Static linking part 2

Also removes some broken list library functions

.gitignore

@@ -9,3 +9,4 @@
 WD
 bin/
 dist*
+.tricu_history

README.md

@@ -41,6 +41,16 @@ tricu > "(t (t (t t) (t t t)) (t t (t t t)))"
 tricu < -- or calculate its size (/demos/size.tri)
 tricu < size not?
 tricu > 12
+
+tricu < -- REPL Commands:
+tricu < !definitions  -- Lists all available definitions
+tricu < !output       -- Change output format (Tree, FSL, AST, etc.)
+tricu < !import       -- Import definitions from a file
+tricu < !exit         -- Exit the REPL
+tricu < !clear        -- ANSI screen clear
+tricu < !save         -- Save all REPL definitions to a file that you can !import
+tricu < !reset        -- Clear all REPL definitions
+tricu < !version      -- Print tricu version
 ```
 
 ## Installation and Use
@@ -84,6 +94,12 @@ tricu decode [OPTIONS]
                     Defaults to stdin.
 ```
 
+## Collaborating
+
+I am happy to accept issue reports, pull requests, or questions about tricu [via email](mailto:james@eversole.co).
+
+If you want to collaborate but don't want to email back-and-forth, please reach out via email once to let me know and I will provision a git.eversole.co account for you.
+
 ## Acknowledgements 
 
 Tree Calculus was discovered by [Barry Jay](https://github.com/barry-jay-personal/blog). 

demos/equality.tri

@@ -1,4 +1,5 @@
-!import "lib/base.tri" !Local
+!import "../lib/base.tri" !Local
+!import "../lib/list.tri" !Local
 
 main = lambdaEqualsTC
 

demos/levelOrderTraversal.tri

@@ -1,4 +1,5 @@
-!import "lib/base.tri" !Local
+!import "../lib/base.tri" Lib
+!import "../lib/list.tri" !Local
 
 main = exampleTwo
 -- Level Order Traversal of a labelled binary tree

demos/size.tri

@@ -1,4 +1,5 @@
-!import "lib/base.tri" !Local
+!import "../lib/base.tri" !Local
+!import "../lib/list.tri" !Local
 
 main = size size
 

demos/toSource.tri

@@ -1,4 +1,5 @@
-!import "lib/base.tri" !Local
+!import "../lib/base.tri" !Local
+!import "../lib/list.tri" !Local
 
 main = toSource not?
 -- Thanks to intensionality, we can inspect the structure of a given value

flake.lock

@@ -18,25 +18,55 @@
         "type": "github"
       }
     },
+    "nh2pkgs": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1718490232,
+        "narHash": "sha256-0Fh3aJZuTJVmiiKY/5SyvHlfhZ3HeZTDUQnd+Fx6/Qo=",
+        "type": "tarball",
+        "url": "https://github.com/nh2/nixpkgs/archive/ede5282c487a1fd2de64303ba59adad6726f1225.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://github.com/nh2/nixpkgs/archive/ede5282c487a1fd2de64303ba59adad6726f1225.tar.gz"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1734566935,
-        "narHash": "sha256-cnBItmSwoH132tH3D4jxmMLVmk8G5VJ6q/SC3kszv9E=",
+        "lastModified": 1738797219,
+        "narHash": "sha256-KRwX9Z1XavpgeSDVM/THdFd6uH8rNm/6R+7kIbGa+2s=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "087408a407440892c1b00d80360fd64639b8091d",
+        "rev": "1da52dd49a127ad74486b135898da2cef8c62665",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "type": "github"
+        "id": "nixpkgs",
+        "type": "indirect"
       }
     },
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
+        "nh2pkgs": "nh2pkgs",
+        "nixpkgs": "nixpkgs",
+        "static-haskell-nix": "static-haskell-nix"
+      }
+    },
+    "static-haskell-nix": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1718492291,
+        "narHash": "sha256-XbBHPJk3ln+uLW+Dsio7vJNYnsHhmqenbI7cLsP8kHg=",
+        "owner": "nh2",
+        "repo": "static-haskell-nix",
+        "rev": "481e7d73ca624278ef0f840a0a2ba09e3a583217",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nh2",
+        "repo": "static-haskell-nix",
+        "type": "github"
       }
     },
     "systems": {

flake.nix

@@ -2,45 +2,56 @@
   description = "tricu";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
+    nh2pkgs = {
+      url = "https://github.com/nh2/nixpkgs/archive/ede5282c487a1fd2de64303ba59adad6726f1225.tar.gz";
+      type = "tarball";
+      flake = false;
+    };
+    static-haskell-nix = {
+      url = "github:nh2/static-haskell-nix";
+      flake = false;
+    };
     flake-utils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, flake-utils, nh2pkgs, nixpkgs, static-haskell-nix }:
     flake-utils.lib.eachDefaultSystem (system:
       let
-        pkgs              = nixpkgs.legacyPackages.${system};
-        packageName       = "tricu";
-        containerPackageName = "${packageName}-container";
+        compiler = "ghc948";
+        packageName = "tricu";
 
-        customGHC = pkgs.haskellPackages.ghcWithPackages (hpkgs: with hpkgs; [
-          megaparsec
-        ]);
+        overlay = self: super: {
+          haskell = super.haskell // {
+            packages = super.haskell.packages // {
+              ${compiler} = super.haskell.packages.${compiler}.override {
+                overrides = final: prev: {
+                  ${packageName} = prev.callCabal2nix packageName ./. {};
+                };
+              };
+            };
+          };
+        };
 
-        haskellPackages = pkgs.haskellPackages;
+        overlays = [overlay];
 
-        enableSharedExecutables = false;
-        enableSharedLibraries = false;
+        pkgs = import nh2pkgs { inherit overlays system; };
+
+        survey = import "${static-haskell-nix}/survey" { inherit compiler pkgs; };
+
+        tricuStatic = survey.haskellPackages.${packageName};
 
-        tricu = pkgs.haskell.lib.justStaticExecutables self.packages.${system}.default;
       in {
-
-        packages.${packageName} =
-          haskellPackages.callCabal2nix packageName self rec {};
-
-        packages.default = self.packages.${system}.${packageName};
-        defaultPackage = self.packages.${system}.default;
+        packages.default = tricuStatic;
 
         devShells.default = pkgs.mkShell {
-          buildInputs = with pkgs; [
+          buildInputs = with survey; [
             haskellPackages.cabal-install
+            haskellPackages.ghc-events
             haskellPackages.ghcid
-            customGHC
-            upx
-          ];
+          ] ++ [pkgs.upx];
           inputsFrom = builtins.attrValues self.packages.${system};
         };
         devShell = self.devShells.${system}.default;
-
       });
 }
+

lib/base.tri

@@ -1,13 +1,8 @@
 false = t
 _     = t
 true  = t t
-k     = t t
-i     = t (t k) t
-s     = t (t (k t)) t
-m     = s i i
-b     = s (k s) k
-c     = s (s (k s) (s (k k) s)) (k k)
 id    = \a : a
+const = \a b : a
 pair  = t
 if    = \cond then else : t (t else (t t then)) t cond
 
