Added README

Author: gplanchat

README.md

@@ -0,0 +1,167 @@
+FastMap Config, a fluent interface for configuring your mappings
+===
+
+Example 1: configure mapping for an array
+---
+
+```php
+<?php
+
+use Kiboko\Component\ETL\Config\ArrayBuilder;
+use Kiboko\Component\ETL\FastMap\Compiler;
+use Kiboko\Component\ETL\FastMap\PropertyAccess\EmptyPropertyPath;
+use Symfony\Component\ExpressionLanguage\ExpressionFunction;
+
+$input = [
+    'customer' => [
+        'firstName' => 'John',
+        'lastName' => 'Doe',
+        'email' => '[email protected]',
+    ],
+    'items' => [
+        [
+            'sku' => '123456',
+            'price' => [
+                'value' => 123.45,
+                'currency' => 'EUR',
+            ],
+            'weight' => [
+                'value' => 123.45,
+                'KILOGRAM',
+            ],
+        ],
+        [
+            'sku' => '234567',
+            'price' => [
+                'value' => 23.45,
+                'currency' => 'EUR',
+            ],
+            'weight' => [
+                'value' => 13.45,
+                'KILOGRAM',
+            ],
+        ],
+    ],
+    'shippings' => [
+        [
+            'sku' => '123456',
+            'price' => [
+                'value' => 123.45,
+                'currency' => 'EUR',
+            ],
+        ],
+        [
+            'sku' => '234567',
+            'price' => [
+                'value' => 23.45,
+                'currency' => 'EUR',
+            ],
+        ],
+    ],
+];
+
+$compiler = new Compiler\Compiler(new Compiler\Strategy\Spaghetti());
+
+$interpreter = new Symfony\Component\ExpressionLanguage\ExpressionLanguage();
+$interpreter->addFunction(ExpressionFunction::fromPhp('array_merge', 'merge'));
+$interpreter->addFunction(new ExpressionFunction(
+    'price',
+    function (array $context, float $value, string $currency) {
+        return sprintf('\sprintf("%%s %%s", \number_format(%s, 2), "%s")', $value, addslashes($currency));
+    },
+    function (array $context, float $value, string $currency) {
+        return sprintf('%s %s', number_format($value, 2), $currency);
+    }
+));
+
+$mapper = (new ArrayBuilder(null, $interpreter))
+    ->children()
+        ->constant('[type]', 'ORDER')
+        ->copy('[customer][first_name]', '[customer][firstName]')
+        ->copy('[customer][last_name]', '[customer][lastName]')
+        ->list('[products]', 'merge( input["items"], input["shippings"] )')
+            ->children()
+                ->copy('[sku]', '[sku]')
+                ->expression('[price]', 'price( input["price"]["value"], input["price"]["currency"] )')
+            ->end()
+        ->end()
+    ->end()
+    ->getMapper();
+
+$compiler->compile(
+    Compiler\StandardCompilationContext::build(new EmptyPropertyPath(), __DIR__, 'Foo\\ArraySpaghettiMapper'),
+    $mapper
+);
+
+var_dump($mapper($input, [], new EmptyPropertyPath()));
+```
+
+Example 2: configure mapping for an object
+---
+
+```php
+<?php
+
+use Kiboko\Component\ETL\Config\CompositeBuilder;use Kiboko\Component\ETL\Config\ObjectBuilder;
+use Kiboko\Component\ETL\FastMap\Compiler;
+use Kiboko\Component\ETL\FastMap\PropertyAccess\EmptyPropertyPath;
+use Symfony\Component\ExpressionLanguage\ExpressionFunction;
+
+class Order
+{
+    public ?Customer $customer = null;
+    public iterable $products;
+
+    public function __construct()
+    {
+        $this->products = [];
+    }
+}
+class Customer
+{
+    public string $firstName;
+    public string $lastName;
+}
+class Product
+{
+    public string $sku;
+    public ?Price $price = null;
+}
+class Price
+{
+    public float $amount;
+    public string $currency;
+}
+
+$mapper = (new ObjectBuilder(Order::class, null, $interpreter))
+    ->children()
+        ->object('customer', 'input["customer"]', Customer::class)
+            ->children()
+                ->merge(
+                    (new CompositeBuilder(null, $interpreter))
+                        ->copy('firstName', '[firstName]')
+                        ->copy('lastName', '[lastName]')
+                )
+            ->end()
+        ->end()
+        ->collection('products', 'merge( input["items"], input["shippings"] )', Product::class)
+            ->children()
+                ->copy('sku', '[sku]')
+                ->object('price', 'input["price"]', Price::class)
+                    ->children()
+                        ->expression('amount', 'input["value"]')
+                        ->expression('currency', 'input["currency"]')
+                    ->end()
+                ->end()
+            ->end()
+        ->end()
+    ->end()
+    ->getMapper();
+
+var_dump($mapper($input, [], new EmptyPropertyPath()));
+
+$compiler->compile(
+    Compiler\StandardCompilationContext::build(new EmptyPropertyPath(), __DIR__, 'Foo\\ObjectSpaghettiMapper'),
+    $mapper
+);
+```