implementation module parse
import StdString
+import StdTuple
+import StdList
+from StdFunc import const, o
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
-parse :: LexerOutput -> ParserOutput
-parse (Left e) = Left ("Lexer error: " +++ e)
-parse (Right r) = Left "Parser not yet implemented"
+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 = AST <$> some parseFunDecl
+
+parseFunDecl :: Parser Token FunDecl
+parseFunDecl = liftM6 FunDecl
+ (peekPos)
+ (parseIdent)
+ (parseBBraces $ parseSepList CommaToken parseIdent)
+ (optional parseFunType)
+ (satTok CBraceOpenToken *> many parseVarDecl)
+ (many parseStmt <* satTok CBraceCloseToken)
+
+parseStmt :: Parser Token Stmt
+parseStmt = parseIfStmt <|> parseWhileStmt <|>
+ parseSColon parseAssStmt <|> parseSColon parseReturnStmt <|>
+ (parseSColon parseFunCall
+ >>= \(ident, args, fs)->pure $ FunStmt ident args fs)
+ where
+ parseSColon :: (Parser Token a) -> Parser Token a
+ parseSColon p = p <* satTok SColonToken
+
+ parseReturnStmt :: Parser Token Stmt
+ parseReturnStmt =
+ satTok ReturnToken *> liftM ReturnStmt (optional parseExpr)
+
+ parseAssStmt :: Parser Token Stmt
+ parseAssStmt =
+ AssStmt <$> (parseVarDef <* satTok AssignmentToken) <*> parseExpr
+
+ parseIfStmt :: Parser Token Stmt
+ parseIfStmt = liftM3 IfStmt
+ (satTok IfToken *> parseBBraces parseExpr)
+ (parseBlock <|> parseOneLine)
+ (liftM (fromMaybe [])
+ (optional (satTok ElseToken *> (parseBlock<|> parseOneLine))))
+
+ parseWhileStmt :: Parser Token Stmt
+ parseWhileStmt = satTok WhileToken *> (WhileStmt <$>
+ (parseBBraces parseExpr) <*> (parseBlock <|> parseOneLine))
+
+ parseBlock :: Parser Token [Stmt]
+ parseBlock = parseBCBraces (many parseStmt)
+
+ parseOneLine :: Parser Token [Stmt]
+ parseOneLine = pure <$> parseStmt
+
+parseFunType :: Parser Token Type
+parseFunType = satTok DoubleColonToken *> parseFT
+ where
+ parseFT :: Parser Token Type
+ parseFT = (liftM2 (->>) (parseSF <* satTok ArrowToken) (parseFT)) <|>
+ parseSF
+ parseSF :: Parser Token Type
+ parseSF = parseBBraces parseFT <|> parseType
+
+parseVarDecl :: Parser Token VarDecl
+parseVarDecl = liftM4 VarDecl
+ peekPos
+ ((parseType >>= \t->pure $ Just t)<|> trans1 VarToken Nothing)
+ (parseIdent <* satTok AssignmentToken)
+ (parseExpr <* satTok SColonToken)
+
+parseType :: Parser Token Type
+parseType =
+ 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
+ parseOpR (trans1 ColonToken BiCons) $
+ parseOpR (trans1 PipesToken BiOr) $
+ parseOpR (trans1 AmpersandsToken BiAnd) $
+ parseOpR (trans1 EqualsToken BiEquals <|>
+ trans1 LesserToken BiLesser <|>
+ trans1 BiggerToken BiGreater <|>
+ trans1 LesserEqToken BiLesserEq <|>
+ trans1 GreaterEqToken BiGreaterEq <|>
+ trans1 NotEqualToken BiUnEqual) $
+ parseOpL (trans1 PlusToken BiPlus <|>
+ trans1 DashToken BiMinus) $
+ parseOpL (trans1 StarToken BiTimes <|>
+ trans1 SlashToken BiDivide <|>
+ trans1 PercentToken BiMod) $ parseBasicExpr
+ where
+ parseOpR :: (Parser Token Op2) (Parser Token Expr) -> Parser Token Expr
+ parseOpR ops prev = peekPos >>= \pos-> prev >>= \e1->optional (
+ ops >>= \op->parseOpR ops prev >>= \e->pure (op, e)
+ ) >>= \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 = 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 = peekPos >>= \pos ->
+ (TupleExpr pos <$> (parseTuple parseExpr)) <|>
+ parseBBraces parseExpr <|>
+ 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)
+
+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 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
+
+parseBBraces :: (Parser Token a) -> Parser Token a
+parseBBraces p = satTok BraceOpenToken *> p <* satTok BraceCloseToken
+
+parseBCBraces :: (Parser Token a) -> Parser Token a
+parseBCBraces p = satTok CBraceOpenToken *> p <* satTok CBraceCloseToken
+
+parseBSqBraces :: (Parser Token a) -> Parser Token a
+parseBSqBraces p = satTok SquareOpenToken *> p <* satTok SquareCloseToken
+
+parseTuple :: (Parser Token a) -> Parser Token (a, a)
+parseTuple p = satTok BraceOpenToken *>
+ (liftM2 tuple (p <* satTok CommaToken) p)
+ <* satTok BraceCloseToken
+
+trans :: TokenValue (TokenValue -> a) -> Parser Token (Pos, a)
+trans t f = (\(pos,token)->(pos, f token)) <$> satTok t
+
+trans2 :: TokenValue (TokenValue -> a) -> Parser Token a
+trans2 t f = snd <$> 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)
+ (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
+
+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
+
+parseIdent :: Parser Token String
+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
repositories / cc1516.git / blobdiff