chore: add message example

Signed-off-by: azjezz <azjezz@protonmail.com>

Author: azjezz

benchmarks/EvaluationBenchmark.php

@@ -10,18 +10,14 @@
 use PhpBench\Benchmark\Metadata\Annotations\Iterations;
 use PhpBench\Benchmark\Metadata\Annotations\Revs;
 use PhpBench\Benchmark\Metadata\Annotations\Warmup;
+use Psl\Vec;
 use Symfony\Component\Cache\Adapter\NullAdapter;
 use Symfony\Component\ExpressionLanguage\ExpressionFunction;
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage as SymfonyExpressionLanguage;
 use Symfony\Component\ExpressionLanguage\ParsedExpression as SymfonyExpression;
 
-use function array_keys;
-use function assert;
 use function extract;
 
-/**
- * @mago-expect lint:no-boolean-literal-comparison
- */
 final class EvaluationBenchmark
 {
     private const string CEL_EXPRESSION = <<<'CEL'
@@ -154,7 +150,7 @@ public function benchCachedSymfonyExpression(): void
         $symfony->addFunction(ExpressionFunction::fromPhp('mb_strtoupper', 'toUpper'));
 
         if ($expression === null) {
-            $expression = $symfony->parse(self::SEL_EXPRESSION, array_keys(self::ENVIRONMENT));
+            $expression = $symfony->parse(self::SEL_EXPRESSION, Vec\keys(self::ENVIRONMENT));
         }
 
         $_ = $symfony->evaluate($expression, self::ENVIRONMENT);

examples/lexer.php

@@ -2,6 +2,8 @@
 
 declare(strict_types=1);
 
+namespace Cel\Examples;
+
 use Cel\Input\Input;
 use Cel\Lexer\Lexer;
 use Cel\Token\Token;

examples/message.php

@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cel\Examples;
+
+use Cel;
+use Cel\Runtime\Exception\InvalidMessageFieldsException;
+use Cel\Runtime\Value;
+use Override;
+use Psl;
+use Psl\Json;
+use Psl\Type;
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+final readonly class RequestMessage implements Cel\Runtime\Message\MessageInterface
+{
+    public function __construct(
+        public int $id,
+        public string $name,
+        public null|string $email,
+    ) {}
+
+    /**
+     * @inheritDoc
+     */
+    #[Override]
+    public function toCelValue(): Value\Value
+    {
+        return new Value\MessageValue($this, [
+            'id' => Value\Value::from($this->id),
+            'name' => Value\Value::from($this->name),
+            'email' => Value\Value::from($this->email),
+        ]);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    #[Override]
+    public static function fromCelFields(array $fields): static
+    {
+        try {
+            $fields = Type\shape([
+                'id' => Type\instance_of(Value\IntegerValue::class),
+                'name' => Type\instance_of(Value\StringValue::class),
+                'email' => Type\optional(Type\union(
+                    Type\instance_of(Value\NullValue::class),
+                    Type\instance_of(Value\StringValue::class),
+                )),
+            ])->assert($fields);
+
+            $id = $fields['id']->getNativeValue();
+            $name = $fields['name']->getNativeValue();
+            $email = isset($fields['email']) ? $fields['email']->getNativeValue() : null;
+
+            return new self(
+                id: $id,
+                name: $name,
+                email: $email,
+            );
+        } catch (Type\Exception\AssertException $e) {
+            throw new InvalidMessageFieldsException('Unable to create RequestMessage from CEL fields.', previous: $e);
+        }
+    }
+}
+
+$configuration = new Cel\Runtime\Configuration(allowedMessageClasses: [
+    RequestMessage::class,
+]);
+
+$message = Cel\evaluate('Cel.Examples.RequestMessage { id: 1234, name: "John Doe" }', configuration: $configuration);
+Psl\invariant($message->getNativeValue() instanceof RequestMessage, 'Expected a RequestMessage instance.');
+
+$message = Cel\evaluate(
+    'Cel.Examples.RequestMessage { id: 1234, name: "John Doe", email: null }',
+    configuration: $configuration,
+);
+Psl\invariant($message->getNativeValue() instanceof RequestMessage, 'Expected a RequestMessage instance.');
+
+$message = Cel\evaluate(
+    'Cel.Examples.RequestMessage { id: 1234, name: "John Doe", email: "john.doe@example.com" }',
+    configuration: $configuration,
+);
+Psl\invariant($message->getNativeValue() instanceof RequestMessage, 'Expected a RequestMessage instance.');
+
+$result = Cel\evaluate(
+    'has(message.email) ? message.email : null',
+    variables: ['message' => $message],
+    configuration: $configuration,
+);
+Psl\invariant($result->getNativeValue() === 'john.doe@example.com', 'Expected email to exist');
+
+Psl\IO\write_line('RequestMessage created successfully: %s', Json\encode($message->getNativeValue(), true));

examples/simple.php

@@ -2,8 +2,13 @@
 
 declare(strict_types=1);
 
+namespace Cel\Examples;
+
+use Cel;
 use Psl\IO;
 
+use function var_export;
+
 require_once __DIR__ . '/../vendor/autoload.php';
 
 const EXPRESSION = <<<CEL