c756ec5 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

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Took most "instance FromRow a" and created an "instance FromRow (Maybe a)"

c756ec5Leon P Smith13 years ago

src/Database/PostgreSQL/Simple/FromRow.hs+75−4

compare with master

unifiedsplit

@@ -1,4 +1,4 @@

1−{-# LANGUAGE RecordWildCards #-}

1+{-# LANGUAGE RecordWildCards, FlexibleInstances #-}

3------------------------------------------------------------------------------

4-- |

@@ -23,8 +23,9 @@ module Database.PostgreSQL.Simple.FromRow

23 , numFieldsRemaining

24 ) where

26+import Prelude hiding (null)

26−import Control.Applicative (Applicative(..), (<$>))

27+import Control.Applicative (Applicative(..), (<$>), (<|>), (*>))

27−import Control.Monad (replicateM)

28+import Control.Monad (replicateM, replicateM_)

28import Data.ByteString (ByteString)

29import Data.ByteString (ByteString)

29import qualified Data.ByteString.Char8 as B

30import qualified Data.ByteString.Char8 as B

30import Data.Vector (Vector)

31import Data.Vector (Vector)

@@ -35,7 +36,7 @@ import Database.PostgreSQL.Simple.Internal

35import Database.PostgreSQL.Simple.Compat

36import Database.PostgreSQL.Simple.Compat

36import Database.PostgreSQL.Simple.FromField

37import Database.PostgreSQL.Simple.FromField

37import Database.PostgreSQL.Simple.Ok

38import Database.PostgreSQL.Simple.Ok

38−import Database.PostgreSQL.Simple.Types ((:.)(..))

39+import Database.PostgreSQL.Simple.Types ((:.)(..), Null)

39import Database.PostgreSQL.Simple.TypeInfo

40import Database.PostgreSQL.Simple.TypeInfo

41import Control.Monad.Trans.State.Strict

42import Control.Monad.Trans.State.Strict

@@ -120,62 +121,132 @@ numFieldsRemaining = RP $ do

120 column <- lift get

121 column <- lift get

121 return $! (\(PQ.Col x) -> fromIntegral x) (nfields rowresult - column)

122 return $! (\(PQ.Col x) -> fromIntegral x) (nfields rowresult - column)

122

123

124+null :: RowParser Null

125+null = field

126+

123instance (FromField a) => FromRow (Only a) where

127instance (FromField a) => FromRow (Only a) where

124 fromRow = Only <$> field

128 fromRow = Only <$> field

125

129

130+instance (FromField a) => FromRow (Maybe (Only a)) where

131+ fromRow = (null *> pure Nothing)

132+ <|> (Just <$> fromRow)

133+

126instance (FromField a, FromField b) => FromRow (a,b) where

134instance (FromField a, FromField b) => FromRow (a,b) where

127 fromRow = (,) <$> field <*> field

135 fromRow = (,) <$> field <*> field

128

136

137+instance (FromField a, FromField b) => FromRow (Maybe (a,b)) where

138+ fromRow = (null *> null *> pure Nothing)

139+ <|> (Just <$> fromRow)

140+

129instance (FromField a, FromField b, FromField c) => FromRow (a,b,c) where

141instance (FromField a, FromField b, FromField c) => FromRow (a,b,c) where

130 fromRow = (,,) <$> field <*> field <*> field

142 fromRow = (,,) <$> field <*> field <*> field

131

143

144+instance (FromField a, FromField b, FromField c) => FromRow (Maybe (a,b,c)) where

145+ fromRow = (null *> null *> null *> pure Nothing)

146+ <|> (Just <$> fromRow)

147+

132instance (FromField a, FromField b, FromField c, FromField d) =>

148instance (FromField a, FromField b, FromField c, FromField d) =>

133 FromRow (a,b,c,d) where

149 FromRow (a,b,c,d) where

134 fromRow = (,,,) <$> field <*> field <*> field <*> field

150 fromRow = (,,,) <$> field <*> field <*> field <*> field

135

151

152+instance (FromField a, FromField b, FromField c, FromField d) =>

153+ FromRow (Maybe (a,b,c,d)) where

154+ fromRow = (null *> null *> null *> null *> pure Nothing)

155+ <|> (Just <$> fromRow)

156+

136instance (FromField a, FromField b, FromField c, FromField d, FromField e) =>

157instance (FromField a, FromField b, FromField c, FromField d, FromField e) =>

137 FromRow (a,b,c,d,e) where

158 FromRow (a,b,c,d,e) where

138 fromRow = (,,,,) <$> field <*> field <*> field <*> field <*> field

159 fromRow = (,,,,) <$> field <*> field <*> field <*> field <*> field

139

160

161+instance (FromField a, FromField b, FromField c, FromField d, FromField e) =>

162+ FromRow (Maybe (a,b,c,d,e)) where

163+ fromRow = (null *> null *> null *> null *> null *> pure Nothing)

164+ <|> (Just <$> fromRow)

165+

140instance (FromField a, FromField b, FromField c, FromField d, FromField e,

166instance (FromField a, FromField b, FromField c, FromField d, FromField e,

141 FromField f) =>

167 FromField f) =>

142 FromRow (a,b,c,d,e,f) where

168 FromRow (a,b,c,d,e,f) where

143 fromRow = (,,,,,) <$> field <*> field <*> field <*> field <*> field

169 fromRow = (,,,,,) <$> field <*> field <*> field <*> field <*> field

144 <*> field

170 <*> field

145

171

172+instance (FromField a, FromField b, FromField c, FromField d, FromField e,

173+ FromField f) =>

174+ FromRow (Maybe (a,b,c,d,e,f)) where

175+ fromRow = (null *> null *> null *> null *> null *>

176+ null *> pure Nothing)

