Optimize compiled string definitions

 - run preg_replace_callback already during compilation

Author: falkenhawk

src/CompiledContainer.php

@@ -16,6 +16,7 @@
 use Invoker\ParameterResolver\DefaultValueResolver;
 use Invoker\ParameterResolver\NumericArrayResolver;
 use Invoker\ParameterResolver\ResolverChain;
+use Psr\Container\NotFoundExceptionInterface;
 
 /**
  * Compiled version of the dependency injection container.
@@ -112,4 +113,21 @@ protected function resolveFactory($callable, $entryName, array $extraParameters
             throw new InvalidDefinition("Entry \"$entryName\" cannot be resolved: " . $e->getMessage());
         }
     }
+
+    /**
+     * Resolve a placeholder in string definition
+     * - wrap possible NotFound exception to conform to the one from StringDefinition::resolveExpression.
+     */
+    protected function resolveStringPlaceholder($placeholder, $entryName)
+    {
+        try {
+            return $this->delegateContainer->get($placeholder);
+        } catch (NotFoundExceptionInterface $e) {
+            throw new DependencyException(sprintf(
+                "Error while parsing string expression for entry '%s': %s",
+                $entryName,
+                $e->getMessage()
+            ), 0, $e);
+        }
+    }
 }

src/Compiler/Compiler.php

@@ -214,9 +214,12 @@ private function compileDefinition(string $entryName, Definition $definition) :
                 }
                 break;
             case $definition instanceof StringDefinition:
-                $entryName = $this->compileValue($definition->getName());
-                $expression = $this->compileValue($definition->getExpression());
-                $code = 'return \DI\Definition\StringDefinition::resolveExpression(' . $entryName . ', ' . $expression . ', $this->delegateContainer);';
+                $expression = $definition->getExpression();
+                $callback = function (array $matches) use ($definition) {
+                    return '\'.$this->resolveStringPlaceholder(' . $this->compileValue($matches[1]) . ', ' . $this->compileValue($definition->getName()) . ').\'';
+                };
+                $value = preg_replace_callback('#\{([^\{\}]+)\}#', $callback, $expression);
+                $code = 'return \'' . $value . '\';';
                 break;
             case $definition instanceof EnvironmentVariableDefinition:
                 $variableName = $this->compileValue($definition->getVariableName());