ppx_deriving Plugin for HardCaml

This module implements a plugin for the ppx_deriving rewriter that supports the HardCaml syntax:

• Provide a record annotation to generate helper functions
• Provide an optional bits attribute for signals
• Provide a required width attribute for list and array

Module interface

Original syntax:

module S : interface
  signal
  signal_list{ }
  signal_array{| |}
end

New syntax:

module S : sig
  type 'a t = {
    signal       : 'a;
    signal_list  : 'a list;
    signal_array : 'a array;
  } [@@deriving hardcaml]
end

Module implementation

Original syntax:

module S = interface
  signal[2]
  signal_list{2}[4]
  signal_array{|2|}[4]
end

New syntax:

module S = struct
  type 'a t = {
    signal       : 'a       [@bits 2];
    signal_list  : 'a list  [@length 2][@bits 4];
    signal_array : 'a array [@length 2][@bits 4];
  } [@@deriving hardcaml]
end

Options

• rtlprefix: prepend rtlprefix to the generated RTL name (string)
• rtlsuffix: append rtlsuffix to the generated RTL name (string)
• rtlmangle: when using interfaces, mangle the name of the interface and its signals (boolean)
• extends: list of interfaces to extend (list)