diff options
| -rw-r--r-- | app/Main.hs | 3 | ||||
| -rw-r--r-- | jotter.cabal | 15 | ||||
| -rw-r--r-- | package.yaml | 11 | ||||
| -rw-r--r-- | readme.md | 20 | ||||
| -rw-r--r-- | src/Lib.hs | 16 |
5 files changed, 27 insertions, 38 deletions
diff --git a/app/Main.hs b/app/Main.hs index 913bbb2..7a8bffa 100644 --- a/app/Main.hs +++ b/app/Main.hs @@ -1,3 +1,5 @@ +{-# LANGUAGE LambdaCase #-} + module Main ( main ) where @@ -18,6 +20,5 @@ main :: IO () main = do args <- getArgs case args of - -- ["transpile", path] -> transpile path ["reduce", path] -> reduce path _ -> putStrLn "Usage: jotter [transpile|reduce] <file>" diff --git a/jotter.cabal b/jotter.cabal index 2f7b480..c61e73d 100644 --- a/jotter.cabal +++ b/jotter.cabal @@ -50,18 +50,3 @@ executable jotter , containers , jotter default-language: Haskell2010 - -test-suite jotter-test - type: exitcode-stdio-1.0 - main-is: Spec.hs - other-modules: - Paths_jotter - hs-source-dirs: - test - ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N - build-depends: - async - , base >=4.7 && <5 - , containers - , jotter - default-language: Haskell2010 diff --git a/package.yaml b/package.yaml index 6d1c483..03236d2 100644 --- a/package.yaml +++ b/package.yaml @@ -49,14 +49,3 @@ executables: - -fllvm dependencies: - jotter - -tests: - jotter-test: - main: Spec.hs - source-dirs: test - ghc-options: - - -threaded - - -rtsopts - - -with-rtsopts=-N - dependencies: - - jotter @@ -1,7 +1,7 @@ # Jotter -Jotter (pronounced /dʒɑt.ər/) is a Turing tarpit and “an even better -Gödel-numbering” than its “sister language” +Jotter (pronounced /dʒɑt.ər/) is a Turing tarpit and an even better +Gödel-numbering than its sister language [Jot](https://esolangs.org/wiki/Jot). ## Semantics of Jotter @@ -13,18 +13,22 @@ Gödel-numbering” than its “sister language” [F1]ᵣ -> ([F]ₗK) `[F]` converts the Jotter program `F` to combinatory logic. The -associativity toggles between left and right (denoted by `ₗ/ᵣ`), -starting with the `ₗ` state. +associativity toggles between left and right (denoted by `ₗ/ᵣ`). + +The starting state depends on the length of the program: `ₗ` if +`len % 2 == 0` (even) and `ᵣ` if `len % 2 == 1` (odd). Don’t worry, this +only forces the core (the empty string, `I`) to always be on the left +side of the application. ## Jot vs. Jotter Jotter has exactly the same (regular) syntax as Jot, including support -of the null program. +for the null program. Every Jot program can easily be translated to Jotter: - [] -> -> I - [F0] -> ??? + [] -> -> I + [F0] -> [F]01 -> ([F]S) [F1] -> ??? -Therefore Jotter is *Turing complete*. +Therefore Jotter is *Turing-complete*. @@ -5,6 +5,7 @@ module Lib ) where import Term +import Utils data State = L | R @@ -17,13 +18,22 @@ k = Abs (Abs (Idx 1)) i :: Term i = Abs (Idx 0) +clean :: String -> String +clean (x : xs) | x == '0' || x == '1' = x : clean xs + | otherwise = clean xs +clean [] = [] + -- reverse wouldn't be needed if [0F] instead of [F0] -fromJotter :: String -> Term -fromJotter = go L . reverse +fromCleanJotter :: String -> Term +fromCleanJotter t | even $ length t = go L $ reverse t + | otherwise = go R $ reverse t where go L ('0' : xs) = App s (go R xs) go R ('0' : xs) = App (go L xs) s go L ('1' : xs) = App k (go R xs) go R ('1' : xs) = App (go L xs) k - go d (_ : xs) = go d xs go _ [] = i + go _ _ = invalid + +fromJotter :: String -> Term +fromJotter = fromCleanJotter . clean |