Add CodeExporter, fixes #30

README.md

@@ -505,6 +505,28 @@ try {
 }
 ```
 
+## Literal code expressions
+
+```php
+use Brick\VarExporter\VarExporter;
+use Brick\Code;
+
+echo VarExporter::export([
+  'literal_expression' => Code::create("$app_root", ". '/../private'");
+], VarExporter::ALLOW_CODE);
+```
+
+This code will output:
+
+```php
+[
+    'literal_expression' => $app_root
+        . '/../private',
+]
+```
+
+Also, you can implement CodeInterface in your custom code.
+
 ## Limitations
 
 - Exporting internal classes other than `stdClass` and `Closure`, and classes implementing `__set_state()` (most notably DateTime classes) is currently not supported. `VarExporter` will throw an `ExportException` if it finds one.

src/Code.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+namespace Brick\VarExporter;
+
+final class Code implements CodeInterface {
+
+    /**
+     * @var string[]
+     */
+    private array $lines;
+
+    /**
+     * @param string[] $lines
+     */
+    private function __construct(array $lines) {
+        $this->lines = $lines;
+    }
+
+    public static function create(string ...$lines): self {
+        return new self($lines);
+    }
+
+    public function toLines(): array
+    {
+        return $this->lines;
+    }
+
+}

src/CodeInterface.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+namespace Brick\VarExporter;
+
+interface CodeInterface {
+
+    /**
+     * @return string[]
+     */
+    public function toLines(): array;
+
+}

src/Internal/GenericExporter.php

@@ -74,6 +74,13 @@ final class GenericExporter
      */
     public $trailingCommaInArray;
 
+    /**
+     * @psalm-readonly
+     *
+     * @var bool
+     */
+    public $allowCode;
+
     /**
      * @psalm-readonly
      *
@@ -83,6 +90,7 @@ final class GenericExporter
 
     public function __construct(int $options, int $indentLevel = 0)
     {
+        $this->objectExporters[] = new ObjectExporter\CodeExporter($this);
         $this->objectExporters[] = new ObjectExporter\StdClassExporter($this);
 
         if (! ($options & VarExporter::NO_CLOSURES)) {
@@ -113,6 +121,7 @@ public function __construct(int $options, int $indentLevel = 0)
         $this->inlineScalarList         = (bool) ($options & VarExporter::INLINE_SCALAR_LIST);
         $this->closureSnapshotUses      = (bool) ($options & VarExporter::CLOSURE_SNAPSHOT_USES);
         $this->trailingCommaInArray     = (bool) ($options & VarExporter::TRAILING_COMMA_IN_ARRAY);
+        $this->allowCode                = (bool) ($options & VarExporter::ALLOW_CODE);
 
         $this->indentLevel = $indentLevel;
     }

src/Internal/ObjectExporter/CodeExporter.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Brick\VarExporter\Internal\ObjectExporter;
+
+use Brick\VarExporter\Internal\ObjectExporter;
+use Brick\VarExporter\CodeInterface;
+
+/**
+ * Handles instances of LiteralInterface.
+ *
+ * @internal This class is for internal use, and not part of the public API. It may change at any time without warning.
+ */
+final class CodeExporter extends ObjectExporter
+{
+
+    public function supports(\ReflectionObject $reflectionObject): bool
+    {
+        return $this->exporter->allowCode
+            && $reflectionObject->implementsInterface(CodeInterface::class);
+    }
+
+    public function export(object $object, \ReflectionObject $reflectionObject, array $path, array $parentIds): array
+    {
+        assert($object instanceof CodeInterface);
+        return $object->toLines();
+    }
+
+}

src/VarExporter.php

@@ -74,6 +74,11 @@ final class VarExporter
      */
     public const INLINE_ARRAY = 1 << 11;
 
+    /**
+     * Any value implementing CodeInterface will print a literal expression.
+     */
+    public const ALLOW_CODE = 1 << 12;
+
     /**
      * @param mixed $var       The variable to export.
      * @param int   $options   A bitmask of options. Possible values are `VarExporter::*` constants.