\ExpressionLanguageTest::testMethodInvocation":0.001,"Tests\\ExpressionLanguageTest::testExpressionString":0,"Tests\\ExpressionLanguageTest::testIsDeferred":0,"Tests\\ExpressionLanguageTest::testGetExpectedType":0,"Tests\\ExpressionLanguageTest::testGetType":0,"Tests\\JuelEngineTest::testJuelEngineManagerWithVariable":0.001,"Tests\\JuelEngineTest::testJuelEngineManagerWithFunction":0.001}}
\ No newline at end of file
+{"version":1,"defects":{"Tests\\JuelEngineTest::testEngine":4,"Tests\\JuelEngineTest::testEngineManager":5,"Tests\\JuelEngineTest::testEngineFactory":4,"Tests\\JuelEngineTest::testJuelEngineManager":4,"Tests\\ExpressionLanguageTest::testNumericMethods":4,"Tests\\ExpressionLanguageTest::testMethodInvocation":4,"Tests\\JuelEngineTest::testJuelEngineManagerWithFunction":4,"Tests\\LuaEngineTest::testLuaScript":5},"times":{"Tests\\JuelEngineTest::testEngine":0.003,"Tests\\JuelEngineTest::testEngineFactory":0.006,"Tests\\JuelEngineTest::testEngineManager":0.003,"Tests\\JuelEngineTest::testJuelEngineManager":0.001,"Tests\\ExpressionLanguageTest::testNumericVariables":0.006,"Tests\\ExpressionLanguageTest::testNumericMethods":0,"Tests\\ExpressionLanguageTest::testBooleanMethods":0,"Tests\\ExpressionLanguageTest::testMethodInvocation":0.001,"Tests\\ExpressionLanguageTest::testExpressionString":0,"Tests\\ExpressionLanguageTest::testIsDeferred":0,"Tests\\ExpressionLanguageTest::testGetExpectedType":0,"Tests\\ExpressionLanguageTest::testGetType":0,"Tests\\JuelEngineTest::testJuelEngineManagerWithVariable":0.001,"Tests\\JuelEngineTest::testJuelEngineManagerWithFunction":0.001,"Tests\\LuaEngineTest::testLuaScript":0.001}}
\ No newline at end of file
diff --git a/README.md b/README.md
index 35fe5a6..5b7b82c 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ Install library, using Composer:
 composer require bingo-soft/script
 ```
 
-# Example 1
+# Example 1 (using Juel engine)
 
 ```
 $manager = new ScriptEngineManager();
@@ -23,7 +23,7 @@ $engine = $manager->getEngineByName("juel");
 echo $engine->eval('${1 + 2}'); //prints 3
 ```
 
-# Example 2
+# Example 2 (using Juel engine)
 
 ```
 $manager = new ScriptEngineManager();
@@ -48,8 +48,31 @@ echo $engine->eval('${simple.propFloat + 2}'); //prints 3.23
 echo $engine->eval('${simple.bar() + simple.foo()}'); //prints 34
 ```
 
+# Example 3. Calculate factorial using Lua module
+
+```
+$manager = new ScriptEngineManager();
+$engine = $manager->getEngineByName("lua");
+$engine->put('a', 5);
+
+echo  $engine->eval(<<<CODE
+                factorial = function ( n )
+                    if n == 1 then return 1
+                    else return n * factorial( n - 1 )
+                    end
+                end
+                return factorial(a)
+                CODE
+            ); //prints 120
+
+```
+
 # Running tests
 
 ```
 ./vendor/bin/phpunit ./tests
 ```
+
+# Dependencies
+
+Lua script engine depends on PHP [Lua](https://pecl.php.net/package/lua) module. The library is tested against 2.0.7 version.
\ No newline at end of file
diff --git a/src/CompiledScript.php b/src/CompiledScript.php
index d93f6cb..8754af6 100644
--- a/src/CompiledScript.php
+++ b/src/CompiledScript.php
@@ -35,7 +35,7 @@ abstract public function evalContext(ScriptContextInterface $context);
      *
      * @throws ScriptException if an error occurs.