@@ -26,28 +21,6 @@ matchBool = (\ot of : triage
   (\_ _ : ot)
 )
 
-matchList = \a b : triage a _ b
-
-matchPair = \a   : triage _ _ a
-
-not? = matchBool false true
-and? = matchBool id (\_ : false)
-emptyList? = matchList true (\_ _ : false)
-
-head = matchList t (\head _ : head)
-tail = matchList t (\_ tail : tail)
-
-or? = (\x y : 
-	matchBool 
-  	(matchBool (t t) (t t) y)
-  	(matchBool (t t) 0 y)
-  	x)
-xor? = matchBool id not?
-
-append = y (\self : matchList
-  (\k : k)
-  (\h r k : pair h (self r k)))
-
 lAnd = (triage
   (\_     : false)
   (\_ x   : x)
@@ -58,11 +31,22 @@ lOr = (triage
   (\_ _   : true)
   (\_ _ _ : true))
 
-map_ = y (\self :
-  matchList
-    (\_ : t)
-    (\head tail f : pair (f head) (self tail f)))
-map = \f l : map_ l f
+matchPair = \a : triage _ _ a
+
+not? = matchBool false true
+and? = matchBool id (\_ : false)
+
+or? = (\x z : 
+  matchBool 
+    (matchBool true true z)
+    (matchBool true false z)
+    x)
+
+xor? = (\x z : 
+  matchBool 
+    (matchBool false true z)
+    (matchBool true false z)
+    x)
 
 equal? = y (\self : triage
   (triage
@@ -80,21 +64,6 @@ equal? = y (\self : triage
       (\_ : false)
       (\bx by : lAnd (self ax bx) (self ay by))))
 
-lExist? = y (\self x : matchList
-  false
-  (\h z : or? (equal? x h) (self x z)))
-
-filter_ = y (\self : matchList
-  (\_ : t)
-  (\head tail f : matchBool (t head) i (f head) (self tail f)))
-filter  = \f l : filter_ l f
-
-foldl_ = y (\self f l x : matchList (\acc : acc) (\head tail acc : self f tail (f acc head)) l x)
-foldl  = \f x l : foldl_ f l x
-
-foldr_ = y (\self x f l : matchList x (\head tail : f (self x f tail) head) l)
-foldr  = \f x l : foldr_ x f l
-
 succ = y (\self :
   triage
     1
@@ -103,48 +72,3 @@ succ = y (\self :
       (t (t t))
       (\_ tail : t t (self tail))
       t))
-
-length = y (\self : matchList
-  0
-  (\_ tail : succ (self tail)))
-
-reverse = y (\self : matchList
-  t
-  (\head tail : append (self tail) (pair head t)))
-
-snoc = y (\self x : matchList
-  (pair x t)
-  (\h z : pair h (self x z)))
-
-count = y (\self x : matchList
-  0
-  (\h z : matchBool 
-    (succ (self x z))
-    (self x z)
-    (equal? x h)))
-
-last = y (\self : matchList
-  t
-  (\hd tl : matchBool
-    hd
-    (self tl)
-    (emptyList? tl)))
-
-all? = y (\self pred : matchList
-  true
-  (\h z : and? (pred h) (self pred z)))
-
-any? = y (\self pred : matchList
-  false
-  (\h z : or? (pred h) (self pred z)))
-
-unique_ = y (\self seen : matchList
-  t
-  (\head rest : matchBool
-    (self seen rest)
-    (pair head (self (pair head seen) rest))
-    (lExist? head seen)))
-unique = \xs : unique_ t xs
-
-intersect = \xs ys : filter (\x : lExist? x ys) xs
-union     = \xs ys : unique (append xs ys)

lib/list.tri

@@ -0,0 +1,68 @@
+!import "base.tri" !Local
+
+matchList = \a b : triage a _ b
+
+emptyList? = matchList true (\_ _ : false)
+head = matchList t (\head _ : head)
+tail = matchList t (\_ tail : tail)
+
+append = y (\self : matchList
+  (\k : k)
+  (\h r k : pair h (self r k)))
+
+lExist? = y (\self x : matchList
+  false
+  (\h z : or? (equal? x h) (self x z)))
+
+map_ = y (\self :
+  matchList
+    (\_ : t)
+    (\head tail f : pair (f head) (self tail f)))
+map = \f l : map_ l f
+
+filter_ = y (\self : matchList
+  (\_ : t)
+  (\head tail f : matchBool (t head) id (f head) (self tail f)))
+filter  = \f l : filter_ l f
+
+foldl_ = y (\self f l x : matchList (\acc : acc) (\head tail acc : self f tail (f acc head)) l x)
+foldl  = \f x l : foldl_ f l x
+
+foldr_ = y (\self x f l : matchList x (\head tail : f (self x f tail) head) l)
+foldr  = \f x l : foldr_ x f l
+
+length = y (\self : matchList
+  0
+  (\_ tail : succ (self tail)))
+
+reverse = y (\self : matchList
+  t
+  (\head tail : append (self tail) (pair head t)))
+
+snoc = y (\self x : matchList
+  (pair x t)
+  (\h z : pair h (self x z)))
+
+count = y (\self x : matchList
+  0
+  (\h z : matchBool
+    (succ (self x z))
+    (self x z)
+    (equal? x h)))
+
+last = y (\self : matchList
+  t
+  (\hd tl : matchBool
+    hd
+    (self tl)
+    (emptyList? tl)))
+
+all? = y (\self pred : matchList
+  true
+  (\h z : and? (pred h) (self pred z)))
+
+any? = y (\self pred : matchList
+  false
+  (\h z : or? (pred h) (self pred z)))
+
+intersect = \xs ys : filter (\x : lExist? x ys) xs

lib/patterns.tri

@@ -0,0 +1,36 @@
+!import "list.tri" !Local
+
+match_ = y (\self value patterns :
+  triage
+    t
+    (\_ : t)
+    (\pattern rest :
+      triage
+        t
+        (\_ : t)
+        (\test result :
+          if (test value)
+             (result value)
+             (self value rest))
+        pattern)
+    patterns)
+
+match = (\value patterns :
+  match_ value (map (\sublist :
+    pair (head sublist) (head (tail sublist)))
+    patterns))
+
+otherwise = const (t t)
+
+matchExample = (\x : match x
+  [[(equal? 1)  (\_ : "one")]
+  [(equal? 2)  (\_ : "two")]
+  [(equal? 3)  (\_ : "three")]
+  [(equal? 4)  (\_ : "four")]
+  [(equal? 5)  (\_ : "five")]
+  [(equal? 6)  (\_ : "six")]
+  [(equal? 7)  (\_ : "seven")]
+  [(equal? 8)  (\_ : "eight")]
+  [(equal? 9)  (\_ : "nine")]
+  [(equal? 10) (\_ : "ten")]
+  [ otherwise  (\_ : "I ran out of fingers!")]])

