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authoraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
committeraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
commite9e80fc389365e24d4300d7d5390c7d833a96c50 (patch)
treef0b58473adaa670bd8fc52ada419d8cad470ee03 /src/Transfer/InterpreterAPI.hs
parentb96b36f43de3e2f8b58d5f539daa6f6d47f25870 (diff)
changed names of resource-1.3; added a note on homepage on release
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+module Transfer.InterpreterAPI (Env, builtin,
+ load, loadFile,
+ evaluateString, evaluateExp
+ ) where
+
+import Transfer.Core.Abs
+import Transfer.Core.Lex
+import Transfer.Core.Par
+import Transfer.Core.Print
+import Transfer.Interpreter
+import Transfer.ErrM
+
+-- | Read a transfer module in core format from a string.
+load :: Monad m =>
+ String -- ^ Input source name, for error messages.
+ -> String -- ^ Module contents.
+ -> m Env
+load n s = case pModule (myLexer s) of
+ Bad e -> fail $ "Parse error in " ++ n ++ ": " ++ e
+ Ok m -> return $ addModuleEnv builtin m
+
+-- | Read a transfer module in core format from a file.
+-- Fails in the IO monad if there is a problem loading the file.
+loadFile :: FilePath -> IO Env
+loadFile f = readFile f >>= load f
+
+-- | Read a transfer expression from a string and evaluate it.
+-- Returns the result as a string.
+evaluateString :: Monad m => Env -> String -> m String
+evaluateString env s =
+ case pExp (myLexer s) of
+ Bad e -> fail $ "Parse error: " ++ e
+ Ok e -> do
+ let v = eval env e
+ return $ printValue v
+
+-- | Evaluate an expression in the given environment.
+evaluateExp :: Env -> Exp -> Exp
+evaluateExp env exp = valueToExp $ eval env exp