Command Line Subcommands in VHDL

Here’s the translation of the Go code to VHDL, with explanations in Markdown format suitable for Hugo:

Our program demonstrates how to implement command-line subcommands in VHDL. While VHDL is primarily used for hardware description, we’ll simulate the concept of command-line arguments and subcommands using procedures and records.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

entity CommandLineSubcommands is
end CommandLineSubcommands;

architecture Behavioral of CommandLineSubcommands is
    -- Simulate command-line arguments
    type arg_array is array (0 to 9) of string(1 to 20);
    signal args : arg_array := (others => (others => ' '));
    
    -- Simulate flags
    type foo_flags is record
        enable : boolean;
        name : string(1 to 20);
    end record;
    
    type bar_flags is record
        level : integer;
    end record;
    
    -- Procedures to simulate subcommands
    procedure foo_command(flags : in foo_flags; tail : in arg_array) is
    begin
        report "subcommand 'foo'";
        report "  enable: " & boolean'image(flags.enable);
        report "  name: " & flags.name;
        report "  tail: " & tail(0) & " " & tail(1);
    end procedure;
    
    procedure bar_command(flags : in bar_flags; tail : in arg_array) is
    begin
        report "subcommand 'bar'";
        report "  level: " & integer'image(flags.level);
        report "  tail: " & tail(0);
    end procedure;
    
begin
    process
        variable foo_flags_var : foo_flags := (enable => false, name => (others => ' '));
        variable bar_flags_var : bar_flags := (level => 0);
    begin
        -- Simulate parsing command-line arguments
        args(0) <= "foo               ";
        args(1) <= "-enable           ";
        args(2) <= "-name=joe         ";
        args(3) <= "a1                ";
        args(4) <= "a2                ";
        
        -- Check which subcommand is invoked
        if args(0) = "foo               " then
            -- Parse flags for foo subcommand
            foo_flags_var.enable := true;
            foo_flags_var.name := args(2)(7 to 9) & (10 to 20 => ' ');
            
            -- Call foo subcommand
            foo_command(foo_flags_var, args(3 to 4));
        elsif args(0) = "bar               " then
            -- Parse flags for bar subcommand
            bar_flags_var.level := 8; -- Simulated parsed value
            
            -- Call bar subcommand
            bar_command(bar_flags_var, args(3 to 3));
        else
            report "expected 'foo' or 'bar' subcommands" severity error;
        end if;
        
        wait;
    end process;
end Behavioral;

This VHDL code simulates the concept of command-line subcommands. We define records to represent the flags for each subcommand and procedures to handle the subcommand logic.

The main process simulates parsing command-line arguments and invoking the appropriate subcommand based on the first argument. Flags are “parsed” and passed to the subcommand procedures.

To run this VHDL code, you would typically use a VHDL simulator. The simulation will produce report messages that mimic the output of the original program.

Note that this is a simulation of the concept, as VHDL doesn’t have built-in support for command-line arguments or dynamic string handling like high-level programming languages. In a real VHDL project, you would typically use generics or constants to configure your design at compile-time rather than runtime arguments.

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Title here

Command Line Subcommands in VHDL