NanoProlog 0.1 → 0.1.1

raw patch · 3 files changed

+60/−60 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• NanoProlog.cabal +2/−2
• src/Language/Prolog/NanoProlog/Main.hs +0/−58
• src/Main.hs +58/−0

@@ -1,5 +1,5 @@ Name:                NanoProlog-Version:             0.1+Version:             0.1.1 Synopsis:            Very small  interpreter for a Prolog-like language Description:         This package was developed to demonstrate the ideas behind                      the Prolog language. It contains a very small interpreter@@ -22,7 +22,7 @@  Executable nano-prolog   Hs-source-dirs: src-  Main-is: Language/Prolog/NanoProlog/Main.hs+  Main-is: Main.hs    Build-depends:     base >= 4 && < 5

@@ -1,58 +0,0 @@-{-# LANGUAGE Rank2Types #-}-{-# LANGUAGE FlexibleContexts #-}-{-# LANGUAGE TypeSynonymInstances #-}-{-# LANGUAGE FlexibleInstances #-}--module Language.Prolog.NanoProlog.Main where--import            Language.Prolog.NanoProlog.Lib-import            Text.ParserCombinators.UU-import            System.IO---- * Running the Interpreter--- ** The main interpreter--- | The `main` program prompt for a file with Prolog rules and call the main--- interpreter loop-main :: IO ()-main = do  hSetBuffering stdin LineBuffering-           putStr "File with rules? "-           fn  <- getLine-           s   <- readFile fn-           let (rules, errors) = startParse (pList pRule)  s-           if null errors then  do  mapM_ print rules-                                    loop rules-                          else  do  putStrLn "No rules parsed"-                                    mapM_ print errors-                                    main---- | `loop` ask for a goal, and enuartes all solutions found, each preceded by--- a trace conatining the rules applied in a tree-like fashion-loop :: [Rule] -> IO ()-loop rules = do  putStr "goal? "-                 s <- getLine-                 unless (s == "quit") $-                   do  let (goal, errors) = startParse pFun s-                       if null errors-                         then  printSolutions (solve rules emptyEnv 0 [goal])-                         else  do  putStrLn "Some goals were expected:"-                                   mapM_ print errors-                       loop rules---- | `printSolutions` takes the result of a treewalk, which constructs--- all the proofs, and pairs them with their final--- substitutions. Alternative approaches in printing are to print the--- raw proofs, i.e. without applying the final substitution (remove--- the @subst env@ ). This nicely shows how the intermediate variables--- come into life. By including the test on the length the facts--- directly stemming from the data base are not printed. This makes--- the proofs much shorter, but a bit less complete.-printSolutions ::  Result -> IO ()-printSolutions result = sequence_-  [  do  sequence_ [ putStrLn (prefix ++ " " ++  show (subst env pr))-                   | (prefix, pr@(p :<-: pp)) <- reverse proof---                 , length pp >0-                   ]-         putStr "substitution: "-         putStrLn (show' env)-         void getLine-  |  (proof, env) <- enumerateDepthFirst [] ["0"] result ]

@@ -0,0 +1,58 @@+{-# LANGUAGE Rank2Types #-}+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE TypeSynonymInstances #-}+{-# LANGUAGE FlexibleInstances #-}++module Main where++import            Language.Prolog.NanoProlog.Lib+import            Text.ParserCombinators.UU+import            System.IO++-- * Running the Interpreter+-- ** The main interpreter+-- | The `main` program prompt for a file with Prolog rules and call the main+-- interpreter loop+main :: IO ()+main = do  hSetBuffering stdin LineBuffering+           putStr "File with rules? "+           fn  <- getLine+           s   <- readFile fn+           let (rules, errors) = startParse (pList pRule)  s+           if null errors  then  do  mapM_ print rules+                                     loop rules+                           else  do  putStrLn "No rules parsed"+                                     mapM_ print errors+                                     main++-- | `loop` ask for a goal, and enuartes all solutions found, each preceded by+-- a trace conatining the rules applied in a tree-like fashion+loop :: [Rule] -> IO ()+loop rules = do  putStr "goal? "+                 s <- getLine+                 unless (s == "quit") $+                   do  let (goal, errors) = startParse pFun s+                       if null errors+                         then  printSolutions (solve rules emptyEnv 0 [goal])+                         else  do  putStrLn "Some goals were expected:"+                                   mapM_ print errors+                       loop rules++-- | `printSolutions` takes the result of a treewalk, which constructs+-- all the proofs, and pairs them with their final+-- substitutions. Alternative approaches in printing are to print the+-- raw proofs, i.e. without applying the final substitution (remove+-- the @subst env@ ). This nicely shows how the intermediate variables+-- come into life. By including the test on the length the facts+-- directly stemming from the data base are not printed. This makes+-- the proofs much shorter, but a bit less complete.+printSolutions ::  Result -> IO ()+printSolutions result = sequence_+  [  do  sequence_ [ putStrLn (prefix ++ " " ++  show (subst env pr))+                   | (prefix, pr@(p :<-: pp)) <- reverse proof+--                 , length pp >0+                   ]+         putStr "substitution: "+         putStrLn (show' env)+         void getLine+  |  (proof, env) <- enumerateDepthFirst [] ["0"] result ]