1bda1d8 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

Documentation tweaks

commit1bda1d8b7ef32a01b073138647bd21fa014f58de authorLeon P Smith <leon@melding-monads.com> dateFri 4 May 2012, 19:12 (14 years ago) parent7921281

2 files changed+30−25

compare with master

unifiedsplit

CHANGES+18−18 src/Database/PostgreSQL/Simple.hs+12−7

CHANGES+18−18

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

1−Version 0.1:

1+Version 0.1: (2012-05-04)

22 * Renamed several modules, typeclasses, and functions:

44 QueryParams (renderParams) -> ToRow (toRow)

@@ -6,19 +6,19 @@ Version 0.1:

66 Param (render) -> ToField (toField)

77 Result (convert) -> FromField (fromField)

9− * Added the Database.PostgreSQL.Simple.Ok module

10−

9+ * Added the `Database.PostgreSQL.Simple.Ok` module, a variation of

10+ `Either SomeException` that has an instance for `Alternative` and also

11+ uses a list of exceptions to track the ways it has failed.

12+

1113 * Changed the return type of `fromField` and `fromRow` from

12− `Either SomeException` to `Ok`. Either doesn't have an instance for

13− Alternative, and an orphaned instance inside of postgresql-simple is a

14− very bad idea. Also, Ok returns a list of Exceptions so that you can

15− see all the ways it has failed.

16−

17− * Thanks to Ozgun Ataman, the "FromRow" typeclass has been massively

18− improved. The result is simpler definitions and better compositionality.

19− Also, user-defined instances need not be to be concerned about forcing

20− the converted results, as

21−

14+ `Either SomeException` to `Ok`.

15+

16+ * Thanks to suggestions from Ozgun Ataman, the `FromRow` typeclass has been

17+ massively improved. The result is simpler definitions and better

18+ compositionality. Also, user-defined instances need not be to be

19+ concerned about forcing the converted results to WHNF. Here is an

20+ example comparing the old to the new:

21+

2222 instance (Result a, Result b) => QueryResults (a,b) where

2323 convertResults [fa,fb] [va,vb] = do

2424 !a <- convert fa va

@@ -29,14 +29,14 @@ Version 0.1:

2929 instance (FromField a, FromField b) => FromRow (a,b) where

3030 fromRow = (,) <$> field <*> field

3131

32− * Added :., a pair that allows one to compose "FromRow" instances:

33−

32+ * Added `(:.)`, a pair that allows one to compose `FromRow` instances:

33+

3434 instance (FromRow a, FromRow b) => FromRow (a :. b) where

3535 fromRow = (:.) <$> fromRow <*> fromRow

3636

37− * Moved the contents Field module into the "FromField" module.

37+ * Moved the contents `Field` module into the `FromField` module.

3838

3939 * Removed the `RawResult` type.

4040

41− * Added `DefaultIsolationLevel` as a distinct `IsolationLevel` option and

42− `DefaultReadWriteMode as a distinct `ReadWriteMode` option.

41+ * Added `DefaultIsolationLevel` as a distinct `IsolationLevel` option

42+ and `DefaultReadWriteMode` as a distinct `ReadWriteMode`.

src/Database/PostgreSQL/Simple.hs+12−7

@@ -504,23 +504,28 @@ ellipsis bs

504504-- | Of the four isolation levels defined by the SQL standard,

505505-- these are the three levels distinguished by PostgreSQL as of version 9.0.

506506-- See <http://www.postgresql.org/docs/9.1/static/transaction-iso.html>

507−-- for more information.

507+-- for more information. Note that prior to PostgreSQL 9.0, 'RepeatableRead'

508+-- was equivalent to 'Serializable'.

508509

509510data IsolationLevel

510511 = DefaultIsolationLevel -- ^ the isolation level will be taken from

511512 -- PostgreSQL's per-connection

512− -- @default_transaction_isolation@ variable.

513+ -- @default_transaction_isolation@ variable,

514+ -- which is initialized according to the

515+ -- server's config. The default configuration

516+ -- is 'ReadCommitted'.

513517 | ReadCommitted

514518 | RepeatableRead

515− | Serializable -- ^ Note that prior to PostgreSQL 9.0,

516− -- @Serializable@ was equivalent to

517− -- @RepeatableRead@.

519+ | Serializable

518520 deriving (Show, Eq, Ord, Enum, Bounded)

519521

520522data ReadWriteMode

521− = DefaultReadWriteMode -- ^ the isolation level will be taken from the

523+ = DefaultReadWriteMode -- ^ the read-write mode will be taken from

522524 -- PostgreSQL's per-connection

523− -- @default_transaction_read_only@ variable.

525+ -- @default_transaction_read_only@ variable,

526+ -- which is initialized according to the

527+ -- server's config. The default configuration

528+ -- is 'ReadWrite'.

524529 | ReadWrite

525530 | ReadOnly

526531 deriving (Show, Eq, Ord, Enum, Bounded)