eVEXZS6W

1import Text.ParserCombinators.ReadP
2import Data.Char (isAlpha)
3import qualified Data.Text as T
4
5tableParser :: ReadP String
6tableParser = do
7    string "create"
8    many1 (satisfy (\x -> x == ' '))
9    --skipSpaces()
10    string "table"
11    many1 (satisfy (\x -> x == ' '))
12    option "" (string "if")
13    many (satisfy (\x -> x == ' '))
14    option "" (string "not")
15    many (satisfy (\x -> x == ' '))
16    option "" (string "exists")
17    many (satisfy (\x -> x == ' '))
18    tableName <- munch1 (\x -> (isAlpha(x) || x == '_') && x /= '(')
19    return tableName
20
21exprParser = do
22    expr1 <- munch (\c -> c /= ';')
23    satisfy (== ';')
24    return expr1
25
26testIt x = do
27    readP_to_S tableParser x
28
29strip :: String -> String
30strip s = T.unpack (T.strip $ T.pack s)
31
32{-
33-}
34parseExpr :: String -> [String]
35parseExpr s =
36    case readP_to_S exprParser s of
37         [] -> []
38         ((found, remaining): _) ->
39             (strip found):(parseExpr remaining)
40
41{-
42    - example to run
43    - map parseTablename (parseExpr "create table if not exists my_table ()\
44        \ ; create table if my_table_again \
45        \ () ;")
46    - > ["my_table", "my_table_again"]
47-}
48parseTablename s =
49    case readP_to_S tableParser s of
50         [] -> ""
51         lst@(_) -> (fst $ last lst)