177+ <|> (Just <$> fromRow)

178+

146instance (FromField a, FromField b, FromField c, FromField d, FromField e,

179instance (FromField a, FromField b, FromField c, FromField d, FromField e,

147 FromField f, FromField g) =>

180 FromField f, FromField g) =>

148 FromRow (a,b,c,d,e,f,g) where

181 FromRow (a,b,c,d,e,f,g) where

149 fromRow = (,,,,,,) <$> field <*> field <*> field <*> field <*> field

182 fromRow = (,,,,,,) <$> field <*> field <*> field <*> field <*> field

150 <*> field <*> field

183 <*> field <*> field

151

184

185+instance (FromField a, FromField b, FromField c, FromField d, FromField e,

186+ FromField f, FromField g) =>

187+ FromRow (Maybe (a,b,c,d,e,f,g)) where

188+ fromRow = (null *> null *> null *> null *> null *>

189+ null *> null *> pure Nothing)

190+ <|> (Just <$> fromRow)

191+

152instance (FromField a, FromField b, FromField c, FromField d, FromField e,

192instance (FromField a, FromField b, FromField c, FromField d, FromField e,

153 FromField f, FromField g, FromField h) =>

193 FromField f, FromField g, FromField h) =>

154 FromRow (a,b,c,d,e,f,g,h) where

194 FromRow (a,b,c,d,e,f,g,h) where

155 fromRow = (,,,,,,,) <$> field <*> field <*> field <*> field <*> field

195 fromRow = (,,,,,,,) <$> field <*> field <*> field <*> field <*> field

156 <*> field <*> field <*> field

196 <*> field <*> field <*> field

157

197

198+instance (FromField a, FromField b, FromField c, FromField d, FromField e,

199+ FromField f, FromField g, FromField h) =>

200+ FromRow (Maybe (a,b,c,d,e,f,g,h)) where

201+ fromRow = (null *> null *> null *> null *> null *>

202+ null *> null *> null *> pure Nothing)

203+ <|> (Just <$> fromRow)

204+

158instance (FromField a, FromField b, FromField c, FromField d, FromField e,

205instance (FromField a, FromField b, FromField c, FromField d, FromField e,

159 FromField f, FromField g, FromField h, FromField i) =>

206 FromField f, FromField g, FromField h, FromField i) =>

160 FromRow (a,b,c,d,e,f,g,h,i) where

207 FromRow (a,b,c,d,e,f,g,h,i) where

161 fromRow = (,,,,,,,,) <$> field <*> field <*> field <*> field <*> field

208 fromRow = (,,,,,,,,) <$> field <*> field <*> field <*> field <*> field

162 <*> field <*> field <*> field <*> field

209 <*> field <*> field <*> field <*> field

163

210

211+instance (FromField a, FromField b, FromField c, FromField d, FromField e,

212+ FromField f, FromField g, FromField h, FromField i) =>

213+ FromRow (Maybe (a,b,c,d,e,f,g,h,i)) where

214+ fromRow = (null *> null *> null *> null *> null *>

215+ null *> null *> null *> null *> pure Nothing)

216+ <|> (Just <$> fromRow)

217+

164instance (FromField a, FromField b, FromField c, FromField d, FromField e,

218instance (FromField a, FromField b, FromField c, FromField d, FromField e,

165 FromField f, FromField g, FromField h, FromField i, FromField j) =>

219 FromField f, FromField g, FromField h, FromField i, FromField j) =>

166 FromRow (a,b,c,d,e,f,g,h,i,j) where

220 FromRow (a,b,c,d,e,f,g,h,i,j) where

167 fromRow = (,,,,,,,,,) <$> field <*> field <*> field <*> field <*> field

221 fromRow = (,,,,,,,,,) <$> field <*> field <*> field <*> field <*> field

168 <*> field <*> field <*> field <*> field <*> field

222 <*> field <*> field <*> field <*> field <*> field

169

223

224+instance (FromField a, FromField b, FromField c, FromField d, FromField e,

225+ FromField f, FromField g, FromField h, FromField i, FromField j) =>

226+ FromRow (Maybe (a,b,c,d,e,f,g,h,i,j)) where

227+ fromRow = (null *> null *> null *> null *> null *>

228+ null *> null *> null *> null *> null *> pure Nothing)

229+ <|> (Just <$> fromRow)

230+

170instance FromField a => FromRow [a] where

231instance FromField a => FromRow [a] where

171 fromRow = do

232 fromRow = do

172 n <- numFieldsRemaining

233 n <- numFieldsRemaining

173 replicateM n field

234 replicateM n field

174

235

236+instance FromField a => FromRow (Maybe [a]) where

237+ fromRow = do

238+ n <- numFieldsRemaining

239+ (replicateM_ n null *> pure Nothing) <|> (Just <$> replicateM n field)

240+

175instance FromField a => FromRow (Vector a) where

241instance FromField a => FromRow (Vector a) where

176 fromRow = do

242 fromRow = do

177 n <- numFieldsRemaining

243 n <- numFieldsRemaining

178 V.replicateM n field

244 V.replicateM n field

179

245

246+instance FromField a => FromRow (Maybe (Vector a)) where

247+ fromRow = do

248+ n <- numFieldsRemaining

249+ (replicateM_ n null *> pure Nothing) <|> (Just <$> V.replicateM n field)

250+

180instance (FromRow a, FromRow b) => FromRow (a :. b) where

251instance (FromRow a, FromRow b) => FromRow (a :. b) where

181 fromRow = (:.) <$> fromRow <*> fromRow

252 fromRow = (:.) <$> fromRow <*> fromRow