KyotoCabinet-0.1: examples/kclangcex.hs

{-# LANGUAGE ScopedTypeVariables #-}
{-
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-}

module Main where

import Database.KyotoCabinet.Db

import Control.Exception
import qualified Data.ByteString.Char8 as BS
import Prelude hiding (catch)

import System.Mem

visitfull :: KcVisitFull
visitfull key val = do
  putStrLn (BS.unpack key ++ ":" ++ BS.unpack val)
  return KCVISNOP

visitempty :: KcVisitEmpty
visitempty key = do
  putStrLn (BS.unpack key ++ " is missing")
  return $ KCVISNOP
--  let rv = BS.pack ("foo"++"bar")
--  return $ KCVISSET rv

main = do
  -- create and open the database
  kcwithdbopen "casket.kch" [KCOWRITER, KCOCREATE] $ \db -> do

    -- store records
    (do kcdbset db (BS.pack "foo") (BS.pack "hop")
        kcdbset db (BS.pack "bar") (BS.pack "step")
        kcdbset db (BS.pack "baz") (BS.pack "jump")
        kcdbappend db (BS.pack "baz") (BS.pack "run")
        kcdbappend db (BS.pack "baz") (BS.pack "fly"))
      `catch` \(exn::KcException) -> putStrLn ("set error: "++show exn)

    -- retrieve a record
    (do vbuf <- kcdbget db (BS.pack "foo")
        putStrLn (BS.unpack vbuf))
      `catch` \(exn::KcException) -> putStrLn ("get error: "++show exn)

    -- traverse records
    kcwithdbcursor db $ \cur -> do
      kccurjump cur
      let loop = do (key, val) <- kccurget cur True
                    putStrLn (BS.unpack key ++ ":" ++ BS.unpack val)
                    loop
      loop `catch` \(exn::KcException) -> return ()

    -- retrieve a record with visitor
    kcdbaccept db (BS.pack "dummy") visitfull visitempty False
      `catch` \(exn::KcException) ->
        kcdbaccept db (BS.pack "foo") visitfull visitempty False
          `catch` \(exn::KcException) -> putStrLn ("accept error: "++show exn)

    -- traverse records with visitor
    kcdbiterate db visitfull False
      `catch` \(exn::KcException) -> putStrLn ("iterate error: "++show exn)

    (do prefixes <- kcdbmatchprefix db (BS.pack "b") 3
        putStrLn (show prefixes))
      `catch` \(exn::KcException) -> putStrLn ("prefix error: "++show exn)

    (do prefixes <- kcdbmatchregex db (BS.pack ".a.*") 10
        putStrLn (show prefixes))
      `catch` \(exn::KcException) -> putStrLn ("regexp error: "++show exn)

    kcwithlazydbcursorcontext $ \cc -> do
      cur <- kclazydbcursor db cc
      vals <- kclazycurgetvalues cc cur (BS.pack "baz")
      putStrLn (show vals)