src/parse.icl

   1 implementation module parse
   2
   3 import StdString
   4 import StdTuple
   5 import StdList
   6 from StdFunc import const
   7 import Data.Either
   8 import Data.Functor
   9 import Data.Maybe
  10 import Control.Monad
  11 import Control.Applicative
  12 import Data.Func
  13 from Text import class Text(concat), instance Text String
  14
  15 import yard
  16 import lex
  17
  18 parser :: LexerOutput -> ParserOutput
  19 parser (Left e) = Left $ toString $ LexError e
  20 parser (Right r) = case runParser parseProgram r of
  21         (Right p, _) = Right p
  22         (Left e, _) = Left $ toString e
  23
  24 parseProgram :: Parser Token AST
  25 parseProgram = parseVarDecl >>= \t.pure $ AST [t] []
  26
  27 parseVarDecl :: Parser Token VarDecl
  28 parseVarDecl =
  29         (parseType <|> trans1 VarToken VarType )
  30         >>= \t->parseIdent <* satTok AssignmentToken
  31         >>= \i->parseExpr <* satTok SColonToken
  32         >>= \e->pure $ VarDecl i t e
  33
  34 parseType :: Parser Token Type
  35 parseType =
  36         trans1 IntTypeToken IntType <|>
  37         trans1 CharTypeToken CharType <|>
  38         trans1 BoolTypeToken BoolType <|>
  39         (satTok SquareOpenToken *> parseType <* satTok SquareCloseToken
  40                 >>= \t.pure $ ListType t) <|>
  41         (satTok BraceOpenToken *> parseType <* satTok CommaToken
  42                 >>= \t1->parseType <* satTok BraceCloseToken
  43                 >>= \t2->pure $ TupleType t1 t2) <|>
  44         (parseIdent >>= \e.pure $ IdType e) <|>
  45         empty
  46
  47 parseExpr :: Parser Token Expr
  48 parseExpr =
  49         (satTok BraceOpenToken *> parseExpr <* satTok BraceCloseToken) <|>
  50         (satTok BraceOpenToken *> parseExpr <* satTok CommaToken
  51                 >>= \e1->parseExpr <* satTok BraceCloseToken
  52                 >>= \e2->pure $ TupleExpr e1 e2) <|>
  53         trans1 EmptyListToken EmptyListExpr <|>
  54         trans2 TrueToken (const $ BoolExpr True) <|>
  55         trans2 FalseToken (const $ BoolExpr True) <|>
  56         trans2 (NumberToken zero) (\(NumberToken i)->IntExpr i) <|>
  57         trans2 (CharToken zero) (\(CharToken c)->CharExpr c) <|>
  58         (parseOp1 >>= \o->parseExpr >>= \e.pure $ Op1Expr o e) <|>
  59         (parseIdent <* satTok BraceOpenToken
  60                 >>= \i->parseActArgs <* satTok BraceCloseToken
  61                 >>= \es->pure $ FunExpr i es) <|>
  62         (parseIdent >>= \i. parseFieldSelector >>= \f.pure $ VarExpr i f)
  63         //TODO Parse Binary operators
  64
  65 parseActArgs :: Parser Token [Expr]
  66 parseActArgs =
  67         //One argument
  68         (some (parseExpr <* satTok CommaToken) >>= \es->parseExpr >>= \e.pure [e:es]) <|>
  69         //Two or more arguments
  70         (parseExpr >>= \e->pure [e]) <|>
  71         //Zero arguments, dit moet nog mooier kunnen
  72         empty
  73
  74 parseOp1 :: Parser Token Op1
  75 parseOp1 = trans1 DashToken UnMinus <|>
  76         trans1 ExclamationToken UnNegation
  77
  78 parseOp2 :: Parser Token Op2
  79 parseOp2 = trans1 StarToken BiTimes <|> trans1 SlashToken BiDivide <|>
  80         trans1 PercentToken BiMod <|> trans1 EqualsToken BiEquals <|>
  81         trans1 LesserToken BiLesser <|> trans1 BiggerToken BiGreater <|>
