implementation module parse
+import GenPrint
import StdString
import StdTuple
import StdList
import Data.Either
import Data.Maybe
import Data.Functor
+import Data.Tuple
import Control.Monad
import Control.Applicative
import Data.Func
+import StdMisc
from Data.List import intercalate, replicate, instance Functor []
from Text import class Text(concat), instance Text String
-import GenPrint
import yard
import lex
import AST
-parser :: LexerOutput -> ParserOutput
-parser (Left e) = Left e
-parser (Right r) = fst $ runParser parseProgram r
+parser :: [Token] -> ParserOutput
+parser ts = case runParser parseProgram ts of
+ (Right ast, [(p, t):xs]) = Left $ PositionalError p.line p.col (
+ "Unable to parse from: " +++ printToString t)
+ x = fst x
parseProgram :: Parser Token AST
-parseProgram = liftM2 AST (many parseVarDecl) (some parseFunDecl)
+parseProgram = many parseLetDecl >>= \fds1->
+ some parseFunDecl >>= \fds2->
+ pure $ AST (fds1++fds2)
+
+parseLetDecl :: Parser Token FunDecl
+parseLetDecl = peekPos >>= \p->
+ satTok LetToken >>|
+ parseFunType >>= \mt->
+ parseIdent >>= \f->
+ satTok AssignmentToken >>|
+ parseExpr >>= \e->
+ satTok SColonToken >>|
+ pure (FunDecl p f [] (Just mt) [] [ReturnStmt $ Just e])
parseFunDecl :: Parser Token FunDecl
-parseFunDecl = liftM5 FunDecl
- (parseIdent <* satTok BraceOpenToken)
- (parseSepList CommaToken parseIdent <* satTok BraceCloseToken)
- (optional parseFunType <* satTok CBraceOpenToken)
- (many parseVarDecl)
- (many parseStmt <* satTok CBraceCloseToken)
-
-parseStmt :: Parser Token Stmt
-parseStmt = parseIfStmt <|> parseWhileStmt <|>
+parseFunDecl = liftM6 FunDecl
+ (peekPos)
+ (parseIdent)
+ (parseBBraces $ parseSepList CommaToken parseIdent)
+ (optional (satTok DoubleColonToken *> parseFunType))
+ (satTok CBraceOpenToken *> many parseVarDecl)
+ (flatten <$> (many parseStmt <* satTok CBraceCloseToken))
+
+parseStmt :: Parser Token [Stmt]
+parseStmt = (parseIfStmt <|> parseWhileStmt <|>
parseSColon parseAssStmt <|> parseSColon parseReturnStmt <|>
- (liftM FunStmt (parseSColon parseFunCall))
+ (parseSColon parseFunCall
+ >>= \(ident, args, fs)->pure $ FunStmt ident args fs))
+ >>= \stmt->case stmt of
+ FunStmt "print" args fs = pure $ map (\a->FunStmt "print" [a] []) args
+ s = pure [s]
where
parseSColon :: (Parser Token a) -> Parser Token a
parseSColon p = p <* satTok SColonToken
(optional (satTok ElseToken *> (parseBlock<|> parseOneLine))))
parseWhileStmt :: Parser Token Stmt
- parseWhileStmt = satTok WhileToken *>
- (WhileStmt <$> (parseBBraces parseExpr) <*> parseBlock)
+ parseWhileStmt = satTok WhileToken *> (WhileStmt <$>
+ (parseBBraces parseExpr) <*> (parseBlock <|> parseOneLine))
parseBlock :: Parser Token [Stmt]
- parseBlock = parseBCBraces (many parseStmt)
+ parseBlock = parseBCBraces (flatten <$> many parseStmt)
parseOneLine :: Parser Token [Stmt]
- //first pure makes singleton list from the statement
- parseOneLine = pure <$> parseStmt
+ parseOneLine = parseStmt
-parseFunType :: Parser Token FunType
-parseFunType = satTok DoubleColonToken *>
- (parseInOutType <|> ((FunType []) <$> parseVoidOrType))
+parseFunType :: Parser Token Type
+parseFunType = parseFT >>= \t -> case t of
+ t1 ->> t2 = pure t
+ simpleT = pure $ FuncType simpleT
where
- parseInOutType :: Parser Token FunType
- parseInOutType = FunType <$> (some parseType <* satTok ArrowToken) <*> parseVoidOrType
-
- parseVoidOrType :: Parser Token (Maybe Type)
