Visitor

hivecore.patterns.visitor(visitor_key: str | None = None) → Callable

Decorator to create a visitor class for visiting visitable classes.

Parameters:

visitor_key (str) – The key associated with the visitable classes to visit (default: class name).

Returns:

The decorated class acting as a visitor.

Return type:

class

Visitable

hivecore.patterns.visitable(*visitor_keys: str) → Callable

Decorator to mark a class as visitable by visitors.

Parameters:

visitor_keys (str) – The keys associated with the visitors that can visit the class.

Returns:

The decorated class.

Return type:

class

Example

To create visitable classes, use the @visitable decorator and specify the visitor keys associated with the class.

from hivecore.patterns import visitable

@visitable('Startup', 'Shutdown')
class CPU:
    pass

@visitable('Startup', 'Shutdown', 'Reset')
class Memory:
    pass

@visitable('Startup', 'Shutdown')
class Disk:
    pass

Creating Visitor Classes

To create visitor classes, use the @visitor decorator and specify the visitor key associated with the visitable classes to visit.

from hivecore.patterns import visitor

@visitor('Startup')
class StartOperation:
    pass

@visitor('Shutdown')
class ShutdownOperation:
    pass

@visitor('Reset')
class ResetOperation:
    pass

Visiting Visitable Classes

To visit the visitable classes, create instances of both visitable and visitor objects. Use the accept method of the visitable objects to accept a visitor.

# Create visitable and visitor objects
cpu = CPU()
memory = Memory()
disk = Disk()

startup = StartOperation()
shutdown = ShutdownOperation()
reset = ResetOperation()

# Use the accept method of the visitable objects
cpu.accept(startup)
cpu.accept(shutdown)
cpu.accept(reset)
memory.accept(reset)
disk.accept(startup)

Output

The output of the above example would be:

StartOperation visited CPU
ShutdownOperation visited CPU
ResetOperation visited an unknown visitable
ResetOperation visited Memory
StartOperation visited Disk