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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
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