      */
-    public function eval(?BindingsInterface $bindings = null)
+    public function eval(BindingsInterface $bindings = null)
     {
         $ctxt = $this->getEngine()->getContext();
 
diff --git a/src/Engine/Juel/JuelCompiledScript.php b/src/Engine/Juel/JuelCompiledScript.php
index 04b1ef4..0505b76 100644
--- a/src/Engine/Juel/JuelCompiledScript.php
+++ b/src/Engine/Juel/JuelCompiledScript.php
@@ -22,11 +22,10 @@ public function __construct(JuelScriptEngine $engine, ValueExpression $valueExpr
 
     public function getEngine(): ScriptEngineInterface
     {
-        // Return outer class instance
         return $engine;
     }
 
-    public function eval(?BindingsInterface $ctx = null)
+    public function eval(BindingsInterface $ctx = null)
     {
         return $this->scope->evaluateExpression($this->valueExpression, $ctx);
     }
diff --git a/src/Engine/Lua/LuaCompiledScript.php b/src/Engine/Lua/LuaCompiledScript.php
new file mode 100644
index 0000000..b12f51b
--- /dev/null
+++ b/src/Engine/Lua/LuaCompiledScript.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Script\Engine\Lua;
+
+use Script\{
+    CompiledScript,
+    ScriptContextInterface,
+    ScriptEngineInterface
+};
+
+class LuaCompiledScript extends CompiledScript
+{
+    private $script;
+    private $engine;
+
+    public function __construct(LuaScriptEngine $engine, string $script)
+    {
+        $this->engine = $engine;
+        $this->script = $script;        
+    }
+
+    public function getEngine(): ScriptEngineInterface
+    {
+        return $engine;
+    }
+
+    public function evalContext(ScriptContextInterface $context)
+    {
+        $lua = new \Lua();
+
+        $bindings = $context->getBindings(ScriptContextInterface::ENGINE_SCOPE);
+        $entries = $bindings->entrySet();
+        foreach ($entries as $key => $value) {
+            $lua->assign($key, $value);
+        }
+
+        return $lua->eval($this->script);
+    }
+}
diff --git a/src/Engine/Lua/LuaScriptEngine.php b/src/Engine/Lua/LuaScriptEngine.php
new file mode 100644
index 0000000..fb3d260
--- /dev/null
+++ b/src/Engine/Lua/LuaScriptEngine.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Script\Engine\Lua;
+
+use El\{
+    ArrayELResolver,
+    ObjectELResolver,
+    CompositeELResolver,
+    ELContext,
+    ELException,
+    ELResolver,
+    ExpressionFactory,
+    FunctionMapper,
+    ListELResolver,
+    MapELResolver,
+    ValueExpression,
+    VariableMapper
+};
+use Script\{
+    AbstractScriptEngine,
+    BindingsInterface,
+    CompilableInterface,
+    CompiledScript,
+    ScriptContextInterface,
+    ScriptEngineInterface,
+    ScriptEngineFactoryInterface,
+    ScriptException,
+    SimpleBindings,
+    SimpleScriptContext
+};
+
+class LuaScriptEngine extends AbstractScriptEngine implements ScriptEngineInterface, CompilableInterface
+{
+    private $scriptEngineFactory;
+
+    public function __construct(ScriptEngineFactoryInterface $scriptEngineFactory = null)
+    {
+        parent::__construct();
+        $this->scriptEngineFactory = $scriptEngineFactory ?? new LuaScriptEngineFactory();        
+    }
+
+    public function getFactory(): ScriptEngineFactoryInterface
+    {
+		return $this->scriptEngineFactory;
+    }
+    
+    public function createBindings(): BindingsInterface
+    {
+        return new SimpleBindings();
+    }
+
+    public function eval(string $script, $scriptContextOrBindings = null)
+    {
+        if ($scriptContextOrBindings instanceof BindingsInterface) {
+            $scriptContext = $this->getScriptContext($scriptContextOrBindings);
+        } elseif ($scriptContextOrBindings instanceof ScriptContextInterface) {
+            $scriptContext = $scriptContext;
+        } else {
+            $scriptContext = $this->context;
+        }
+        //$expr = $this->parse($script, $scriptContext);
+        return $this->compile($script)->evalContext($scriptContext);
+    }
+
+    public function compile(string $script): CompiledScript
+    {
+        return new LuaCompiledScript($this, $script);
+    }
+}
diff --git a/src/Engine/Lua/LuaScriptEngineFactory.php b/src/Engine/Lua/LuaScriptEngineFactory.php
new file mode 100644
index 0000000..7451843
--- /dev/null
+++ b/src/Engine/Lua/LuaScriptEngineFactory.php
@@ -0,0 +1,107 @@
+<?php
+
+namespace Script\Engine\Lua;
+
+use Script\{
+    ScriptEngineInterface,
+    ScriptEngineFactoryInterface
+};
+
