barafael

fn main() {
    println!("cargo:rustc-link-search=.");
    println!("cargo:rustc-link-lib=static=toggle");
}

barafael

"Easy to Use Correctly and Hard to Use Incorrectly" - The Typestate Pattern

How do you model a program so that it reflects real-world state, and that undesired or impossible states are unreachable?

Especially in safety-focused systems programming related to communication, interfaces, or I/O, the typestate pattern helps to ensure correctness and safety. Encoding state in type signatures exposes only valid transitions and operations. This reduces the need of runtime errors and even checks and leads to very pleasant APIs.

The Typestate Pattern in Rust

The Rust language has some unique features which enable downright beautiful typestate patterns. One idiomatic way to implement the state machine pattern is a struct with a generic parameter for each state. Such a StateMachine implements the operations of ``, and the initial state has a 'new' implementation. Transitions are realized by implementing `std::convert::From` (automagically implementing `std::convert::Into`). Due to the type sign

barafael

[dependencies]
cortex-m = "0.5.8"
cortex-m-rt = "0.6.7"
cortex-m-semihosting = "0.3.2"
panic-halt = "0.2.0"

stm32f4xx-hal =  { version = "0.5.0", features = ["stm32f407"]}

barafael

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

typedef struct {
    int matr;
    char *name;
    unsigned long isiks;
} student;

barafael

extern "C" {
    fn random() -> u64;
    fn time(n: u32) -> u32;
    fn srand(n: u32);
}

fn main() {
    unsafe {srand(time(0)) };
    println!("{}", unsafe{random()});
}

barafael

#include <math.h>

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

/*
 * Type punning - allowed in C, not in C++ (but works on gcc)
 */
typedef union {
    float content;

barafael

set shell=/bin/bash\ --login
set shell=bash

let g:python_host_prog  = '/usr/bin/python3'
let g:python2_host_prog  = '/usr/bin/python2'
let g:python3_host_prog = '/usr/bin/python3'

" '~' in path seems to not work?
call remote#host#RegisterPlugin('python3', '/home/ra/.local/share/nvim/plugged/neomake-platformio/rplugin/python/neomake-platformio.py', [
            \ {'sync': v:false, 'name': 'SetupPlatformioEnvironment', 'type': 'function', 'opts': {}},

barafael

const float LOWER_LIMIT = 655.36f * 40; // 40% duty cycle of 2.5ms signal is 1 ms
const float UPPER_LIMIT = 655.36f * 80; // 80% duty cycle of 2.5ms signal is 2 ms
const float RANGE = UPPER_LIMIT - LOWER_LIMIT;

#define OUT_PIN 6

void write(float throttle) {
    uint16_t value = LOWER_LIMIT + RANGE * throttle;
    analogWrite(OUT_PIN, value);
}

barafael

#include "Receiver.h"

Receiver receiver(8, 9, 10, 11);

uint16_t channels[4] = { 0 };

void setup() {
    Serial.begin(9600);
}

barafael

typedef enum {
    DMP_INIT_MEM_LOAD_FAILED,
    DMP_CONF_UPDATES_FAILED,
    DMP_ERROR_UNKNOWN
} error_type;

static const uint16_t BLINK_PERIOD = 500;

void blink_pattern(char pattern[]) {
    while(1) {