= What is it ? =

A Driver is something taking a [wiki:DsxWare Ware] and makeing somthing useful with it (typically generating source).

A Driver may be helped by [wiki:NodeDriver NodeDrivers], thus having a decentralized generation of products.

= Services =

Through class (ie even with no instance):
 * Keeps a list of known [wiki:NodeDriver NodeDrivers] and the associated [wiki:Node node] types. (see #Registering)
Through instances:
 * Has some parameters (output directory, optional featues, ...) chosen at instanciation
 * Keeps silent until code generation is asked (it may never be asked)

This way, we may generate with the same driver class (eg generate SystemC/Caba code) different [wiki:DsxWare Wares], with different options; or the other way around, generate the same [wiki:DsxWare Wares] many times through different backends.

= Registering =

With method `register()` a NodeDriver can register as a generation class for a [wiki:Node Node].
API between a Driver and its associated NodeDrivers is ad-hoc: the Driver's needs and design rules.

A base NodeDriver valid for a given Driver should be given, with basic functionalities, doing a no-op for the code.

= Registration usage =

Let's have the following class hierarchies:

{{{
Node
  MyWareTypeNode
    MyWareWidgetNode
    MyWareThingieNode
    MyWareOtherNode
}}}

Let's have the following drivers:

{{{
NodeDriver
  MyDriverNoopDriver
    MyWareWidgetNodeDriver
    MyWareOtherNodeDriver
}}}

Now, if we register in our new driver called `MyDriver`:
{{{
# default registration
MyDriver.register(MyWareTypeNode, MyWareWidgetNoopDriver)

# specialized drivers
MyDriver.register(MyWareWidgetNode, MyWareWidgetNodeDriver)
MyDriver.register(MyWareOtherNode, MyWareOtherNodeDriver)
}}}

`MyWareThingieNode` will be driven by `MyWareWidgetNoopDriver`.

This kind of walk through inherances also works with more childs and classes