X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=lex.icl;h=de200df2f4dcd62930ea1e74bf20f97fb7b9872a;hb=4766205e7035a58c8a1fa1557b6e14577ed26f32;hp=876e3020563af235fb2604aac839e35132111f55;hpb=1ee1a90bd336cd6c44ab4b51dd7f4946447ce8a8;p=cc1516.git diff --git a/lex.icl b/lex.icl index 876e302..de200df 100644 --- a/lex.icl +++ b/lex.icl @@ -1,69 +1,80 @@ implementation module lex import Control.Monad -import Data.Either -import Data.Maybe -import Data.Map -import Data.Func +import Data.Either, Data.Maybe, Data.Map, Data.Func import StdString import StdTuple import StdBool import StdList import StdChar -import qualified Text -SingleCharTokens :: Map Char Token +SingleCharTokens :: Map Char TokenValue SingleCharTokens = fromList [ ('(', BraceOpenToken), (')', BraceCloseToken), ('{', CBraceOpenToken), ('}', CBraceCloseToken), ('[', SquareOpenToken), (']', SquareCloseToken), (',', CommaToken), (':', ColonToken), (';', SColonToken), - ('.', DotToken), ('+', PlusToken), ('-', DashToken), ('*', StarToken), - ('/', SlashToken), ('%', PercentToken), ('=', AssignmentToken), - ('<', LesserToken), ('>', BiggerToken), ('!', ExclamationToken)] + ('.', DotToken), ('+', PlusToken), ('*', StarToken), ('/', SlashToken), + ('%', PercentToken), ('=', AssignmentToken), ('<', LesserToken), + ('>', BiggerToken), ('!', ExclamationToken)] EscapeMap :: Map Char Char EscapeMap = fromList [('a', toChar 7), ('b', '\b'), ('f', '\f'), ('n', '\n'), ('r', '\r'), ('t', '\t'), ('v', '\v')] lexer :: [Char] -> LexerOutput -lexer [] = Right [] -lexer x = case lex x of - (Right t, rest) = lexer rest >>= \ts.Right [t:ts] - (Left e, _) = Left e +lexer x = lexer` x 1 + where + lexer` :: [Char] Int -> LexerOutput + lexer` [] i = Right [] + lexer` x i = case lex x i of + (Right t, rest, i) = lexer` rest i >>= \ts.Right [t:ts] + (Left e, _, _) = Left e -lex :: [Char] -> (Either String Token, [Char]) -lex [] = (Right EndOfFileToken, []) -lex ['/':'/':xs] = lex $ dropWhile ((<>) '\n') xs -lex ['/':'*':xs] = lex $ tl $ map snd $ dropWhile ((<>) ('*', '/')) $ zip2 [zero:xs] xs -lex ['v':'a':'r':xs] = (Right VarToken, xs) -lex ['V':'o':'i':'d':xs] = (Right VoidToken, xs) -lex ['r':'e':'t':'u':'r':'n':xs] = (Right ReturnToken, xs) -lex ['i':'f':xs] = (Right IfToken, xs) -lex ['e':'l':'s':'e':xs] = (Right ElseToken, xs) -lex ['w':'h':'i':'l':'e':xs] = (Right WhileToken, xs) -lex ['T':'r':'u':'e':xs] = (Right TrueToken, xs) -lex ['F':'a':'l':'s':'e':xs] = (Right FalseToken, xs) -lex ['I':'n':'t':xs] = (Right IntTypeToken, xs) -lex ['C':'h':'a':'r':xs] = (Right CharTypeToken, xs) -lex ['B':'o':'o':'l':xs] = (Right BoolTypeToken, xs) -lex [':':':':xs] = (Right DoubleColonToken, xs) -lex ['!':'=':xs] = (Right NotEqualToken, xs) -lex ['<':'=':xs] = (Right LesserEqToken, xs) -lex ['>':'=':xs] = (Right