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author | Ben Sima <ben@bsima.me> | 2019-11-02 15:33:13 -0700 |
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committer | Ben Sima <ben@bsima.me> | 2019-11-02 15:33:13 -0700 |
commit | 9d114cfc773171b0a95bd4d2c39f1bb0eb783c8d (patch) | |
tree | 20766a760ed0141cf39153565e8552f6739c632d /Com/Simatime/language/Bs/Expr.hs | |
parent | d2a37f5de160160eadbacd7b8dc2567f78a0543d (diff) |
rename everything back to caps to appease ghc
Diffstat (limited to 'Com/Simatime/language/Bs/Expr.hs')
-rw-r--r-- | Com/Simatime/language/Bs/Expr.hs | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/Com/Simatime/language/Bs/Expr.hs b/Com/Simatime/language/Bs/Expr.hs new file mode 100644 index 0000000..a39c7b6 --- /dev/null +++ b/Com/Simatime/language/Bs/Expr.hs @@ -0,0 +1,154 @@ +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE NoImplicitPrelude #-} +{-# LANGUAGE DeriveDataTypeable #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +module Language.Bs.Expr where + +import Data.String (String) +import Data.Text (Text) +import qualified Data.Text as T +import GHC.Show +import Protolude hiding (show) +import qualified Text.PrettyPrint.Leijen.Text as PP +import Text.PrettyPrint.Leijen.Text hiding ((<$>)) + +type Ctx = Map Text Expr +data Env = Env { env :: Ctx, fenv :: Ctx } + deriving (Eq) + +newtype Eval a = Eval { unEval :: ReaderT Env IO a } + deriving (Monad, Functor, Applicative, MonadReader Env, MonadIO) + +data IFunc = IFunc { fn :: [Expr] -> Eval Expr } + deriving (Typeable) + +instance Eq IFunc where + (==) _ _ = False + +data Expr + = Atom Text + | List [Expr] + | Numb Integer + | Tape Text + | IFun IFunc -- TODO: call this Kern + | Func IFunc Env + | Bool Bool + | Nil + deriving (Typeable, Eq) + +instance Show Expr where + show = T.unpack . ppexpr + +data LispErrorType + = NumArgs Integer [Expr] + | LengthOfList Text Int + | ExpectedList Text + | ParseError String + | TypeMismatch Text Expr + | BadSpecialForm Text + | NotFunction Expr + | UnboundVar Text + | Default Expr + | ReadFileError Text + deriving (Typeable) + +data LispError = LispError Expr LispErrorType + +instance Show LispErrorType where + show = T.unpack . ppexpr + +instance Show LispError where + show = T.unpack . ppexpr + +instance Exception LispErrorType +instance Exception LispError + +ppexpr :: Pretty a => a -> Text +ppexpr x = PP.displayTStrict (PP.renderPretty 1.0 70 (pretty x)) + +--prettyList :: [Doc] -> Doc +--prettyList = encloseSep lparen rparen PP.space + +instance Pretty Expr where + pretty v = + case v of + Atom a -> + textStrict a + + List ls -> + prettyList $ fmap pretty ls + + Numb n -> + integer n + + Tape t -> + textStrict "\"" <> textStrict t <> textStrict "\"" + + IFun _ -> + textStrict "<internal function>" + + Func _ _ -> + textStrict "<lambda function>" + + Bool True -> + textStrict "#t" + + Bool False -> + textStrict "#f" + + Nil -> + textStrict "'()" + +instance Pretty LispErrorType where + pretty err = case err of + NumArgs i args -> + textStrict "number of arguments" + <$$> textStrict "expected" + <+> textStrict (T.pack $ show i) + <$$> textStrict "received" + <+> textStrict (T.pack $ show $ length args) + + + LengthOfList txt i -> + textStrict "length of list in:" + <+> textStrict txt + <$$> textStrict "length:" + <+> textStrict (T.pack $ show i) + + ParseError txt -> + textStrict "cannot parse expr:" + <+> textStrict (T.pack txt) + + TypeMismatch txt expr -> + textStrict "type mismatch:" + <$$> textStrict txt + <$$> pretty expr + + BadSpecialForm txt -> + textStrict "bad special form:" + <$$> textStrict txt + + NotFunction expr -> + textStrict "not a function" + <$$> pretty expr + + UnboundVar txt -> + textStrict "unbound variable:" + <$$> textStrict txt + + Default _ -> + textStrict "default error" + + ReadFileError txt -> + textStrict "error reading file:" + <$$> textStrict txt + + ExpectedList txt -> + textStrict "expected list:" + <$$> textStrict txt + +instance Pretty LispError where + pretty (LispError expr typ) = + textStrict "error evaluating:" + <$$> indent 4 (pretty expr) + <$$> pretty typ |