src/Eval.hs

@@ -19,16 +19,16 @@ evalSingle env term
       Nothing ->
         let res = evalAST env body
         in Map.insert "!result" res (Map.insert name res env)
-  | SApp func arg <- term 
+  | SApp func arg <- term
   = let res = apply (evalAST env func) (evalAST env arg)
       in Map.insert "!result" res env
-  | SVar name <- term 
+  | SVar name <- term
   = case Map.lookup name env of
         Just v  -> Map.insert "!result" v env
         Nothing ->
           errorWithoutStackTrace $ "Variable `" ++ name ++ "` not defined\n\
           \This error should never occur here. Please report this as an issue."
-  | otherwise 
+  | otherwise
   = Map.insert "!result" (evalAST env term) env
 
 evalTricu :: Env -> [TricuAST] -> Env
@@ -75,6 +75,9 @@ elimLambda = go
     go (SLambda [f] (SLambda [g] (SLambda [x] body)))
       | body == SApp (SVar f) (SApp (SVar g) (SVar x)) = _B
     -- General elimination
+    go (SLambda [v] (SList xs))
+      = elimLambda (SLambda [v] (foldr wrapTLeaf TLeaf xs))
+        where wrapTLeaf m r = SApp (SApp TLeaf m) r
     go (SLambda (v:vs) body)
       | null vs                    = toSKI v (elimLambda body)
       | otherwise                  = elimLambda (SLambda [v] (SLambda vs body))
@@ -141,18 +144,23 @@ reorderDefs env defs
 
 buildDepGraph :: [TricuAST] -> Map.Map String (Set.Set String)
 buildDepGraph topDefs
-  | not (null duplicateNames) =
+  | not (null conflictingDefs) =
       errorWithoutStackTrace $
-        "Duplicate definitions detected: " ++ show duplicateNames
+        "Conflicting definitions detected: " ++ show conflictingDefs
   | otherwise =
       Map.fromList
         [ (name, depends topDefs (SDef name [] body))
         | SDef name _ body <- topDefs]
   where
-    names = [name | SDef name _ _ <- topDefs]
-    duplicateNames =
-      [ name | (name, count) <- Map.toList (countOccurrences names) , count > 1]
-    countOccurrences = foldr (\x -> Map.insertWith (+) x 1) Map.empty
+    defsMap = Map.fromListWith (++)
+      [(name, [(name, body)]) | SDef name _ body <- topDefs]
+
+    conflictingDefs =
+      [ name
+      | (name, defs) <- Map.toList defsMap
+      , let bodies = map snd defs
+      , not $ all (== head bodies) (tail bodies)
+      ]
 
 sortDeps :: Map.Map String (Set.Set String) -> [String]
 sortDeps graph = go [] Set.empty (Map.keys graph)

src/FileEval.hs

@@ -6,12 +6,34 @@ import Parser
 import Research
 
 import Data.List       (partition)
+import Data.Maybe      (mapMaybe)
 import Control.Monad   (foldM)
 import System.IO
+import System.FilePath (takeDirectory, normalise, (</>))
 
 import qualified Data.Map as Map
 import qualified Data.Set as Set
 
+extractMain :: Env -> Either String T
+extractMain env =
+  case Map.lookup "main" env of
+    Just result -> Right result
+    Nothing -> Left "No `main` function detected"
+
+processImports :: Set.Set FilePath -> FilePath -> FilePath -> [TricuAST]
+                 -> Either String ([TricuAST], [(FilePath, String, FilePath)])
+processImports seen base currentPath asts =
+  let (imports, nonImports) = partition isImp asts
+      importPaths = mapMaybe getImportInfo imports
+  in if currentPath `Set.member` seen
+     then Left $ "Encountered cyclic import: " ++ currentPath
+     else Right (nonImports, importPaths)
+  where
+    isImp (SImport _ _) = True
+    isImp _ = False
+    getImportInfo (SImport p n) = Just (p, n, makeRelativeTo currentPath p)
+    getImportInfo _ = Nothing
+
 evaluateFileResult :: FilePath -> IO T
 evaluateFileResult filePath = do
   contents <- readFile filePath
@@ -19,11 +41,11 @@ evaluateFileResult filePath = do
   case parseProgram tokens of
     Left err -> errorWithoutStackTrace (handleParseError err)
     Right ast -> do
-      ast <- preprocessFile filePath
-      let finalEnv = evalTricu Map.empty ast
-      case Map.lookup "main" finalEnv of
-        Just finalResult -> return finalResult
-        Nothing -> errorWithoutStackTrace "No `main` function detected"
+      processedAst <- preprocessFile filePath
+      let finalEnv = evalTricu Map.empty processedAst
+      case extractMain finalEnv of
+        Right result -> return result
+        Left err -> errorWithoutStackTrace err
 
 evaluateFile :: FilePath -> IO Env
 evaluateFile filePath = do
@@ -46,38 +68,33 @@ evaluateFileWithContext env filePath = do
       pure $ evalTricu env ast
 
 preprocessFile :: FilePath -> IO [TricuAST]
-preprocessFile = preprocessFile' Set.empty
+preprocessFile p = preprocessFile' Set.empty p p
 
