Merge pull request #9 from sandrolovnicki/dev

dev + export-command

README.md

@@ -31,6 +31,7 @@ Inside `import/` directory, many useful λ-expressions are already implemented t
     - [Define](#def)
     - [Evaluate](#eval)
     - [Import](#imp)
+    - [Export](#exp)
     - [Comment](#comm)
     - [Run](#run)
     - [Print](#print)
@@ -190,6 +191,15 @@ A block of code in pLam is a line, and possible lines (commands) are the followi
 - example: `:import std`
 - restriction: `<string>.plam` has to be inside `import/` directory within the pLam project directory
 
+<a name="exp"/>
+
+### Export
+
+- syntax `:export <string<`
+- semantics: put all the expressions in the list of environment variables into the file `import/<string>.plam`
+- example: `:export test`
+- restriction: `<string>.plam` cannot already exist
+
 <a name="comm"/>
 
 ### Comment

app/Main.hs

@@ -6,14 +6,15 @@ import Reducer
 import Helper
 
 import Control.Monad.State
-import System.IO (hFlush, stdout)
+import System.IO (hFlush, stdout, hPutStrLn, hClose, openFile, IOMode(WriteMode))
 import Debug.Trace
 import System.Exit
 import System.Console.Haskeline
 import System.Environment
+import System.Directory (doesFileExist)
 
 
-version = "2.0.0"
+version = "2.1.0"
 heading = "\x1b[1;36m\
 \         _\n\
 \        | |\n\
@@ -93,7 +94,18 @@ execute line env =
                 Import f -> do
                     content <- liftIO $ readFile (importPath ++ f ++ ".plam")
                     let exprs = lines content
-                    execAll exprs env                  
+                    execAll exprs env
+                Export f -> do
+                    fileExists <- liftIO $ doesFileExist (importPath ++ f ++ ".plam")
+                    if not fileExists
+                        then do
+                            outFile <- liftIO $ openFile (importPath ++ f ++ ".plam") WriteMode
+                            liftIO $ mapM_ (saveGlobal outFile) (reverse env)
+                            liftIO $ hClose outFile
+                            outputStrLn("--- successfully exported to import/" ++ f ++ ".plam")
+                        else do
+                            outputStrLn("--- export failed : " ++ f ++ " already exists")
+                    return env
                 Review r -> do
                     case r of
                        "all" -> do
@@ -149,6 +161,13 @@ execJustProg (line:ls) env =
                         Right exp -> do
                             autoProgReduce env exp 0
                             execJustProg ls env'
+                Review r -> do
+                    case r of
+                       "all" -> do
+                           putStrLn " ENVIRONMENT:"
+                           mapM_ printGlobal env
+                       otherwise -> putStrLn ("--- definition of " ++ show r ++ ": " ++ reviewVariable env r)
+                    execJustProg ls env
                 Print s -> do
                     putStrLn s
                     execJustProg ls env

pLam.cabal

@@ -1,5 +1,5 @@
 name:                pLam
-version:             2.0.0
+version:             2.1.0
 -- synopsis:
 -- description:
 homepage:            https://github.com/sandrolovnicki/pLam#readme
@@ -32,6 +32,7 @@ executable plam
                      , mtl
                      , containers
                      , haskeline
+                     , directory
   default-language:    Haskell2010
 
 source-repository head

src/Helper.hs

@@ -5,7 +5,7 @@ import Reducer
 import Parser
 
 import Control.Monad.State
-import System.IO (hFlush, stdout)
+import System.IO (hFlush, stdout, Handle, hPutStrLn)
 import Debug.Trace
 import System.Console.Haskeline
 
@@ -14,6 +14,19 @@ import System.Console.Haskeline
 showGlobal :: (String, Expression) -> InputT IO ()
 showGlobal (n, e) = outputStrLn ("--- " ++ show n ++ " = " ++ show e)
 
+printGlobal :: (String, Expression) -> IO ()
+printGlobal (n, e) = putStrLn ("--- " ++ show n ++ " = " ++ show e)
+
+removeLambda :: String -> String
+removeLambda target =
+    let
+        repl 'λ' = '\\'
+        repl  c  =  c
+    in map repl target
+
+saveGlobal :: Handle -> (String, Expression) -> IO ()
+saveGlobal h (n, e) = hPutStrLn h (n ++ " = " ++ (removeLambda (show e)))
+
 convertToName :: Environment -> Expression -> String
 convertToName [] exp = findNumeral exp
 convertToName ((v,e):rest) ex 

src/Parser.hs

@@ -164,6 +164,13 @@ parseImport = do
     f <- filename
     return $ Import f
 
+parseExport :: Parser Command
+parseExport = do
+    reserved ":export"
+    spaces
+    f <- filename
+    return $ Export f
+
 parseReview :: Parser Command
 parseReview = do
     reserved ":review"
@@ -200,12 +207,14 @@ parseLine :: Parser Command
 parseLine =  try parseDefine
          <|> parseShowDetailed
          <|> parseImport
+         <|> parseExport
          <|> parseReview
          <|> parseRun
          <|> parsePrint
          <|> parseComment
          <|> parseShow
          <|> parseEmptyLine
+
 -------------------------------------------------------------------------------------
 
 -------------------------------------------------------------------------------------

src/Syntax.hs

@@ -43,6 +43,7 @@ data Command = Define String Expression
              | Show Expression
              | ShowDetailed Expression
              | Import String
+             | Export String
              | Review String
              | Comment String
              | Run String