1 implementation module parse
6 from StdFunc import const, o
11 import Control.Applicative
13 from Data.List import intercalate, replicate, instance Functor []
14 from Text import class Text(concat), instance Text String
20 parser :: LexerOutput -> ParserOutput
21 parser (Left e) = Left $ toString $ LexError e
22 parser (Right r) = case runParser parseProgram r of
23 (Right p, _) = Right p
24 (Left e, _) = Left $ toString e
26 parseProgram :: Parser Token AST
27 parseProgram = liftM2 AST (many parseVarDecl) (some parseFunDecl)
29 parseFunDecl :: Parser Token FunDecl
30 parseFunDecl = liftM5 FunDecl
31 (parseIdent <* satTok BraceOpenToken)
32 (parseSepList CommaToken parseIdent <* satTok BraceCloseToken)
33 (parseFunType <* satTok CBraceOpenToken)
35 (many parseStmt <* satTok CBraceCloseToken)
37 parseStmt :: Parser Token Stmt
38 parseStmt = parseIfStmt <|> parseWhileStmt <|>
39 parseSColon parseAssStmt <|> parseSColon parseReturnStmt <|>
40 (liftM FunStmt (parseSColon parseFunCall))
42 parseSColon :: (Parser Token a) -> Parser Token a
43 parseSColon p = p <* satTok SColonToken
45 parseReturnStmt :: Parser Token Stmt
47 satTok ReturnToken *> liftM ReturnStmt (optional parseExpr)
49 parseAssStmt :: Parser Token Stmt
51 liftM2 AssStmt (parseVarDef <* satTok AssignmentToken) parseExpr
53 parseIfStmt :: Parser Token Stmt
54 parseIfStmt = liftM3 IfStmt
55 (satTok IfToken *> parseBBraces parseExpr)
56 (parseBlock <|> parseOneLine)
58 (optional (satTok ElseToken *> (parseBlock<|> parseOneLine))))
60 parseWhileStmt :: Parser Token Stmt
61 parseWhileStmt = satTok WhileToken *>
62 liftM2 WhileStmt (parseBBraces parseExpr) parseBlock
64 parseBlock :: Parser Token [Stmt]
65 parseBlock = parseBCBraces (many parseStmt)
67 parseOneLine :: Parser Token [Stmt]
68 //first pure makes singleton list from the statement
69 parseOneLine = liftM pure parseStmt
71 parseBBraces :: (Parser Token a) -> Parser Token a
72 parseBBraces p = satTok BraceOpenToken *> p <* satTok BraceCloseToken
74 parseBCBraces :: (Parser Token a) -> Parser Token a
75 parseBCBraces p = satTok CBraceOpenToken *> p <* satTok CBraceCloseToken
77 parseBSqBraces :: (Parser Token a) -> Parser Token a
78 parseBSqBraces p = satTok SquareOpenToken *> p <* satTok SquareCloseToken
80 parseFunType :: Parser Token FunType
81 parseFunType = satTok DoubleColonToken *>
82 (parseInOutType <|> (liftM (FunType []) parseVoidOrType))
84 parseInOutType :: Parser Token FunType
85 parseInOutType = liftM2 FunType
86 (some parseType <* satTok ArrowToken) parseVoidOrType
88 parseVoidOrType :: Parser Token (Maybe Type)
89 parseVoidOrType = (satTok VoidToken *> pure Nothing) <|>
90 (liftM Just parseType)
92 parseVarDecl :: Parser Token VarDecl
93 parseVarDecl = liftM3 VarDecl
94 (parseType <|> trans1 VarToken VarType )
95 (parseIdent <* satTok AssignmentToken)
96 (parseExpr <* satTok SColonToken)
98 parseType :: Parser Token Type
100 trans1 IntTypeToken IntType <|>
101 trans1 CharTypeToken CharType <|>
102 trans1 BoolTypeToken BoolType <|>
103 (liftM ListType (parseBSqBraces parseType)) <|>
105 (satTok BraceOpenToken *> parseType <* satTok CommaToken)
106 (parseType <* satTok BraceCloseToken)) <|>
107 (liftM IdType parseIdent)
109 //TODO hieronder omzetten naar liftm notatie