-preprocessFile' :: Set.Set FilePath -> FilePath -> IO [TricuAST]
-preprocessFile' inProgress filePath
-  | filePath `Set.member` inProgress = 
-      errorWithoutStackTrace $ "Encountered cyclic import: " ++ filePath
-  | otherwise = do
-      contents <- readFile filePath
-      let tokens = lexTricu contents
-      case parseProgram tokens of
-        Left err -> errorWithoutStackTrace (handleParseError err)
-        Right asts -> do
-          let (imports, nonImports) = partition isImport asts
-          let newInProgress = Set.insert filePath inProgress
-          importedASTs <- concat <$> 
-            mapM (processImport newInProgress "") imports
-          pure $ importedASTs ++ nonImports
+preprocessFile' :: Set.Set FilePath -> FilePath -> FilePath -> IO [TricuAST]
+preprocessFile' seen base currentPath = do
+  contents <- readFile currentPath
+  let tokens = lexTricu contents
+  case parseProgram tokens of
+    Left err -> errorWithoutStackTrace (handleParseError err)
+    Right ast ->
+      case processImports seen base currentPath ast of
+        Left err -> errorWithoutStackTrace err
+        Right (nonImports, importPaths) -> do
+          let seen' = Set.insert currentPath seen
+          imported <- concat <$> mapM (processImportPath seen' base) importPaths
+          pure $ imported ++ nonImports
   where
-    isImport :: TricuAST -> Bool
-    isImport (SImport _ _) = True
-    isImport _             = False
+    processImportPath seen base (path, name, importPath) = do
+      ast <- preprocessFile' seen base importPath
+      pure $ map (nsDefinition (if name == "!Local" then "" else name))
+           $ filter (not . isImp) ast
+    isImp (SImport _ _) = True
+    isImp _ = False
 
-    processImport :: Set.Set FilePath -> String -> TricuAST -> IO [TricuAST]
-    processImport prog currentModule (SImport path "!Local") = do
-      ast <- preprocessFile' prog path
-      let defs = filter (not . isImport) ast
-      pure $ map (nsDefinition currentModule) defs
-    processImport prog _ (SImport path name) = do
-      ast <- preprocessFile' prog path
-      let defs = filter (not . isImport) ast
-      pure $ map (nsDefinition name) defs
-    processImport _ _ _ = error "Unexpected non-import in processImport"
+makeRelativeTo :: FilePath -> FilePath -> FilePath
+makeRelativeTo f i =
+    let d = takeDirectory f
+    in normalise $ d </> i
 
 nsDefinitions :: String -> [TricuAST] -> [TricuAST]
 nsDefinitions moduleName = map (nsDefinition moduleName)
@@ -86,7 +103,7 @@ nsDefinition :: String -> TricuAST -> TricuAST
 nsDefinition "" def = def
 nsDefinition moduleName (SDef name args body)
   | isPrefixed name = SDef name args (nsBody moduleName body)
-  | otherwise = SDef (nsVariable moduleName name) 
+  | otherwise = SDef (nsVariable moduleName name)
                         args (nsBody moduleName body)
 nsDefinition moduleName other =
   nsBody moduleName other
@@ -107,7 +124,7 @@ nsBody moduleName (TStem subtree) =
   TStem (nsBody moduleName subtree)
 nsBody moduleName (SDef name args body)
   | isPrefixed name = SDef name args (nsBody moduleName body)
-  | otherwise = SDef (nsVariable moduleName name) 
+  | otherwise = SDef (nsVariable moduleName name)
                         args (nsBody moduleName body)
 nsBody _ other = other
 
@@ -117,19 +134,19 @@ nsBodyScoped moduleName args body = case body of
     if name `elem` args
       then SVar name
       else nsBody moduleName (SVar name)
-  SApp func arg -> 
+  SApp func arg ->
     SApp (nsBodyScoped moduleName args func) (nsBodyScoped moduleName args arg)
-  SLambda innerArgs innerBody -> 
+  SLambda innerArgs innerBody ->
     SLambda innerArgs (nsBodyScoped moduleName (args ++ innerArgs) innerBody)
-  SList items -> 
+  SList items ->
     SList (map (nsBodyScoped moduleName args) items)
-  TFork left right -> 
-    TFork (nsBodyScoped moduleName args left) 
+  TFork left right ->
+    TFork (nsBodyScoped moduleName args left)
           (nsBodyScoped moduleName args right)
-  TStem subtree -> 
+  TStem subtree ->
     TStem (nsBodyScoped moduleName args subtree)
   SDef name innerArgs innerBody ->
-    SDef (nsVariable moduleName name) innerArgs 
+    SDef (nsVariable moduleName name) innerArgs
          (nsBodyScoped moduleName (args ++ innerArgs) innerBody)
   other -> other
 

src/Lexer.hs

@@ -3,6 +3,7 @@ module Lexer where
 import Research
 
 import Control.Monad               (void)
+import Data.Functor                (($>))
 import Data.Void
 import Text.Megaparsec
 import Text.Megaparsec.Char hiding (space)
@@ -54,16 +55,16 @@ lexTricu input = case runParser tricuLexer "" input of
 
 
 keywordT :: Lexer LToken
-keywordT = string "t" *> notFollowedBy alphaNumChar *> pure LKeywordT
+keywordT = string "t" *> notFollowedBy alphaNumChar $> LKeywordT
 
 identifier :: Lexer LToken
 identifier = do
   first <- lowerChar <|> char '_'
-  rest  <- many $ letterChar 
+  rest  <- many $ letterChar
               <|> digitChar <|> char '_' <|> char '-' <|> char '?'
               <|> char '$'  <|> char '#' <|> char '@' <|> char '%'
   let name = first : rest
-  if (name == "t" || name == "!result")
+  if name == "t" || name == "!result"
     then fail "Keywords (`t`, `!result`) cannot be used as an identifier"
     else return (LIdentifier name)
 
@@ -76,7 +77,7 @@ namespace = do
   return (LNamespace name)
 
 dot :: Lexer LToken
-dot = char '.' *> pure LDot
+dot = char '.' $> LDot
 
 lImport :: Lexer LToken
 lImport = do
@@ -88,28 +89,28 @@ lImport = do
   return (LImport path name)
 
 assign :: Lexer LToken
-assign = char '=' *> pure LAssign
+assign = char '=' $> LAssign
 
 colon :: Lexer LToken
-colon = char ':' *> pure LColon
+colon = char ':' $> LColon
 
 backslash :: Lexer LToken
-backslash = char '\\' *> pure LBackslash
+backslash = char '\\' $> LBackslash
 
 openParen :: Lexer LToken
-openParen = char '(' *> pure LOpenParen
+openParen = char '(' $> LOpenParen
 
 closeParen :: Lexer LToken
-closeParen = char ')' *> pure LCloseParen
+closeParen = char ')' $> LCloseParen
 
 openBracket :: Lexer LToken
-openBracket = char '[' *> pure LOpenBracket
+openBracket = char '[' $> LOpenBracket
 
