Even more fluid code generation

I looked at
https://github.com/nikic/PHP-Parser/blob/master/doc/4_Code_generation.markdown

I think it could be even more fluid :)

This is a snippet from here,
https://github.com/Ocramius/ProxyManager/issues/36#issuecomment-16843161
(further down)
I wrote this without knowledge of PHP-Parser syntax, so I don't insist on the exact identifiers.

$engine = new GeneratorEngine(..);

$blueprint = $engine->newClassBlueprint();

$blueprint->extend(..);

// Start with an empty public non-abstract method, then enhance it.
$blueprint->addMethod('foo')
  ->setProtected()
  ->setArguments(..)
  ->setBody(..)
;

// This will automatically scan the interface for methods
$blueprint->implement(..);

// Take the signature directly from the interface
// The interface needs to be added *before* this.
$blueprint->overrideMethod('bar')
  ->setBody(..)
;

// Class name is not decided before the end.
// Decisions about file generation vs eval() are made in GeneratorEngine,
// we don't have to worry about it.
$reflectionClass = $blueprint->createAtName('MyClass');

// We now have a reflection class to work with.
$object = $reflectionClass->newInstance(..);

// Just for fun, we can create a copy of this class with a different name,
// and a different implementation of foo().

$blueprint->addMethodIfNotExists('foo')
  // Set the body to something else.
  ->setBody(..)
;

$blueprint->createAtName('AlternativeClass');

Read doc/4_Code_generation.markdown and compare its documented API with the proposed GeneratorEngine and blueprint flow. The issue does not identify implementation files or tests; work is not ready to start until the desired API and scope are decided, with completion defined by an agreed design and corresponding implementation.