/l.k, a limited sexpr interpreter
/arithmetic primitives are + - * %

P:.";"/" "\
E:{$[x~*x;x;(o@*x)/o'1_x]}
/E P"(* (+ 3 2) 4)"

/context: shadow made a simple lisp in haskael, and told me to make one in K
/{-# LANGUAGE LambdaCase #-}
/
/module Interpreter where
/
/import AST
/
/evalOp :: Operator -> Int -> Int -> Int
/evalOp = \case
/  Plus -> (+)
/  Minus -> (-)
/  Times -> (*)
/  Divided -> div
/
/eval :: Expr -> Int
/eval (Number n) = n
/eval (Call op args) = foldl1 (evalOp op) (eval <$> args)
/
/module Parser where
/
/import AST
/import Control.Applicative
/import Data.Functor
/import Text.Parsec (choice, ParseError, parse)
/import Text.Parsec.Char
/import Text.Parsec.Combinator (many1)
/import Text.Parsec.String (Parser)
/
/lexeme :: Parser a -> Parser a
/lexeme = (<* spaces)
/
/operator :: Parser Operator 
/operator = choice [
/  char '+' $> Plus,
/  char '-' $> Minus,
/  char '*' $> Times,
/  char '/' $> Divided ]
/
/number :: Parser Expr
/number = Number . read <$> many1 digit
/
/call :: Parser Expr
/call = do
/  lexeme $ char '('
/  op <- lexeme operator
/  args <- many1 $ lexeme expr
/  lexeme $ char ')' 
/  pure $ Call op args
/
/expr :: Parser Expr
/expr = number <|> call
/
/parseExpr :: String -> Either ParseError Expr
/parseExpr = parse expr ""

/I think we can all see how much superior K is
/"bUT yOU USeD evAL" suck it up no one said I couldn't

/the topic of just compiling to K came up
/what I made isn't a proper compiler to K, so here is one

PC:P@,/{$[+/x="+-*%";"\"",x,"\"";x]}'
C: {$[x~*x;$x;(*x),"[",(";"/o'1_x),"]"]}
/C PC"(* (+ 3 2) 4)"

~/languages/l.html