 closeBracket :: Lexer LToken
-closeBracket = char ']' *> pure LCloseBracket
+closeBracket = char ']' $> LCloseBracket
 
 lnewline :: Lexer LToken
-lnewline = char '\n' *> pure LNewline
+lnewline = char '\n' $> LNewline
 
 sc :: Lexer ()
 sc = space

src/Parser.hs

@@ -3,12 +3,12 @@ module Parser where
 import Lexer
 import Research
 
-import Control.Monad (void)
+import Control.Monad             (void)
 import Control.Monad.State
-import Data.List.NonEmpty (toList)
-import Data.Void (Void)
+import Data.List.NonEmpty        (toList)
+import Data.Void                 (Void)
 import Text.Megaparsec
-import Text.Megaparsec.Error (ParseErrorBundle, errorBundlePretty)
+import Text.Megaparsec.Error     (ParseErrorBundle, errorBundlePretty)
 import qualified Data.Set as Set
 
 data PState = PState
@@ -255,9 +255,9 @@ parseSingleItemM = do
 
 parseVarM :: ParserM TricuAST
 parseVarM = do
-  token <- satisfyM (\case 
+  token <- satisfyM (\case
     LNamespace _ -> True
-    LIdentifier _ -> True 
+    LIdentifier _ -> True
     _ -> False)
   case token of
     LNamespace ns -> do

src/REPL.hs

@@ -6,75 +6,186 @@ import Lexer
 import Parser
 import Research
 
-import Control.Exception      (SomeException, catch)
-import Control.Monad.IO.Class (liftIO)
-import Control.Monad.Catch    (handle, MonadCatch)
-import Data.Char              (isSpace)
-import Data.List              ( dropWhile
-                              , dropWhileEnd
-                              , intercalate
-                              , isPrefixOf)
+import Control.Exception         (IOException, SomeException, catch, displayException)
+import Control.Monad             (forM_)
+import Control.Monad.IO.Class    (liftIO)
+import Control.Monad.Catch       (handle, MonadCatch)
+import Control.Monad.Trans.Class (lift)
+import Control.Monad.Trans.Maybe (MaybeT(..), runMaybeT)
+import Data.Char                 (isSpace, isUpper)
+import Data.List                 ( dropWhile
+                                 , dropWhileEnd
+                                 , isPrefixOf)
 import System.Console.Haskeline
+import Paths_tricu (version)
+import Data.Version (showVersion)
+import qualified Data.Text as T
+import qualified Data.Text.IO as T
 
 import qualified Data.Map as Map
 
 repl :: Env -> IO ()
-repl env = runInputT defaultSettings (withInterrupt (loop env True))
+repl env = runInputT settings (withInterrupt (loop env Decode))
   where
-    loop :: Env -> Bool -> InputT IO ()
-    loop env decode = handle (interruptHandler env decode) $ do
+    settings :: Settings IO
+    settings = Settings
+      { complete = completeWord Nothing " \t" completeCommands
+      , historyFile = Just "~/.local/state/tricu/history"
+      , autoAddHistory = True
+      }
+
+    completeCommands :: String -> IO [Completion]
+    completeCommands str = return $ map simpleCompletion $
+      filter (str `isPrefixOf`) commands
+      where
+        commands = [ "!exit"
+                   , "!output"
+                   , "!definitions"
+                   , "!import"
+                   , "!clear"
+                   , "!save"
+                   , "!reset"
+                   , "!version"
+                   ]
+
+    loop :: Env -> EvaluatedForm -> InputT IO ()
+    loop env form = handle (interruptHandler env form) $ do
       minput <- getInputLine "tricu < "
       case minput of
         Nothing -> outputStrLn "Exiting tricu"
         Just s
-          | strip s == "" -> loop env decode
+          | strip s == "" -> loop env form
           | strip s == "!exit" -> outputStrLn "Exiting tricu"
-          | strip s == "!decode" -> do
-              outputStrLn $ "Decoding " ++ (if decode then "disabled" else "enabled")
-              loop env (not decode)
-          | "!import" `isPrefixOf` strip s -> do
-              let afterImport = dropWhile (== ' ') $ drop (length ("!import" :: String)) (strip s)
-              if not (null afterImport)
-                then outputStrLn "Warning: REPL imports are interactive; \
-                                  \additional arguments are ignored."
-                else pure ()
-              path <- getInputLine "File path to load < "
-              case path of
-                Nothing -> do
-                  outputStrLn "No input received; stopping import."
-                  loop env decode
-                Just p -> do
-                  loadedEnv <- liftIO $ evaluateFileWithContext env
-                    (strip p) `catch` \e -> errorHandler env e
-                  loop (Map.delete "!result" (Map.union loadedEnv env)) decode
-          | take 2 s == "--" -> loop env decode
+          | strip s == "!clear" -> do
+              liftIO $ putStr "\ESC[2J\ESC[H"
+              loop env form
+          | strip s == "!reset" -> do
+              outputStrLn "Environment reset to initial state"
+              loop Map.empty form
+          | strip s == "!version" -> do
+              outputStrLn $ "tricu version " ++ showVersion version
+              loop env form
+          | "!save" `isPrefixOf` strip s -> handleSave env form
+          | strip s == "!output" -> handleOutput env form
+          | strip s == "!definitions" -> do
+              let defs = Map.keys $ Map.delete "!result" env
+              if null defs
+                then outputStrLn "No definitions discovered."
+                else do
+                  outputStrLn "Available definitions:"
+                  mapM_ outputStrLn defs
+              loop env form
+          | "!import" `isPrefixOf` strip s -> handleImport env form
+          | take 2 s == "--" -> loop env form
           | otherwise -> do
-              newEnv <- liftIO $ processInput env s decode `catch` errorHandler env
-              loop newEnv decode
+              newEnv <- liftIO $ processInput env s form `catch` errorHandler env
+              loop newEnv form
 