- parseVoidOrType = (satTok VoidToken *> pure Nothing) <|>
- (Just <$> parseType) <|> pure Nothing
+ parseFT :: Parser Token Type
+ parseFT = (liftM2 (->>) (parseSF <* satTok ArrowToken) (parseFT)) <|>
+ parseSF
+ parseSF :: Parser Token Type
+ parseSF = parseBBraces parseFT <|> parseType
parseVarDecl :: Parser Token VarDecl
-parseVarDecl = liftM3 VarDecl
- (parseType <|> trans1 VarToken VarType )
+parseVarDecl = liftM4 VarDecl
+ peekPos
+ ((parseType >>= \t->pure $ Just t)<|> trans1 VarToken Nothing)
(parseIdent <* satTok AssignmentToken)
(parseExpr <* satTok SColonToken)
trans1 IntTypeToken IntType <|>
trans1 CharTypeToken CharType <|>
trans1 BoolTypeToken BoolType <|>
+ trans1 VoidToken VoidType <|>
(ListType <$> (parseBSqBraces parseType)) <|>
(TupleType <$> (parseTuple parseType)) <|>
(IdType <$> parseIdent)
parseExpr :: Parser Token Expr
-parseExpr = //Operators in order of binding strength
+parseExpr = parseValueExpr <|> parseLambda
+
+parseValueExpr :: Parser Token Expr
+parseValueExpr = //Operators in order of binding strength
parseOpR (trans1 ColonToken BiCons) $
parseOpR (trans1 PipesToken BiOr) $
parseOpR (trans1 AmpersandsToken BiAnd) $
trans1 PercentToken BiMod) $ parseBasicExpr
where
parseOpR :: (Parser Token Op2) (Parser Token Expr) -> Parser Token Expr
- parseOpR ops prev = prev >>= \e1->optional (
+ parseOpR ops prev = peekPos >>= \pos-> prev >>= \e1->optional (
ops >>= \op->parseOpR ops prev >>= \e->pure (op, e)
- ) >>= \moe->pure $ maybe e1 (\(op,e2)->Op2Expr e1 op e2) moe
+ ) >>= \moe->pure $ maybe e1 (\(op,e2)->Op2Expr pos e1 op e2) moe
parseOpL :: (Parser Token Op2) (Parser Token Expr) -> Parser Token Expr
- parseOpL ops prev = prev >>= \e1->many (
- ops >>= \op->prev >>= \e->pure (op, e)
- ) >>= \moe->foldM (\e->(\(op,e2)->pure $ Op2Expr e op e2)) e1 moe
+ parseOpL ops prev = peekPos >>= \pos-> prev >>= \e1->many (
+ ops >>= \op->prev >>= \e->pure (op, e))
+ >>= \moe->foldM (\e->(\(op,e2)->pure $ Op2Expr pos e op e2)) e1 moe
parseBasicExpr :: Parser Token Expr
- parseBasicExpr =
- (TupleExpr <$> (parseTuple parseExpr)) <|>
- (FunExpr <$> parseFunCall) <|>
+ parseBasicExpr = peekPos >>= \pos ->
+ (trans2 (StringToken []) (\(StringToken cs)->makeStrExpr pos cs)) <|>
+ (TupleExpr pos <$> (parseTuple parseExpr)) <|>
parseBBraces parseExpr <|>
- trans1 EmptyListToken EmptyListExpr <|>
- trans1 TrueToken (BoolExpr True) <|>
- trans1 FalseToken (BoolExpr False) <|>
- trans2 (NumberToken zero) (\(NumberToken i)->IntExpr i) <|>
- trans2 (CharToken zero) (\(CharToken c)->CharExpr c) <|>
- (Op1Expr <$> parseOp1 <*> parseExpr) <|>
- (VarExpr <$> parseVarDef)
-
-parseFunCall :: Parser Token FunCall
-parseFunCall = FunCall <$> parseIdent <*> (parseBBraces $ parseSepList CommaToken parseExpr)
+ parseListLiteral <|>
+ trans1 EmptyListToken (EmptyListExpr pos) <|>
+ trans1 TrueToken (BoolExpr pos True) <|>
+ trans1 FalseToken (BoolExpr pos False) <|>
+ trans2 (NumberToken zero) (\(NumberToken i)->IntExpr pos i) <|>
+ trans2 (CharToken zero) (\(CharToken c)->CharExpr pos c) <|>
+ (Op1Expr pos <$> parseOp1 <*> parseExpr) <|>
+ (parseFunCall >>= \(ident, args, fs)->
+ pure $ FunExpr pos ident args fs) <|>
+ (VarExpr pos <$> parseVarDef)
+
+ parseListLiteral :: Parser Token Expr
+ parseListLiteral = peekPos >>= \p->
+ satTok SquareOpenToken >>|
+ many (parseExpr <* satTok CommaToken) >>= \es->
+ parseExpr >>= \e->
+ foldM (\res e-> pure $ Op2Expr p e BiCons res)