  82         trans1 LesserEqToken BiLesserEq <|> trans1 PlusToken BiPlus <|>
  83         trans1 GreaterEqToken BiGreaterEq <|> trans1 DashToken BiMinus <|>
  84         trans1 NotEqualToken BiUnEqual <|> trans1 AmpersandsToken BiAnd <|>
  85         trans1 PipesToken BiOr <|> trans1 ColonToken BiCons
  86
  87 parseFieldSelector :: Parser Token (Maybe FieldSelector)
  88 parseFieldSelector = optional (satTok DotToken *> (
  89         (parseIdent >>= (\i.if (i == "hd") (pure FieldHd) empty)) <|>
  90         (parseIdent >>= \i.if (i == "tl") (pure FieldTl) empty) <|>
  91         (parseIdent >>= \i.if (i == "fst") (pure FieldFst) empty) <|>
  92         (parseIdent >>= \i.if (i == "snd") (pure FieldSnd) empty)))
  93
  94 trans2 :: TokenValue (TokenValue -> a) -> Parser Token a
  95 trans2 t f = satTok t >>= \(_, r).pure (f r)
  96
  97 trans1 :: TokenValue a -> Parser Token a
  98 trans1 t r = trans2 t $ const r
  99
 100 satTok :: TokenValue -> Parser Token Token
 101 satTok t = satisfy ((===) t)
 102
 103 parseIdent :: Parser Token String
 104 parseIdent = trans2 (IdentToken []) (\(IdentToken e).toString e)
 105
 106 instance toString AST where
 107         toString (AST v f) = concat (print v ++ ["\n":print f])
 108
 109 class print a :: a -> [String]
 110
 111 instance print [a] | print a where
 112         print [] = ["\n"]
 113         print [v:vs] = print v ++ ["\n":print vs]
 114
 115 instance print VarDecl where
 116         print (VarDecl i t e) = print t ++ [" ":i:"=":print e] ++ [";"]
 117 instance print FunDecl where
 118         print _ = ["Function printing not yet implemented"]
 119
 120 instance print Type where
 121         print (TupleType t1 t2) = ["(":print t1] ++ [", ":print t2] ++ [")"]
 122         print (ListType t) = ["[":print t] ++ ["]"]
 123         print (IdType s) = [s]
 124         print IntType = ["Int"]
 125         print BoolType = ["Bool"]
 126         print CharType = ["Char"]
 127         print VarType = ["var"]
 128
 129 instance print Expr where
 130         print (VarExpr i Nothing) = [i]
 131         print (VarExpr i (Just mf)) = [i, case mf of
 132                 FieldHd = ".hd"; FieldTl = ".tl"
 133                 FieldSnd = ".snd"; FieldFst = ".fst"]
 134         print (Op2Expr e1 o e2) = print e1 ++ [case o of
 135                 BiPlus = "+"; BiMinus = "-"; BiTimes = "*"; BiDivide = "/"
 136                 BiMod = "%"; BiEquals = "="; BiLesser = "<"; BiGreater = ">"
 137                 BiLesserEq = "<="; BiGreaterEq = ">="; BiUnEqual = "!=";
 138                 BiAnd = "&&"; BiOr = "||"; BiCons = ":"
 139                 :print e2]
 140         print (Op1Expr o e) = [case o of
 141                 UnNegation = "!"; UnMinus = "-"
 142                 :print e]
 143         print (IntExpr i) = [toString i]
 144         print (CharExpr c) = ["\'", case c of
 145                 '\b' = "\\b"; '\f' = "\\f"; '\n' = "\\n"
 146                 '\r' = "\\r"; '\t' = "\\t"; '\v' = "\\v"
 147                 c = if (c == toChar 7) "\\a" (toString c)
 148                 ,"\'"]
 149         print (BoolExpr b) = [toString b]
 150         print (FunExpr i es) = pe ++ flatten [[",":x]\\x<-tl pes]
 151                 where [pe:pes] = map print es
 152         print EmptyListExpr = ["[]"]
 153         print (TupleExpr e1 e2) = ["(":print e1] ++ [",":print e2] ++ [")"]