-    interruptHandler :: Env -> Bool -> Interrupt -> InputT IO ()
-    interruptHandler env decode _ = do
+    handleOutput :: Env -> EvaluatedForm -> InputT IO ()
+    handleOutput env currentForm = do
+      let formats = [Decode, TreeCalculus, FSL, AST, Ternary, Ascii]
+      outputStrLn "Available output formats:"
+      mapM_ (\(i, f) -> outputStrLn $ show i ++ ". " ++ show f)
+        (zip [1..] formats)
+
+      result <- runMaybeT $ do
+        input <- MaybeT $ getInputLine "Select output format (1-6) < "
+        case reads input of
+          [(n, "")] | n >= 1 && n <= 6 ->
+            return $ formats !! (n-1)
+          _ -> MaybeT $ return Nothing
+
+      case result of
+        Nothing -> do
+          outputStrLn "Invalid selection. Keeping current output format."
+          loop env currentForm
+        Just newForm -> do
+          outputStrLn $ "Output format changed to: " ++ show newForm
+          loop env newForm
+
+    handleImport :: Env -> EvaluatedForm -> InputT IO ()
+    handleImport env form = do
+      res <- runMaybeT $ do
+        let fset = setComplete completeFilename defaultSettings
+        path <- MaybeT $ runInputT fset $
+          getInputLineWithInitial "File path to load < " ("", "")
+
+        text <- MaybeT $ liftIO $ handle (\e -> do
+            putStrLn $ "Error reading file: " ++ displayException (e :: IOException)
+            return Nothing
+          ) $ Just <$> readFile (strip path)
+
+        case parseProgram (lexTricu text) of
+          Left err -> do
+            lift $ outputStrLn $ "Parse error: " ++ handleParseError err
+            MaybeT $ return Nothing
+          Right ast -> do
+            ns <- MaybeT $ runInputT defaultSettings $
+              getInputLineWithInitial "Namespace (or !Local for no namespace) < " ("", "")
+
+            let name = strip ns
+            if (name /= "!Local" && (null name || not (isUpper (head name)))) then do
+                lift $ outputStrLn "Namespace must start with an uppercase letter"
+                MaybeT $ return Nothing
+            else do
+                prog <- liftIO $ preprocessFile (strip path)
+                let code = case name of
+                      "!Local" -> prog
+                      _ -> nsDefinitions name prog
+                    env' = evalTricu env code
+                return env'
+      case res of
+        Nothing -> do
+          outputStrLn "Import cancelled"
+          loop env form
+        Just env' ->
+          loop (Map.delete "!result" env') form
+
+    interruptHandler :: Env -> EvaluatedForm -> Interrupt -> InputT IO ()
+    interruptHandler env form _ = do
       outputStrLn "Interrupted with CTRL+C\n\
                   \You can use the !exit command or CTRL+D to exit"
-      loop env decode
+      loop env form
 
-    processInput :: Env -> String -> Bool -> IO Env
-    processInput env input decode = do
+    processInput :: Env -> String -> EvaluatedForm -> IO Env
+    processInput env input form = do
       let asts   = parseTricu input
           newEnv = evalTricu env asts
       case Map.lookup "!result" newEnv of
         Just r -> do
-          putStrLn $ "tricu > " ++ 
-            if decode 
-              then decodeResult r
-              else show r
+          putStrLn $ "tricu > " ++ formatResult form r
         Nothing -> pure ()
       return newEnv
-    
+
     errorHandler :: Env -> SomeException -> IO (Env)
     errorHandler env e = do
       putStrLn $ "Error: " ++ show e
       return env
-    
+
     strip :: String -> String
     strip = dropWhileEnd isSpace . dropWhile isSpace
+
+    handleSave :: Env -> EvaluatedForm -> InputT IO ()
+    handleSave env form = do
+      let fset = setComplete completeFilename defaultSettings
+      path <- runInputT fset $
+        getInputLineWithInitial "File to save < " ("", "")
+
+      case path of
+        Nothing -> do
+          outputStrLn "Save cancelled"
+          loop env form
+        Just p -> do
+          let definitions = Map.toList $ Map.delete "!result" env
+              filepath = strip p
+
+          outputStrLn "Starting save..."
+          liftIO $ writeFile filepath ""
+          outputStrLn "File created..."
+          forM_ definitions $ \(name, value) -> do
+            let content = name ++ " = " ++ formatResult TreeCalculus value ++ "\n"
+            outputStrLn $ "Writing definition: " ++ name ++ " with length " ++ show (length content)
+            liftIO $ appendFile filepath content
+          outputStrLn $ "Saved " ++ show (length definitions) ++ " definitions to " ++ p
+
+          loop env form

src/Research.hs

@@ -1,6 +1,5 @@
 module Research where
 
-import Control.Monad.State
 import Data.List                 (intercalate)
 import Data.Map                  (Map)
 import Data.Text                 (Text, replace)
@@ -53,17 +52,26 @@ data EvaluatedForm = TreeCalculus | FSL | AST | Ternary | Ascii | Decode
   deriving (Show, Data, Typeable)
 
 -- Environment containing previously evaluated TC terms
-type Env = Map.Map String T 
+type Env = Map.Map String T
 
--- Tree Calculus Reduction
+-- Tree Calculus Reduction Rules
+{- 
+  The t operator is left associative.
+  1.  t  t      a b       -> a
+  2.  t (t a)   b c       -> a c (b c)
+  3a. t (t a b) c t       -> a
+  3b. t (t a b) c (t u)   -> b u
+  3c. t (t a b) c (t u v) -> c u v
+-}
 apply :: T -> T -> T
-apply Leaf b                            = Stem b
-apply (Stem a) b                        = Fork a b
-apply (Fork Leaf a) _                   = a
-apply (Fork (Stem a1) a2) b             = apply (apply a1 b) (apply a2 b)
-apply (Fork (Fork a1 a2) a3) Leaf       = a1
-apply (Fork (Fork a1 a2) a3) (Stem u)   = apply a2 u
-apply (Fork (Fork a1 a2) a3) (Fork u v) = apply (apply a3 u) v
+apply (Fork Leaf a)         _         = a
+apply (Fork (Stem a) b) c             = apply (apply a c) (apply b c)
+apply (Fork (Fork a  b) c)  Leaf      = a
+apply (Fork (Fork a  b) c) (Stem u)   = apply b u
+apply (Fork (Fork a  b) c) (Fork u v) = apply (apply c u) v
+-- Left associative `t`
+apply  Leaf b                         = Stem b
+apply (Stem a) b                      = Fork a b
 
 -- Booleans
 _false :: T
@@ -77,7 +85,7 @@ _not = Fork (Fork _true (Fork Leaf _false)) Leaf
 