110 parseExpr :: Parser Token Expr
111 parseExpr = //Operators in order of binding strength
112 parseOpR (trans1 ColonToken BiCons) $
113 parseOpR (trans1 PipesToken BiOr) $
114 parseOpR (trans1 AmpersandsToken BiAnd) $
115 parseOpR (trans1 EqualsToken BiEquals <|>
116 trans1 LesserToken BiLesser <|>
117 trans1 BiggerToken BiGreater <|>
118 trans1 LesserEqToken BiLesserEq <|>
119 trans1 GreaterEqToken BiGreaterEq <|>
120 trans1 NotEqualToken BiUnEqual) $
121 parseOpL (trans1 PlusToken BiPlus <|>
122 trans1 DashToken BiMinus) $
123 parseOpL (trans1 StarToken BiTimes <|>
124 trans1 SlashToken BiDivide <|>
125 trans1 PercentToken BiMod) $ parseBasicExpr
127 parseOpR :: (Parser Token Op2) (Parser Token Expr) -> Parser Token Expr
128 parseOpR ops prev = prev >>= \e1->optional (
129 ops >>= \op->parseOpR ops prev >>= \e->pure (op, e)
130 ) >>= \moe->pure $ maybe e1 (\(op,e2)->Op2Expr e1 op e2) moe
132 parseOpL :: (Parser Token Op2) (Parser Token Expr) -> Parser Token Expr
133 parseOpL ops prev = prev >>= \e1->many (
134 ops >>= \op->prev >>= \e->pure (op, e)
135 ) >>= \moe->foldM (\e->(\(op,e2)->pure $ Op2Expr e op e2)) e1 moe
137 parseBasicExpr :: Parser Token Expr
139 (satTok BraceOpenToken *> parseExpr <* satTok CommaToken
140 >>= \e1->parseExpr <* satTok BraceCloseToken
141 >>= \e2->pure $ TupleExpr e1 e2) <|>
142 (parseFunCall >>= \fc->pure $ FunExpr fc) <|>
143 parseBBraces parseExpr <|>
144 trans1 EmptyListToken EmptyListExpr <|>
145 trans2 TrueToken (const $ BoolExpr True) <|>
146 trans2 FalseToken (const $ BoolExpr False) <|>
147 trans2 (NumberToken zero) (\(NumberToken i)->IntExpr i) <|>
148 trans2 (CharToken zero) (\(CharToken c)->CharExpr c) <|>
149 (parseOp1 >>= \o->parseExpr >>= \e.pure $ Op1Expr o e) <|>
150 (parseVarDef >>= \ve->pure $ VarExpr ve)
152 parseFunCall :: Parser Token FunCall
153 parseFunCall = parseIdent <* satTok BraceOpenToken
154 >>= \i->parseSepList CommaToken parseExpr
155 <* satTok BraceCloseToken >>= \es->pure $ FunCall i es
157 parseVarDef :: Parser Token VarDef
158 parseVarDef = parseIdent
159 >>= \i-> many (satTok DotToken *> (
160 (parseIdent >>= (\i.if (i == "hd") (pure FieldHd) empty)) <|>
161 (parseIdent >>= \i.if (i == "tl") (pure FieldTl) empty) <|>
162 (parseIdent >>= \i.if (i == "fst") (pure FieldFst) empty) <|>
163 (parseIdent >>= \i.if (i == "snd") (pure FieldSnd) empty))
164 ) >>= \f->pure $ VarDef i f
166 parseOp1 :: Parser Token Op1
167 parseOp1 = trans1 DashToken UnMinus <|>
168 trans1 ExclamationToken UnNegation
170 trans2 :: TokenValue (TokenValue -> a) -> Parser Token a
171 trans2 t f = satTok t >>= \(_, r).pure (f r)
173 trans1 :: TokenValue a -> Parser Token a
174 trans1 t r = trans2 t $ const r
176 derive gPrint TokenValue
177 derive gEq TokenValue
178 satTok :: TokenValue -> Parser Token Token
179 satTok t = top >>= \tok=:(pos, tv) -> if (eq t tok) (return tok) (fail <?> (printToString t, pos))
181 eq (IdentToken _) (_, IdentToken _) = True
182 eq (NumberToken _) (_, NumberToken _) = True
183 eq (CharToken _) (_, CharToken _) = True
184 eq x (_, y) = gEq {|*|} x y
186 parseSepList :: TokenValue (Parser Token a) -> Parser Token [a]
188 (some (p <* satTok sep) >>= \es->p >>= \e.pure $ reverse [e:es]) <|>
189 (p >>= \e->pure [e]) <|> pure []
191 parseIdent :: Parser Token String
192 parseIdent = trans2 (IdentToken []) (\(IdentToken e).toString e)
194 instance toString AST where
195 toString (AST v f) = concat (
196 ["\n":printersperse "\n" v] ++
197 ["\n":printersperse "\n" f])
199 class print a :: a -> [String]
201 printersperse :: String [a] -> [String] | print a
202 printersperse i j = intercalate [i] (map print j)
204 instance print FunDecl where
205 print (FunDecl i as t vs ss) =
206 ["\n", i, " (":printersperse "," as] ++
208 ["{":printersperse "\n\t" vs] ++
209 ["\n":printStatements ss 1] ++ ["}"]
211 printStatements :: [Stmt] Int -> [String]
212 printStatements [] i = []
213 printStatements [s:ss] i = (case s of
214 (IfStmt b thens elses) = indent i ["if (":print b] ++ [")"] ++
215 printCodeBlock thens i ++
216 indent i ["else ":printCodeBlock elses i] ++ ["\n"]
217 (WhileStmt b dos) = indent i ["while (":print b] ++
218 [")":printCodeBlock dos i]
219 (AssStmt vardef val) =
220 indent i $ print vardef ++ ["=":print val] ++ [";\n"]
221 (FunStmt fc) = indent i $ print fc ++ [";\n"]
222 (ReturnStmt me) = indent i ["return ":maybe [""] print me] ++ [";\n"]
223 ) ++ printStatements ss i
225 printCodeBlock :: [Stmt] Int -> [String]
226 printCodeBlock [] _ = ["{}"]
227 printCodeBlock [x] i = ["\n":printStatements [x] (i+1)]
229 ["{\n":printStatements x (i+1)] ++ indent i ["}\n"]
231 indent :: Int [String] -> [String]
232 indent i rest = replicate i "\t" ++ rest
234 instance print FunType where
235 print (FunType at rt) = printersperse " " at ++
236 [if (isEmpty at) "" "->":maybe ["Void"] print rt]
238 instance print VarDecl where
239 print (VarDecl t i e) = print t ++ [" ":i:"=":print e] ++ [";"]
241 instance print Type where
242 print (TupleType t1 t2) = ["(":print t1] ++ [",":print t2] ++ [")"]
243 print (ListType t) = ["[":print t] ++ ["]"]
244 print (IdType s) = print s
245 print IntType = print "Int"
246 print BoolType = print "Bool"
247 print CharType = print "Char"
248 print VarType = print "var"
250 instance print String where
253 instance print FieldSelector where
254 print FieldHd = print "hd"
255 print FieldTl = print "tl"
256 print FieldSnd = print "snd"
257 print FieldFst = print "fst"
259 instance print VarDef where
260 print (VarDef i fs) = printersperse "." [i:flatten $ map print fs]
262 instance print FunCall where
263 print (FunCall i args) = [i,"(":printersperse "," args] ++ [")"]
265 instance print Expr where
266 print (VarExpr vd) = print vd
267 print (Op2Expr e1 o e2) = ["(":print e1] ++ [" ",case o of
268 BiPlus = "+"; BiMinus = "-"; BiTimes = "*"; BiDivide = "/"
269 BiMod = "%"; BiEquals = "="; BiLesser = "<"; BiGreater = ">"
270 BiLesserEq = "<="; BiGreaterEq = ">="; BiUnEqual = "!=";
271 BiAnd = "&&"; BiOr = "||"; BiCons = ":"
272 ," ":print e2] ++ [")"]
273 print (Op1Expr o e) = ["(",case o of
274 UnNegation = "!"; UnMinus = "-"
276 print (IntExpr i) = [toString i]
277 print (CharExpr c) = ["\'", case c of
278 '\b' = "\\b"; '\f' = "\\f"; '\n' = "\\n"
279 '\r' = "\\r"; '\t' = "\\t"; '\v' = "\\v"
280 c = if (c == toChar 7) "\\a" (toString c)
282 print (BoolExpr b) = [toString b]
283 print (FunExpr fc) = print fc
284 print EmptyListExpr = ["[]"]
285 print (TupleExpr e1 e2) = ["(":print e1] ++ [",":print e2] ++ [")"]