custom.md

External Generators

It's possible to implement custom generators without modifying HVCC. For this, you need to:

• subclass hvcc.types.compiler.Generator abstract class in your module (e.g. a Python file)
• add -G your_module_name command-line argument when executing hvcc

Tip

Maintain only one Generator subclass per module; otherwise any one of them may be executed unpredictably.

Check out hvcc.generators.c2daisy.c2daisy or hvcc.generators.c2dpf.c2dpf modules for reference implementations.

Example

This example demonstrates how to create a custom generator that prints a message into stdout.

This is example_hvcc_generator.py:

import time

from typing import Optional
from pathlib import Path

from hvcc.types.compiler import CompilerResp, ExternInfo, Generator
from hvcc.types.meta import Meta


class ExampleHvccGenerator(Generator):
    @classmethod
    def compile(
        cls,
        c_src_dir: Path,
        out_dir: Path,
        externs: ExternInfo,
        patch_name: str,
        patch_meta: Meta = Meta(),
        num_input_channels: int = 0,
        num_output_channels: int = 0,
        copyright: Optional[str] = None,
        verbose: Optional[bool] = False
    ) -> CompilerResp:
        begin_time = time.time()
        print("--> Invoking ExampleHvccGenerator")
        time.sleep(1)
        end_time = time.time()

        # Please see code example on how CompilerResp class is used and adapt to your case.
        return CompilerResp(
            stage='example_hvcc_generator',  # module name
            compile_time=end_time - begin_time,
            in_dir=c_src_dir,
            out_dir=out_dir
        )

With this file in your current directory, execute the following command:

hvcc patch.pd -G example_hvcc_generator