+class LuaScriptEngineFactory implements ScriptEngineFactoryInterface
+{    
+    public const NAMES = [ "lua" ];
+    private const EXTENSIONS = [ "lua", ".lua" ];
+    private const MIMETYPES = ["text/lua", "application/lua"];
+    
+    public function getEngineName(): string
+    {
+        return "lua";
+    }
+    
+    public function getEngineVersion(): string
+    {
+        return "1.0";
+    }
+    
+    public function getExtensions(): array
+    {
+        return self::EXTENSIONS;
+    }
+    
+    public function getMimeTypes(): array
+    {
+        return self::MIMETYPES;
+    }
+    
+    public function getNames(): array
+    {
+        return self::NAMES;
+    }
+    
+    public function getLanguageName(): string
+    {
+        return "1.0 Lua";
+    }
+    
+    public function getLanguageVersion(): string
+    {
+        return "1.0";
+    }
+    
+    public function getMethodCallSyntax(string $obj, string $m, ...$args): string
+    {
+        $sb = "";
+        $sb .= $obj . ":" . $m . "(";
+        $len = count($args);
+        for ($i = 0; $i < $len; $i += 1) {
+            if ($i > 0) {
+                $sb .= ',';
+            }
+            $sb .= $args[$i];
+        }
+        $sb .= ")";
+        return $sb;
+    }
+    
+    public function getOutputStatement(string $toDisplay): string
+    {
+        return "print(" . $toDisplay . ")";
+    }
+
+    public function getParameter(string $key)
+    {
+        if ($key == ScriptEngineInterface::NAME) {
+            return $this->getLanguageName();
+        } elseif ($key == ScriptEngineInterface::ENGINE) {
+            return $this->getEngineName();
+        } elseif ($key == ScriptEngineInterface::ENGINE_VERSION) {
+            return $this->getEngineVersion();
+        } elseif ($key == ScriptEngineInterface::LANGUAGE) {
+            return $this->getLanguageName();
+        } elseif ($key == ScriptEngineInterface::LANGUAGE_VERSION) {
+            return $this->getLanguageVersion();
+        } elseif ($key == "THREADING") {
+            return "MULTITHREADED";
+        } else {
+            return null;
+        }
+    }
+    
+    public function getProgram(...$statements): string
+    {
+        $sb = "";
+        $len = count($statements);
+        for ($i = 0; $i < $len; $i += 1) {
+            if ($i > 0) {
+                $sb .= '\n';
+            }
+            $sb .= $statements[$i];
+        }
+        return $sb;
+    }
+    
+    public function getScriptEngine(): ScriptEngineInterface
+    {
+        return new LuaScriptEngine();
+    }
+}
\ No newline at end of file
diff --git a/src/ScriptEngineManager.php b/src/ScriptEngineManager.php
index 0406f4d..4535706 100644
--- a/src/ScriptEngineManager.php
+++ b/src/ScriptEngineManager.php
@@ -3,6 +3,7 @@
 namespace Script;
 
 use Script\Engine\Juel\JuelScriptEngineFactory;
+use Script\Engine\Lua\LuaScriptEngineFactory;
 
 class ScriptEngineManager
 {
@@ -42,7 +43,10 @@ private function addSpi(): void
     {
         $factory = new JuelScriptEngineFactory();
         $this->engineSpis[] = $factory;
-        //register
+        $this->registerEngineName($factory->getEngineName(), $factory);
+
+        $factory = new LuaScriptEngineFactory();
+        $this->engineSpis[] = $factory;
         $this->registerEngineName($factory->getEngineName(), $factory);
     }
 
diff --git a/tests/LuaEngineTest.php b/tests/LuaEngineTest.php
new file mode 100644
index 0000000..3fcf534
--- /dev/null
+++ b/tests/LuaEngineTest.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Tests;
+
+use PHPUnit\Framework\TestCase;
+use Script\ScriptEngineManager;
+use Script\Engine\Lua\LuaScriptEngine;
+
+class LuaEngineTest extends TestCase
+{
+    public function testLuaScript(): void
+    {
+        if (class_exists(\Lua::class)) {
+            $manager = new ScriptEngineManager();
+            $engine = $manager->getEngineByName("lua");
+            $engine->put('a', 5);
+            $this->assertEquals(
+                120,
+                $engine->eval(<<<CODE
+                    factorial = function ( n )
+                        if n == 1 then return 1
+                        else return n * factorial( n - 1 )
+                        end
+                    end
+                    return factorial(a)
+                    CODE
+                )
+            );
+        } else {
+            $this->assertTrue(true);
+        }
+    }
+}