 -- Marshalling
 ofString :: String -> T
-ofString str = ofList (map ofNumber (map fromEnum str))
+ofString str = ofList $ map (ofNumber . fromEnum) str
 
 ofNumber :: Int -> T
 ofNumber 0 = Leaf
@@ -87,8 +95,7 @@ ofNumber n =
     (ofNumber (n `div` 2))
 
 ofList :: [T] -> T
-ofList [] = Leaf
-ofList (x:xs) = Fork x (ofList xs)
+ofList = foldr Fork Leaf
 
 toNumber :: T -> Either String Int
 toNumber Leaf = Right 0
@@ -122,11 +129,11 @@ formatResult Ascii        = toAscii
 formatResult Decode       = decodeResult
 
 toSimpleT :: String -> String
-toSimpleT s = T.unpack 
+toSimpleT s = T.unpack
   $ replace "Fork" "t"
   $ replace "Stem" "t"
   $ replace "Leaf" "t"
-  $ (T.pack s)
+  $ T.pack s
 
 toTernaryString :: T -> String
 toTernaryString Leaf = "0"
@@ -153,8 +160,18 @@ toAscii tree = go tree "" True
         ++ go right (prefix ++ (if isLast then "    " else "|   ")) True
 
 decodeResult :: T -> String
-decodeResult tc
-  | Right num  <- toNumber tc = show num
-  | Right str  <- toString tc = "\"" ++ str ++ "\""
-  | Right list <- toList tc   = "[" ++ intercalate ", " (map decodeResult list) ++ "]"
-  | otherwise                 = formatResult TreeCalculus tc
+decodeResult Leaf = "t"
+decodeResult tc =
+  case (toString tc, toList tc, toNumber tc) of
+    (Right s, _, _) | all isCommonChar s -> "\"" ++ s ++ "\""
+    (_, _, Right n) -> show n
+    (_, Right xs@(_:_), _) -> "[" ++ intercalate ", " (map decodeResult xs) ++ "]"
+    (_, Right [], _) -> "[]"
+    _ -> formatResult TreeCalculus tc
+  where
+    isCommonChar c =
+      let n = fromEnum c
+      in (n >= 32 && n <= 126)
+         || n == 9
+         || n == 10
+         || n == 13

test/Spec.hs

@@ -30,10 +30,11 @@ tests = testGroup "Tricu Tests"
   , parser
   , simpleEvaluation
   , lambdas
-  , baseLibrary
+  , providedLibraries
   , fileEval
   , modules
   , demos
+  , decoding
   ]
 
 lexer :: TestTree
@@ -329,151 +330,119 @@ lambdas = testGroup "Lambda Evaluation Tests"
         let input = "f = (\\x : (\\y : x y))\ng = (\\z : z)\nf g t"
         runTricu input @?= "Leaf"
 
-  , testCase "Lambda with a string literal" $ do
+  , testCase "Lambda applied to string literal" $ do
         let input = "f = (\\x : x)\nf \"hello\""
         runTricu input @?= "Fork (Fork Leaf (Fork Leaf (Fork Leaf (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) Leaf))))))) (Fork (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork Leaf (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) Leaf))))))) (Fork (Fork Leaf (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) Leaf))))))) (Fork (Fork Leaf (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) Leaf))))))) (Fork (Fork (Stem Leaf) (Fork (Stem Leaf) (Fork (Stem Leaf) (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork (Stem Leaf) Leaf))))))) Leaf))))"
 
 
-   , testCase "Lambda with an integer literal" $ do
+   , testCase "Lambda applied to integer literal" $ do
         let input = "f = (\\x : x)\nf 42"
         runTricu input @?= "Fork Leaf (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) (Fork Leaf (Fork (Stem Leaf) Leaf)))))"
 
-   , testCase "Lambda with a list literal" $ do
+   , testCase "Lambda applied to list literal" $ do
         let input = "f = (\\x : x)\nf [t (t t)]"
         runTricu input @?= "Fork Leaf (Fork (Stem Leaf) Leaf)"
+
+  , testCase "Lambda containing list literal" $ do
+      let input = "(\\a : [(a)]) 1"
+      runTricu input @?= "Fork (Fork (Stem Leaf) Leaf) Leaf"
   ]
 
-baseLibrary :: TestTree
-baseLibrary = testGroup "Library Tests"
-  [ testCase "K combinator 1" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "k (t) (t t)"
-          env = evalTricu library (parseTricu input)
-      result env @?= Leaf
-
-  , testCase "K combinator 2" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "k (t t) (t)"
-          env = evalTricu library (parseTricu input)
-      result env @?= Stem Leaf
-
-  , testCase "K combinator 3" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "k (t t t) (t)"
-          env = evalTricu library (parseTricu input)
-      result env @?= Fork Leaf Leaf
-
-  , testCase "S combinator" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "s (t) (t) (t)"
-          env = evalTricu library (parseTricu input)
-      result env @?= Fork Leaf (Stem Leaf)
-
-  , testCase "SKK == I (fully expanded)" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "s k k"
-          env = evalTricu library (parseTricu input)
-      result env @?= Fork (Stem (Stem Leaf)) (Stem Leaf)
-
-  , testCase "I combinator" $ do
-      library <- evaluateFile "./lib/base.tri"
-      let input = "i not?"
-          env = evalTricu library (parseTricu input)
-      result env @?= Fork (Fork (Stem Leaf) (Fork Leaf Leaf)) (Fork Leaf (Fork Leaf Leaf))
-
-  , testCase "Triage test Leaf" $ do
-      library <- evaluateFile "./lib/base.tri"
+providedLibraries :: TestTree
+providedLibraries = testGroup "Library Tests"
+  [ testCase "Triage test Leaf" $ do
+      library <- evaluateFile "./lib/list.tri"
       let input = "test t"
           env = decodeResult $ result $ evalTricu library (parseTricu input)
       env @?= "\"Leaf\""
 
   , testCase "Triage test (Stem Leaf)" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "test (t t)"
           env = decodeResult $ result $ evalTricu library (parseTricu input)
       env @?= "\"Stem\""
 
   , testCase "Triage test (Fork Leaf Leaf)" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "test (t t t)"
           env = decodeResult $ result $ evalTricu library (parseTricu input)
       env @?= "\"Fork\""
 
   , testCase "Boolean NOT: true" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "not? true"
           env = result $ evalTricu library (parseTricu input)
       env @?= Leaf
 
   , testCase "Boolean NOT: false" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "not? false"
           env = result $ evalTricu library (parseTricu input)
       env @?= Stem Leaf
 
 
   , testCase "Boolean AND TF" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "and? (t t) (t)"
           env = evalTricu library (parseTricu input)
       result env @?= Leaf
 
   , testCase "Boolean AND FT" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "and? (t) (t t)"
           env = evalTricu library (parseTricu input)
       result env @?= Leaf
 
   , testCase "Boolean AND FF" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "and? (t) (t)"
           env = evalTricu library (parseTricu input)
       result env @?= Leaf
 
