{-# LANGUAGE FlexibleContexts #-}
module PascalBasics where
import Text.Parsec.Combinator
import Text.Parsec.Char
import Text.Parsec.Prim
import Text.Parsec.Token
import Text.Parsec.Language
import Data.Char
builtin = ["succ", "pred", "low", "high", "ord", "inc", "dec", "exit", "break", "continue", "length"]
pascalLanguageDef
= emptyDef
{ commentStart = "(*"
, commentEnd = "*)"
, commentLine = "//"
, nestedComments = False
, identStart = letter <|> oneOf "_"
, identLetter = alphaNum <|> oneOf "_"
, opLetter = letter
, reservedNames = [
"begin", "end", "program", "unit", "interface"
, "implementation", "and", "or", "xor", "shl"
, "shr", "while", "do", "repeat", "until", "case", "of"
, "type", "var", "const", "out", "array", "packed"
, "procedure", "function", "with", "for", "to"
, "downto", "div", "mod", "record", "set", "nil"
, "cdecl", "external", "if", "then", "else"
] -- ++ builtin
, caseSensitive = False
}
preprocessorSwitch :: Stream s m Char => ParsecT s u m String
preprocessorSwitch = do
try $ string "{$"
s <- manyTill (noneOf "\n") $ char '}'
return s
caseInsensitiveString s = do
mapM_ (\a -> satisfy (\b -> toUpper a == toUpper b)) s <?> s
return s
pas = patch $ makeTokenParser pascalLanguageDef
where
patch tp = tp {stringLiteral = stringL}
comment = choice [
char '{' >> notFollowedBy (char '$') >> manyTill anyChar (try $ char '}')
, (try $ string "(*") >> manyTill anyChar (try $ string "*)")
, (try $ string "//") >> manyTill anyChar (try newline)
]
comments = do
spaces
skipMany $ do
preprocessorSwitch <|> comment
spaces
stringL = do
(char '\'')
s <- (many $ noneOf "'")
(char '\'')
ss <- many $ do
(char '\'')
s' <- (many $ noneOf "'")
(char '\'')
return $ '\'' : s'
comments
return $ concat (s:ss)