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#!/usr/bin/env python3
# SPDX-License-Identifier: 0BSD or CC0-1.0 or MIT-0 or Unlicense
# Copyright (c) 2023, Ryan Castellucci, No Rights Reserved

import io, sys
import datetime
import argparse
import requests
import operator
import struct

pervognsen

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#if defined(__x86_64__)
#define BREAK    asm("int3")
#else
#error Implement macros for your CPU.
#endif

pervognsen

A traditional table-based DFA implementation looks like this:

uint8_t table[NUM_STATES][256]

uint8_t run(const uint8_t *start, const uint8_t *end, uint8_t state) {
    for (const uint8_t *s = start; s != end; s++)
        state = table[state][*s];
    return state;
}

pervognsen

Multi-dimensional array views for systems programmers

As C programmers, most of us think of pointer arithmetic for multi-dimensional arrays in a nested way:

The address for a 1-dimensional array is base + x. The address for a 2-dimensional array is base + x + y*x_size for row-major layout and base + y + x*y_size for column-major layout. The address for a 3-dimensional array is base + x + (y + z*y_size)*x_size for row-column-major layout. And so on.