Feat/user defined layers

[TimKoornstra]

Summary

This PR adds the ability to register and parse custom layers for both TensorFlow and PyTorch backends in VGSLify. It also introduces a few breaking changes related to file organization and simplifies import paths to make the library easier to use.

New Features

1. Custom Layer Registration (TensorFlow and PyTorch)

   • You can now register custom layer builder functions directly with the TensorFlowLayerFactoryand (similarly) with the Torch layer factory.

     from vgslify.tensorflow import TensorFlowLayerFactory
     
     @classmethod
     def register(cls, prefix: str, builder_fn):
         ...

   • Alternatively, use the new decorator approach:

     from vgslify.tensorflow import register_custom_layer
     
     @register_custom_layer("Xsw")
     def build_custom_layer(factory, spec):
         # Custom layer logic
         return tf.keras.layers.Dense(10)

   • This allows users to incorporate any custom TensorFlow or PyTorch layers into a VGSL specification simply by providing a prefix and builder function.

2. Custom Parser Registration for Model -> Spec

   • To convert a custom layer back into a VGSL specification, you can now register parser functions:

     from vgslify.model_parsers import register_custom_parser
     import tensorflow as tf
     
     class MyCustomLayer(tf.keras.layers.Layer):
         def __init__(self, units: int):
             super().__init__()
             self.units = units
     
     @register_custom_parser(MyCustomLayer)
     def parse_my_custom_layer(layer: MyCustomLayer):
         return f"MyCustomSpec({{layer.units}})"

   • These functions are then picked up automatically by the parser (TensorFlowModelParser or TorchModelParser) to handle custom layers.

Breaking Changes

1. Module Renaming and Reorganization

   • vgslify.parsers is now vgslify.model_parsers.
   • tf_parser.py, torch_parser.py, and base_parser.py have been reorganized into tensorflow/, torch/, and base/ directories respectively.
   • vgslify.core.parser is now called vgslify.core.spec_parser.

2. Simplified Imports

   • You can now import the main classes and utilities more directly:

     from vgslify import VGSLModelGenerator, model_to_spec

   • Parser imports have been simplified:

     from vgslify.tensorflow import TensorFlowModelParser
     from vgslify.torch import TorchModelParser

   • Layer factory imports have also been unified:

     from vgslify.tensorflow import TensorFlowLayerFactory, register_custom_layer

Example Usage

from vgslify import VGSLModelGenerator, model_to_spec
from vgslify.tensorflow import TensorFlowLayerFactory, register_custom_layer
from vgslify.model_parsers import register_custom_parser

# Register a custom layer builder
@register_custom_layer("Xsw")
def my_custom_builder(factory, spec):
    # Implement custom layer creation here
    return tf.keras.layers.Dense(10)

# Register a custom parser for that layer
@register_custom_parser(MyCustomLayer)
def my_custom_parser(layer):
    # Return the spec string for this custom layer
    return f"Xsw({{layer.units}})"

# Example model creation and spec conversion
model = ...
vgsl_spec = model_to_spec(model)