load a prelude

app/Builtins.hs

@@ -1,5 +1,7 @@
 module Builtins where
 
+import Paths_prlg
+
 import Code (Builtin(..), Code, Datum(..), Instr(..), InterpFn)
 import CodeLens
 import qualified Compiler as Co
@@ -329,6 +331,17 @@ addBi b n a =
   addProc [[U (LocalRef $ r - 1) | r <- [1 .. a]] ++ [Invoke $ bi b]] n a
 
 {- loading code -}
+doLoad :: Bool -> String -> InterpFn
+doLoad queryMode fn = do
+  src' <- liftIO $ catch (Right <$> readFile fn) (pure . Left)
+  case src' of
+    Right src -> do
+      res <- runExceptT $ processInput fn queryMode src
+      case res of
+        Right _ -> continue
+        Left e -> prlgError $ "loading from '" ++ fn ++ "': " ++ e
+    Left e -> prlgError $ show (e :: IOException)
+
 load :: Bool -> InterpFn
 load queryMode =
   withArgs [0] $ \[arg] -> do
@@ -337,14 +350,7 @@ load queryMode =
     case derefHeap heap arg of
       BoundRef _ (Atom a) -> do
         let fn = itos M.! a
-        src' <- liftIO $ catch (Right <$> readFile fn) (pure . Left)
+        doLoad queryMode (itos M.! a)
-        case src' of
-          Right src -> do
-            res <- runExceptT $ processInput fn queryMode src
-            case res of
-              Right _ -> continue
-              Left e -> prlgError $ "loading from '" ++ fn ++ "': " ++ e
-          Left e -> prlgError $ show (e :: IOException)
       _ -> prlgError "load needs an atom"
 
 {- actual prlgude -}
@@ -426,3 +432,7 @@ addPrelude = do
   addBi nl "nl" 0
   {- debug -}
   addBi (use id >>= liftIO . print >> pure Nothing) "interpreter_trace" 0
+  {- load the prelude file -}
+  preludeFile <- liftIO $ getDataFileName "prelude.pl"
+  doLoad False preludeFile
+  pure ()

inst/prelude.pl

@@ -0,0 +1,5 @@
+member(X, [X|_]).
+member(X, [_|T]) :- member(X,T).
+
+append([], X, X).
+append([X|T], Y, [X|TY]) :- append(T,Y,TY).

prlg.cabal

@@ -21,11 +21,14 @@ maintainer:         exa.exa@gmail.com
 -- category:
 extra-source-files: CHANGELOG.md
 
+data-dir:       inst
+data-files:     *.pl
+
 executable prlg
     main-is:          Main.hs
 
     -- Modules included in this executable, other than Main.
-    other-modules:    Interpreter, Compiler, Parser, Frontend, IR, Operators, Code, Builtins, Env, Load, CodeLens, Heap
+    other-modules:    Interpreter, Compiler, Parser, Frontend, IR, Operators, Code, Builtins, Env, Load, CodeLens, Heap, Paths_prlg
 
     -- LANGUAGE extensions used by modules in this package.
     -- other-extensions: