implementation module lex
import Control.Monad, Control.Applicative
-import Data.Either, Data.Func
+import Data.Either, Data.Func, Data.Maybe, Data.Functor
from StdFunc import o
import StdBool
import StdList
import StdChar
+import StdString
+
+from Text import class Text(textSize,concat), instance Text String
import yard
lexer :: [Char] -> LexerOutput
-lexer r = case runParser lexProgram r of
+lexer r = case runParser (lexProgram 1 1) r of
(Right p, _) = Right p
- (Left e, _) = Left $ toString e
+ (Left e, _) = Left e
+
+lexProgram :: Int Int -> Parser Char [Token]
+lexProgram line column = lexToken >>= \t->case t of
+ LexEOF = pure []
+ (LexItemError e) = fail <?>
+ PositionalError line column ("LexerError: " +++ e)
+ (LexToken c t) = lexProgram line (column+c)
+ >>= \rest->pure [{line=line, column=column, token=t}:rest]
+ LexNL = lexProgram (line+1) 1
+ (LexSpace l c) = lexProgram (line+l) (column+c)
-lexProgram :: Parser Char [Token]
-lexProgram = some lexToken <* many (satisfy isSpace) <* eof
- >>= \ts->pure (map (\t->(0, 0, t)) ts)
+:: LexItem
+ = LexToken Int TokenValue
+ | LexSpace Int Int
+ | LexNL
+ | LexEOF
+ | LexItemError String
-lexToken :: Parser Char TokenValue
+lexToken :: Parser Char LexItem
lexToken =
- //Comments
- (list (fromString "//") >>| until top ((item '\n' >>| return Void) <|> eof) >>| lexToken) <|>
- (list (fromString "/*") >>| until top (list (fromString "*/")) >>| lexToken) <|>
+ //Comments
+ lexBlockComment <|> lexComment <|>
//Keyword tokens
- (lexKw "var" VarToken) <|>
- (lexKw "Void" VoidToken) <|>
- (lexKw "return" ReturnToken) <|>
- (lexKw "if" IfToken) <|>
- (lexKw "else" ElseToken) <|>
- (lexKw "while" WhileToken) <|>
- (lexKw "True" TrueToken) <|>
- (lexKw "False" FalseToken) <|>
- (lexKw "Int" IntTypeToken) <|>
- (lexKw "Bool" BoolTypeToken) <|>
- (lexKw "Char" CharTypeToken) <|>
- //Escape chars tokens
- (liftM CharToken $ item '\'' *> item '\\' *> lexEscape <* item '\'') <|>
- //Normal chars tokens
- (liftM CharToken $ item '\'' *> satisfy ((<>) '\'') <* item '\'') <|>
+ lexKw "var" VarToken <|> lexKw "Void" VoidToken <|>
+ lexKw "return" ReturnToken <|> lexKw "if" IfToken <|>
+ lexKw "else" ElseToken <|> lexKw "while" WhileToken <|>
+ lexKw "True" TrueToken <|> lexKw "False" FalseToken <|>
+ lexKw "Int" IntTypeToken <|> lexKw "Bool" BoolTypeToken <|>
+ lexKw "Char" CharTypeToken <|>
+ //Character tokens
+ lexEscape <|> lexCharacter <|>
//Two char ops tokens
- (lexOp "::" DoubleColonToken) <|> (lexOp "!=" NotEqualToken) <|>
- (lexOp "<=" LesserEqToken) <|> (lexOp ">=" GreaterEqToken) <|>
- (lexOp "==" EqualsToken) <|> (lexOp "&&" AmpersandsToken) <|>
- (lexOp "||" PipesToken) <|> (lexOp "[]" EmptyListToken) <|>
- (lexOp "->" ArrowToken) <|>
+ lexWord "::" DoubleColonToken <|> lexWord "!=" NotEqualToken <|>
+ lexWord "<=" LesserEqToken <|> lexWord ">=" GreaterEqToken <|>
+ lexWord "==" EqualsToken <|> lexWord "&&" AmpersandsToken <|>
+ lexWord "||" PipesToken <|> lexWord "[]" EmptyListToken <|>
+ lexWord "->" ArrowToken <|>
//One char ops tokens
- (lexOp "(" BraceOpenToken) <|>
- (lexOp ")" BraceCloseToken) <|> (lexOp "{" CBraceOpenToken) <|>
- (lexOp "}" CBraceCloseToken) <|> (lexOp "[" SquareOpenToken) <|>
- (lexOp "]" SquareCloseToken) <|> (lexOp "," CommaToken) <|>
- (lexOp ":" ColonToken) <|> (lexOp ";" SColonToken) <|>
- (lexOp "." DotToken) <|> (lexOp "+" PlusToken) <|>
- (lexOp "*" StarToken) <|> (lexOp "/" SlashToken) <|>
- (lexOp "%" PercentToken) <|> (lexOp "=" AssignmentToken) <|>
- (lexOp "<" LesserToken) <|> (lexOp ">" BiggerToken) <|>
- (lexOp "!" ExclamationToken) <|> (lexOp "-" DashToken) <|>
- //Number tokens
- (liftM (NumberToken o toInt o toString) $ some $ satisfy isDigit) <|>
- //Ident tokens
- (liftM IdentToken $ some $ satisfy isIdentChar) <|>
- (satisfy isSpace >>| lexToken)
-// (eof >>| pure EndOfFileToken)
+ lexWord "(" BraceOpenToken <|>
+ lexWord ")" BraceCloseToken <|> lexWord "{" CBraceOpenToken <|>
+ lexWord "}" CBraceCloseToken <|> lexWord "[" SquareOpenToken <|>
+ lexWord "]" SquareCloseToken <|> lexWord "," CommaToken <|>
+ lexWord ":" ColonToken <|> lexWord ";" SColonToken <|>
+ lexWord "." DotToken <|> lexWord "+" PlusToken <|>
+ lexWord "*" StarToken <|> lexWord "/" SlashToken <|>
+ lexWord "%" PercentToken <|> lexWord "=" AssignmentToken <|>
+ lexWord "<" LesserToken <|> lexWord ">" BiggerToken <|>
+ lexWord "!" ExclamationToken <|> lexWord "-" DashToken <|>
+ //Number and identifier tokens
+ lexNumber <|> lexIdentifier <|>
+ (item '\n' >>| pure LexNL) <|>
+ (satisfy isSpace >>| (pure $ LexSpace 0 1)) <|>
+ (eof >>| pure LexEOF)
where
+ lexWord :: String TokenValue -> Parser Char LexItem
+ lexWord s tv = list (fromString s) >>| pure (LexToken (textSize s) tv)
+
+ lexKw :: String TokenValue -> Parser Char LexItem
+ lexKw kw tv = lexWord kw tv <* check (not o isIdentChar)
+
+ lexUntilNL = top until (eof <|> (item '\n' >>| pure Void))
+
+ lexComment :: Parser Char LexItem
+ lexComment = list (fromString "//") >>| lexUntilNL
+ >>= \chars->pure LexNL
+
+ lexBlockComment :: Parser Char LexItem
+ lexBlockComment = list (fromString "/*")
+ >>| (top until (list (fromString "*/")))
+ >>= \chars->pure $ widthHeight chars 0 0
+ where
+ widthHeight :: [Char] Int Int -> LexItem
+ widthHeight [] l c = LexSpace l c
+ widthHeight ['\n':xs] l _ = widthHeight xs (l+1) 0
+ widthHeight [x:xs] l c = widthHeight xs l (c+1)
+
+ lexNumber :: Parser Char LexItem
+ lexNumber = toString <$> some (satisfy isDigit)
+ >>= \si->pure $ LexToken (textSize si) (NumberToken $ toInt si)
+
+ lexIdentifier :: Parser Char LexItem
+ lexIdentifier = toString <$> some (satisfy isIdentChar)
+ >>= \si->pure $ LexToken (textSize si) (IdentToken si)
+
isIdentChar c = isAlphanum c || c == '_'
- lexOp s tv = list (fromString s) >>| pure tv
- lexKw kw tv = lexOp kw tv <* check (not o isIdentChar) >>| pure tv
- lexEscape = (
- lexOp "a" (toChar 7) <|> lexOp "b" '\b' <|> lexOp "f" '\f' <|>
- lexOp "n" '\n' <|> lexOp "r" '\t' <|> lexOp "v" '\v' <|>
- lexOp "'" '\'') <?> ("Unknown escape", 0)
+
+ lexCharacter :: Parser Char LexItem
+ lexCharacter = item '\'' *> satisfy ((<>) '\'') <* item '\''
+ >>= \char->pure $ LexToken 3 (CharToken char)
+
+ lexEscape :: Parser Char LexItem
+ lexEscape = item '\'' *> item '\\' *> top <* item '\''
+ >>= \char->pure case char of
+ 'a' = LexToken 4 (CharToken $ toChar 7)
+ 'b' = LexToken 4 (CharToken '\b')
+ 'b' = LexToken 4 (CharToken '\b')
+ 'f' = LexToken 4 (CharToken '\f')
+ 'n' = LexToken 4 (CharToken '\n')
+ 'r' = LexToken 4 (CharToken '\t')
+ 'v' = LexToken 4 (CharToken '\v')
+ '\'' =LexToken 4 (CharToken '\'')
+ c = (LexItemError $ "Unknown escape: " +++ toString c)
repositories / cc1516.git / blobdiff