Am Donnerstag 22 April 2010 00:42:51 schrieb Renato dos Santos Leal:
I've got a university project that demands me to do a program that receive a .c file and analyze its syntax using haskell. There are just a few things that I have to analyze: literal strings, identifiers (in the program: identificadores), constants (constantes), operators (operadores) and reserverd words(palavras reservadas)
There are two major problems in the program:
(1) I've got this guard in le_bloco: | x `elem` listS = do separador (x:xs) but it doesn't seem to work. Every time I enable it I recieve this in execution time (after calling verifica)
ERROR - Cannot find "show" function for: *** Expression : verifica *** Of type : IO a
I can't reproduce that. It works here (except of the pattern match failure at the end because none of your functions handles an empty String). $ hugs CAnal __ __ __ __ ____ ___ _________________________________________ || || || || || || ||__ Hugs 98: Based on the Haskell 98 standard ||___|| ||__|| ||__|| __|| Copyright (c) 1994-2005 ||---|| ___|| World Wide Web: http://haskell.org/hugs || || Bugs: http://hackage.haskell.org/trac/hugs || || Version: September 2006 _________________________________________ Haskell 98 mode: Restart with command line option -98 to enable extensions Type :? for help CAnal> verifica Favor visualizar o codigo para ver os bugs e erros do programa Digite o nome do arquivo de entrada: hello.c #include <identificador> < <operador> stdio <identificador> . <operador> h <identificador>
<operador>
int <identificador>
main <identificador>
(){ <separador>
printf <identificador>
( <separador>
Hello <identificador>
World <identificador>
! <operador>
\n" <identificador>
); <separador>
return <palavra chave>
0
So I've made one workaround that prints the separator but stops the program...I guess the problem is doing the recursivity
(2) My second problem is: when I have one identifier or keyword alone in a line or it's the last element of it it just won't print my coment!
That's because you don't look for newlines, so int main is considered to be one token, "int\nmain".
this is the function:
pPCouI (x:xs) z
| membroPC z = do{ putStr (z ++ " <palavra chave>\n") ; le_bloco | (x:xs)} otherwise = do{putStr z ; putStr " <identificador>\n" ; | le_bloco
(x:xs)}
*Please help me solving those problems as soon as possible!*
Here is the whole program:
listO = ['+', '-', '*', '/', '%', '^', '=', '>', '<', '.', '|', '&', '!', '~'] listS = [';', '{', '(', ')', '}', '[', ']', ','] listC = ['0','1'..'9'] listCF = listC ++ ['.'] listA = listO ++ listS ++ [' '] listPC = ["auto","double","int","struct","break","else","long","switch","case",
"enum","register","typedef","char","extern","return","union","const",
"float","short","unsigned","continue","for","signed","void","default", "goto","sizeof","volatile","do","if","static","while"]
verifica = do putStr ("Favor visualizar o codigo para ver os bugs e erros do programa\n") putStr ("Digite o nome do arquivo de entrada: ") arqent <- getLine texto <- readFile arqent le_bloco texto
le_bloco (x:xs)
| x `elem` listO = do operador (x:xs) | x `elem` listC = do cnum (x:xs)
-- | x `elem` listS = do separador (x:xs)
| x `elem` listS = do{ putStr[x] ; putStr " <separador>\n" } | x == '"' = litstr (xs) | x /= ' ' = pchave (x:xs) [] | x == ' ' = le_bloco xs | otherwise = do { putStr "Outro\n" ; le_bloco xs }
separador (x:xs)
| x `elem` listS = do{ putStr [x] ; separador xs} | otherwise = do{ putStr " <separador>\n" ; le_bloco xs}
That should probably be le_bloco (x:xs) in the otherwise-branch, too. Thus it failed to see that "Hello World\n" was a string literal. And it wouldn't treat int x=3,y=4; correctly.
cnum (x:xs)
| x `elem` listCF = do{ putChar x ; cnum xs} | otherwise = do{ putStr "
\n" ; le_bloco (x:xs)} operador (x:xs)
| x `elem` listO = do{ putChar x ; operador xs} | otherwise = do{ putStr " <operador>\n" ; le_bloco (x:xs)}
litstr (x:xs)
| x /= '"' = do{ putChar x ; litstr xs} | otherwise = do{ putStr " <literal string>\n" ; le_bloco xs}
pchave (x:xs) ys
| x `notElem` listA = pchave xs (ys++[x]) | otherwise = pPCouI (x:xs) ys
pPCouI (x:xs) z
| membroPC z = do{ putStr (z ++ " <palavra chave>\n") ; le_bloco | (x:xs)} otherwise = do{putStr z ; putStr " <identificador>\n" ; | le_bloco
(x:xs)}
membroPC x
| x `elem` listPC = True | otherwise = False
I'm sorry for the bad english, it's been a while since the last time i used it =) Ah, I'm just starting to learn Haskell, first time i've seen it was like a month ago so pretend that I know nothing