   , testCase "Boolean AND TT" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "and? (t t) (t t)"
           env = evalTricu library (parseTricu input)
       result env @?= Stem Leaf
 
   , testCase "List head" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "head [(t) (t t) (t t t)]"
           env = evalTricu library (parseTricu input)
       result env @?= Leaf
 
   , testCase "List tail" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "head (tail (tail [(t) (t t) (t t t)]))"
           env = evalTricu library (parseTricu input)
       result env @?= Fork Leaf Leaf
 
   , testCase "List map" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "head (tail (map (\\a : (t t t)) [(t) (t) (t)]))"
           env = evalTricu library (parseTricu input)
       result env @?= Fork Leaf Leaf
 
   , testCase "Empty list check" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "emptyList? []"
           env = evalTricu library (parseTricu input)
       result env @?= Stem Leaf
 
   , testCase "Non-empty list check" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "not? (emptyList? [(1) (2) (3)])"
           env = evalTricu library (parseTricu input)
       result env @?= Stem Leaf
 
   , testCase "Concatenate strings" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "append \"Hello, \" \"world!\""
           env = decodeResult $ result $ evalTricu library (parseTricu input)
       env @?= "\"Hello, world!\""
 
   , testCase "Verifying Equality" $ do
-      library <- evaluateFile "./lib/base.tri"
+      library <- evaluateFile "./lib/list.tri"
       let input = "equal? (t t t) (t t t)"
           env = evalTricu library (parseTricu input)
       result env @?= Stem Leaf
@@ -490,12 +459,12 @@ fileEval = testGroup "File evaluation tests"
       res @?= Fork (Stem Leaf) Leaf
 
   , testCase "Mapping and Equality" $ do
-      library <- liftIO $ evaluateFile "./lib/base.tri"
+      library <- liftIO $ evaluateFile "./lib/list.tri"
       fEnv    <- liftIO $ evaluateFileWithContext library "./test/map.tri"
       (mainResult fEnv) @?= Stem Leaf
 
   , testCase "Eval and decoding string" $ do
-      library <- liftIO $ evaluateFile "./lib/base.tri"
+      library <- liftIO $ evaluateFile "./lib/list.tri"
       res <- liftIO $ evaluateFileWithContext library "./test/string.tri"
       decodeResult (result res) @?= "\"String test!\""
   ]
@@ -554,3 +523,35 @@ demos = testGroup "Test provided demo functionality"
       res     <- liftIO $ evaluateFileResult "./demos/levelOrderTraversal.tri"
       decodeResult res @?= "\"\n1 \n2 3 \n4 5 6 7 \n8 11 10 9 12 \""
   ]
+
+decoding :: TestTree
+decoding = testGroup "Decoding Tests"
+  [ testCase "Decode Leaf" $ do
+      decodeResult Leaf @?= "t"
+
+  , testCase "Decode list of non-ASCII numbers" $ do
+      let input = ofList [ofNumber 1, ofNumber 14, ofNumber 6]
+      decodeResult input @?= "[1, 14, 6]"
+
+  , testCase "Decode list of ASCII numbers as a string" $ do
+      let input = ofList [ofNumber 97, ofNumber 98, ofNumber 99]
+      decodeResult input @?= "\"abc\""
+
+  , testCase "Decode small number" $ do
+      decodeResult (ofNumber 42) @?= "42"
+
+  , testCase "Decode large number" $ do
+      decodeResult (ofNumber 9999) @?= "9999"
+
+  , testCase "Decode string in list" $ do
+      let input = ofList [ofString "hello", ofString "world"]
+      decodeResult input @?= "[\"hello\", \"world\"]"
+
+  , testCase "Decode mixed list with strings" $ do
+      let input = ofList [ofString "hello", ofNumber 42, ofString "world"]
+      decodeResult input @?= "[\"hello\", 42, \"world\"]"
+
+  , testCase "Decode nested lists with strings" $ do
+      let input = ofList [ofList [ofString "nested"], ofString "string"]
+      decodeResult input @?= "[[\"nested\"], \"string\"]"
+  ]

test/cycle-1.tri

@@ -1,4 +1,4 @@
 
-!import "test/cycle-2.tri" Cycle2
+!import "cycle-2.tri" Cycle2
 
 cycle1 = t Cycle2.cycle2

test/cycle-2.tri

@@ -1,4 +1,4 @@
 
-!import "test/cycle-1.tri" Cycle1
+!import "cycle-1.tri" Cycle1
 
 cycle2 = t Cycle1.cycle1

test/local-ns/1.tri

@@ -1,4 +1,4 @@
 
-!import "test/local-ns/2.tri" Two
+!import "2.tri" Two
 
 main = Two.x

test/local-ns/2.tri

@@ -1,2 +1,2 @@
 
-!import "test/local-ns/3.tri" !Local
+!import "3.tri" !Local

test/local-ns/3.tri

@@ -1,2 +1 @@
-
 x = 3

test/multi-level-A.tri

@@ -1,2 +1,2 @@
-!import "./test/multi-level-B.tri" B
+!import "multi-level-B.tri" B
 main = B.main

test/multi-level-B.tri

@@ -1,2 +1,2 @@
-!import "./test/multi-level-C.tri" C
+!import "multi-level-C.tri" C
 main = C.val

test/namespace-A.tri

@@ -1,2 +1,2 @@
-!import "./test/namespace-B.tri" B
+!import "namespace-B.tri" B
 main = B.x

test/vars-A.tri

@@ -1,6 +1,6 @@
 
-!import "./test/vars-B.tri" B
+!import "vars-B.tri" B
 
-!import "./test/vars-C.tri" C
+!import "vars-C.tri" C
 
 main = B.y (C.z)

tricu.cabal

@@ -1,7 +1,7 @@
 cabal-version: 1.12
 
 name:           tricu
-version:        0.13.0
+version:        0.18.1
 description:    A micro-language for exploring Tree Calculus
 author:         James Eversole
 maintainer:     james@eversole.co
@@ -27,10 +27,12 @@ executable tricu
     , cmdargs
     , containers
     , exceptions
+    , filepath
     , haskeline
     , megaparsec
     , mtl
     , text
+    , transformers
   other-modules:
     Eval
     FileEval
@@ -54,6 +56,7 @@ test-suite tricu-tests
     , cmdargs
     , containers
     , exceptions
+    , filepath
     , haskeline
     , megaparsec
     , mtl
@@ -61,6 +64,7 @@ test-suite tricu-tests
     , tasty-hunit
     , tasty-quickcheck
     , text
+    , transformers
   default-language:    Haskell2010
   other-modules:
     Eval