• 0 Posts
  • 112 Comments
Joined 2 years ago
Cake day: June 10th, 2024
  • balsoft@lemmy.mltoMemes@lemmy.ml•It's always about dat math
    1·
    22 days ago

    Nah, social division of labour is almost as old as civilization itself. It’s not possible to do everything by yourself, if you’re lucky enough not to die of hunger in a few weeks, you’ll die of a preventable disease within a few years.

    Capitalist exploitation of it (combined with faux individualism) is the issue.

    Translating to this scenario, there would be no issue if we had community kitchens with cheap/free food and well-paid workers. The issue is the capitalists extracting surplus value from a basic necessity, partly by convincing everyone to hate their neighbours and eat alone.

  • balsoft@lemmy.mltoProgrammer Humor@programming.dev•All modern digital infrastructure
    7·
    27 days ago

    The intended use-case is for bit-banging, i.e. sending electricity to places according to certain algorithms. Think about simple automation, like the control chip in your washing machine which executes the selected program by sending enable/disable signals to the water pump, valves, and the motor. Well, the same basic principles could apply to a lot of industrial processes and such, helping us rebuild the civilization.

    It would also be really fucking great for helping post-collapse engineers do various calculations. Those chips are really slow by modern standards, but insanely fast compared to an abacus, a slide rule, and a sheet of paper.

    BTW there’s also dusk OS, which follows similar principles but is targeted for more advanced hardware, like the abundant x86 and ARM chips. It has a way more user-friendly interface, a basic GUI, filesystem drivers, and IIRC even networking capabilities, all possible to run on a PC from the early 90s. It also has great bootstrapping flow, allowing you to rebuild itself from source, flash itself to other computers, and flash Collapse OS onto microcontrollers.

    Basically like a Linux install with all the dev-tools and sources already there, except much simpler, to the point that you probably can figure out how every component of the system works yourself, and fix issues when they happen. This knowledge will also directly translate into writing programs for collapse OS, because they share the programming language and many OS paradigms.

  • balsoft@lemmy.mltoProgrammer Humor@programming.dev•POV: You're a programmer
    17·
    2 months ago

    I decided to write it myself for fun. I decided that “From Scratch” means:

    • No parser libraries (parsec/happy/etc)
    • No using read from Prelude
    • No hacky meta-parsing

    Here is what I came up with (using my favourite parsing method: parser combinators):

    import Control.Monad ((>=>), replicateM)
import Control.Applicative (Alternative (..), asum, optional)
import Data.Maybe (fromMaybe)
import Data.Functor (($>))
import Data.List (singleton)
import Data.Map (Map, fromList)
import Data.Bifunctor (first, second)
import Data.Char (toLower, chr)

newtype Parser i o = Parser { parse :: i -> Maybe (i, o) } deriving (Functor)

instance Applicative (Parser i) where
  pure a = Parser $ \i -> Just (i, a)
  a <*> b = Parser $ parse a >=> \(i, f) -> second f <$> parse b i
instance Alternative (Parser i) where
  empty = Parser $ const Nothing
  a <|> b = Parser $ \i -> parse a i <|> parse b i
instance Monad (Parser i) where
  a >>= f = Parser $ parse a >=> \(i, b) -> parse (f b) i
instance Semigroup o => Semigroup (Parser i o) where
  a <> b = (<>) <$> a <*> b
instance Monoid o => Monoid (Parser i o) where
  mempty = pure mempty

type SParser = Parser String

charIf :: (a -> Bool) -> Parser [a] a
charIf cond = Parser $ \i -> case i of
  (x:xs) | cond x -> Just (xs, x)
  _ -> Nothing

char :: Eq a => a -> Parser [a] a
char c = charIf (== c)

one :: Parser i a -> Parser i [a]
one = fmap singleton

str :: Eq a => [a] -> Parser [a] [a]
str = mapM char

sepBy :: Parser i a -> Parser i b -> Parser i [a]
sepBy a b = (one a <> many (b *> a)) <|> mempty

data Decimal = Decimal { mantissa :: Integer, exponent :: Int } deriving Show

data JSON = Object (Map String JSON) | Array [JSON] | Bool Bool | Number Decimal | String String | Null deriving Show

whitespace :: SParser String
whitespace = many $ asum $ map char [' ', '\t', '\r', '\n']

digit :: Int -> SParser Int
digit base = asum $ take base [asum [char c, char (toLower c)] $> n | (c, n) <- zip (['0'..'9'] <> ['A'..'Z']) [0..]]

collectDigits :: Int -> [Int] -> Integer
collectDigits base = foldl (\acc x -> acc * fromIntegral base + fromIntegral x) 0

unsignedInteger :: SParser Integer
unsignedInteger = collectDigits 10 <$> some (digit 10)

integer :: SParser Integer
integer = asum [char '-' $> (-1), char '+' $> 1, str "" $> 1] >>= \sign -> (sign *) <$> unsignedInteger

-- This is the ceil of the log10 and also very inefficient
log10 :: Integer -> Int
log10 n
  | n < 1 = 0
  | otherwise = 1 + log10 (n `div` 10)

jsonNumber :: SParser Decimal
jsonNumber = do
  whole <- integer
  fraction <- fromMaybe 0 <$> optional (str "." *> unsignedInteger)
  e <- fromIntegral . fromMaybe 0 <$> optional ((str "E" <|> str "e") *> integer)
  pure $ Decimal (whole * 10^log10 fraction + signum whole * fraction) (e - log10 fraction)

escapeChar :: SParser Char
escapeChar = char '\\'
  *> asum [
    str "'" $> '\'',
    str "\"" $> '"',
    str "\\" $> '\\',
    str "n" $> '\n',
    str "r" $> '\r',
    str "t" $> '\t',
    str "b" $> '\b',
    str "f" $> '\f',
    str "u" *> (chr . fromIntegral . collectDigits 16 <$> replicateM 4 (digit 16))
  ]

jsonString :: SParser String
jsonString =
  char '"'
  *> many (asum [charIf (\c -> c /= '"' && c /= '\\'), escapeChar])
  <* char '"'

jsonObjectPair :: SParser (String, JSON)
jsonObjectPair = (,) <$> (whitespace *> jsonString <* whitespace <* char ':') <*> json

json :: SParser JSON
json =
  whitespace *>
    asum [
      Object <$> fromList <$> (char '{' *> jsonObjectPair `sepBy` char ',' <* char '}'),
      Array <$> (char '[' *> json `sepBy` char ',' <* char ']'),
      Bool <$> asum [str "true" $> True, str "false" $> False],
      Number <$> jsonNumber,
      String <$> jsonString,
      Null <$ str "null"
    ]
    <* whitespace

main :: IO ()
main = interact $ show . parse json

    This parses numbers as my own weird Decimal type, in order to preserve all information (converting to Double is lossy). I didn’t bother implementing any methods on the Decimal, because there are other libraries that do that and we’re just writing a parser.

    It’s also slow as hell but hey, that’s naive implementations for you!

    It ended up being 113 lines. I think I could reduce it a bit more if I was willing to sacrifice readability and/or just inline things instead of implementing stdlib typeclasses.