+ (EmptyListExpr p)
+ [e : reverse es] >>= \res->
+ satTok SquareCloseToken >>|
+ pure res
+
+parseLambda :: Parser Token Expr
+parseLambda = LambdaExpr <$> peekPos
+ <*> (satTok BackslashToken *> many parseIdent)
+ <*> (satTok ArrowToken *> parseExpr)
+
+makeStrExpr :: Pos [Char] -> Expr
+makeStrExpr p [] = EmptyListExpr p
+makeStrExpr p [x:xs] = Op2Expr p (CharExpr zero x) BiCons (makeStrExpr p xs)
+
+parseFunCall :: Parser Token (String, [Expr], [FieldSelector])
+parseFunCall = liftM3 (\x y z->(x, y, z))
+ parseIdent
+ (parseBBraces $ parseSepList CommaToken parseExpr)
+ parseFieldSelectors
parseVarDef :: Parser Token VarDef
-parseVarDef = liftM2 VarDef
- parseIdent
- (many (satTok DotToken *> (
- (parseIdent >>= (\i.if (i == "hd") (pure FieldHd) empty)) <|>
- (parseIdent >>= \i.if (i == "tl") (pure FieldTl) empty) <|>
- (parseIdent >>= \i.if (i == "fst") (pure FieldFst) empty) <|>
- (parseIdent >>= \i.if (i == "snd") (pure FieldSnd) empty))))
+parseVarDef = liftM2 VarDef parseIdent parseFieldSelectors
+
+parseFieldSelectors :: Parser Token [FieldSelector]
+parseFieldSelectors = many (satTok DotToken *>
+ parseIdent >>= \i->case i of
+ "hd" = pure FieldHd
+ "tl" = pure FieldTl
+ "fst" = pure FieldFst
+ "snd" = pure FieldSnd
+ _ = empty)
parseOp1 :: Parser Token Op1
parseOp1 = trans1 DashToken UnMinus <|> trans1 ExclamationToken UnNegation
parseTuple :: (Parser Token a) -> Parser Token (a, a)
parseTuple p = satTok BraceOpenToken *>
- (liftM2 (\a->(\b->(a,b))) (p <* satTok CommaToken) p)
+ (liftM2 tuple (p <* satTok CommaToken) p)
<* satTok BraceCloseToken
+trans :: TokenValue (TokenValue -> a) -> Parser Token (Pos, a)
+trans t f = (\(pos,token)->(pos, f token)) <$> satTok t
+
trans2 :: TokenValue (TokenValue -> a) -> Parser Token a
-trans2 t f = (\(_,token)->f token) <$> satTok t
+trans2 t f = snd <$> trans t f
trans1 :: TokenValue a -> Parser Token a
trans1 t r = trans2 t $ const r
+peekPos :: Parser Token Pos
+peekPos = fst <$> peek
+
derive gPrint TokenValue
derive gEq TokenValue
satTok :: TokenValue -> Parser Token Token
-satTok t = top >>= \tok=:({line,col},token) -> if (eq t token)
+satTok t = top >>= \tok=:({line,col},token) -> if (tokEq t token)
(pure tok) (fail <?> PositionalError line col
- ("ParseError: Unexpected token: " +++ printToString token))
- where
- eq (IdentToken _) (IdentToken _) = True
- eq (NumberToken _) (NumberToken _) = True
- eq (CharToken _) (CharToken _) = True
- eq x y = gEq {|*|} x y
+ ("ParseError: Unexpected token: " +++ printToString token
+ +++ "\nExpected: " +++ printToString t))
+
+tokEq (IdentToken _) (IdentToken _) = True
+tokEq (NumberToken _) (NumberToken _) = True
+tokEq (CharToken _) (CharToken _) = True
+tokEq (StringToken _) (StringToken _) = True
+tokEq x y = gEq {|*|} x y
parseSepList :: TokenValue (Parser Token a) -> Parser Token [a]
-parseSepList sep p =
- (liftM2 (\es->(\e->reverse [e:es])) (some (p <* satTok sep)) p) <|>
- (liftM pure p) <|> pure empty
+parseSepList sep p = pSL` sep p <|> pure []
+ where
+ pSL` sep p = (p <* satTok sep >>= \v1->parseSepList sep p >>= \vs->pure [v1:vs]) <|> (p >>= \v->pure [v])
parseIdent :: Parser Token String
-parseIdent = trans2 (IdentToken "") (\(IdentToken e).toString e)
+parseIdent = trans2 (IdentToken "") (\(IdentToken e)->toString e)
+
+//liftM only goes to liftM5
+liftM6 f m1 m2 m3 m4 m5 m6 = f <$> m1 <*> m2 <*> m3 <*> m4 <*> m5 <*> m6
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