GreaterEqToken, xs) -lex ['=':'=':xs] = (Right EqualsToken, xs) -lex ['&':'&':xs] = (Right AmpersandsToken, xs) -lex ['|':'|':xs] = (Right PipesToken, xs) -lex ['-':'>':xs] = (Right ArrowToken, xs) -lex ['\'':x:'\'':xs] = (Right (CharToken x), xs) +ret:: TokenValue [Char] Int -> (Either String Token, [Char], Int) +ret tv rest i = (Right (i, tv), rest, i) + +err :: String Int -> (Either String Token, [Char], Int) +err s i = (Left ("Line " +++ toString i +++ ": " +++ s), [], i) + +lex :: [Char] -> (Int -> (Either String Token, [Char], Int)) +lex [] = ret EndOfFileToken [] +lex ['/':'/':xs] = lex (dropWhile ((<>) '\n') xs) +lex ['/':'*':xs] = \i.let (c, r) = span ((<>) ('*','/')) $ zip2 [' ':xs] xs in + lex (tl $ map snd $ tl $ r) (i + length [x\\(x, _)<-c | x == '\n']) +lex ['v':'a':'r':xs] = ret VarToken xs +lex ['V':'o':'i':'d':xs] = ret VoidToken xs +lex ['r':'e':'t':'u':'r':'n':xs] = ret ReturnToken xs +lex ['i':'f':xs] = ret IfToken xs +lex ['e':'l':'s':'e':xs] = ret ElseToken xs +lex ['w':'h':'i':'l':'e':xs] = ret WhileToken xs +lex ['T':'r':'u':'e':xs] = ret TrueToken xs +lex ['F':'a':'l':'s':'e':xs] = ret FalseToken xs +lex ['I':'n':'t':xs] = ret IntTypeToken xs +lex ['C':'h':'a':'r':xs] = ret CharTypeToken xs +lex ['B':'o':'o':'l':xs] = ret BoolTypeToken xs +lex [':':':':xs] = ret DoubleColonToken xs +lex ['!':'=':xs] = ret NotEqualToken xs +lex ['<':'=':xs] = ret LesserEqToken xs +lex ['>':'=':xs] = ret GreaterEqToken xs +lex ['=':'=':xs] = ret EqualsToken xs +lex ['&':'&':xs] = ret AmpersandsToken xs +lex ['|':'|':xs] = ret PipesToken xs +lex ['-':'>':xs] = ret ArrowToken xs +lex ['\'':x:'\'':xs] = ret (CharToken x) xs lex ['\'':'\\':x:'\'':xs] = case get x EscapeMap of - Just t = (Right (CharToken t), xs) - _ = (Left ("Unknown escape: \\" +++ toString x), []) -lex [x:xs] -# t = get x SingleCharTokens -| isJust t = (Right (fromJust t), xs) -| isSpace x = lex xs -| isDigit x = let (is, xs`) = span isDigit xs in - (Right (NumberToken [x:is]), xs`) -| isAlpha x = let (is, xs`) = span (\c.isAlphanum c || c == '_') xs in - (Right (IdentToken [x:is]), xs`) -| otherwise = (Left ("Unexpected character: " +++ toString x), []) + Just t = ret (CharToken t) xs + _ = err ("Unknown escape: \\" +++ toString x) +lex ['-':t=:[x:xs]] +| isDigit x = let (n, r) = span isDigit t in + ret (NumberToken (toInt $ toString ['-':n])) r +| otherwise = ret DashToken xs +lex t=:[x:xs] = case get x SingleCharTokens of + (Just tok) = ret tok xs + Nothing + | x == '\n' = \i.lex xs (i+1) + | isSpace x = lex xs + | isDigit x = let (v, r) = span isDigit t in + ret (NumberToken (toInt $ toString v)) r + | isAlpha x = let (v, r) = span isIdent t in ret (IdentToken v) r + with isIdent c = isAlphanum c || c == '_' + | otherwise = err ("Unexpected character: " +++ toString x)