Copyright	(c) Ole Krüger 2016
License	BSD3
Maintainer	Ole Krüger <ole@vprsm.de>
Safe Haskell	None
Language	Haskell2010

Database.PostgreSQL.Store.RowParser

Contents

Row parser
Means of composition
Default parsers

Description

Synopsis

Row parser

data RowParser w a Source #

Consumes w columns of a result set row in order to produce an instance of a.

Instances

Functor (RowParser w) Source #
Methods fmap :: (a -> b) -> RowParser w a -> RowParser w b # (<$) :: a -> RowParser w b -> RowParser w a #

data RowErrorLocation Source #

Location of an error

Constructors

RowErrorLocation Column Row

Instances

Eq RowErrorLocation Source #
Methods (==) :: RowErrorLocation -> RowErrorLocation -> Bool # (/=) :: RowErrorLocation -> RowErrorLocation -> Bool #
Ord RowErrorLocation Source #
Methods compare :: RowErrorLocation -> RowErrorLocation -> Ordering # (<) :: RowErrorLocation -> RowErrorLocation -> Bool # (<=) :: RowErrorLocation -> RowErrorLocation -> Bool # (>) :: RowErrorLocation -> RowErrorLocation -> Bool # (>=) :: RowErrorLocation -> RowErrorLocation -> Bool # max :: RowErrorLocation -> RowErrorLocation -> RowErrorLocation # min :: RowErrorLocation -> RowErrorLocation -> RowErrorLocation #
Show RowErrorLocation Source #
Methods showsPrec :: Int -> RowErrorLocation -> ShowS # show :: RowErrorLocation -> String # showList :: [RowErrorLocation] -> ShowS #

data RowErrorDetail Source #

Errors that occur during row parsing

Constructors

TooFewColumns	Underlying `RowParser` wants more columns than are currently present.
ColumnRejected	A column value could not be parsed.

Instances

Eq RowErrorDetail Source #
Methods (==) :: RowErrorDetail -> RowErrorDetail -> Bool # (/=) :: RowErrorDetail -> RowErrorDetail -> Bool #
Ord RowErrorDetail Source #
Methods compare :: RowErrorDetail -> RowErrorDetail -> Ordering # (<) :: RowErrorDetail -> RowErrorDetail -> Bool # (<=) :: RowErrorDetail -> RowErrorDetail -> Bool # (>) :: RowErrorDetail -> RowErrorDetail -> Bool # (>=) :: RowErrorDetail -> RowErrorDetail -> Bool # max :: RowErrorDetail -> RowErrorDetail -> RowErrorDetail # min :: RowErrorDetail -> RowErrorDetail -> RowErrorDetail #
Show RowErrorDetail Source #
Methods showsPrec :: Int -> RowErrorDetail -> ShowS # show :: RowErrorDetail -> String # showList :: [RowErrorDetail] -> ShowS #

data RowError Source #

An error that occured when parsing a row

Constructors

RowError RowErrorLocation RowErrorDetail

Instances

Eq RowError Source #
Methods (==) :: RowError -> RowError -> Bool # (/=) :: RowError -> RowError -> Bool #
Ord RowError Source #
Methods compare :: RowError -> RowError -> Ordering # (<) :: RowError -> RowError -> Bool # (<=) :: RowError -> RowError -> Bool # (>) :: RowError -> RowError -> Bool # (>=) :: RowError -> RowError -> Bool # max :: RowError -> RowError -> RowError # min :: RowError -> RowError -> RowError #
Show RowError Source #
Methods showsPrec :: Int -> RowError -> ShowS # show :: RowError -> String # showList :: [RowError] -> ShowS #

processResultWith :: forall a n. KnownNat n => Result -> RowParser n a -> ExceptT RowError IO [a] Source #

Process the each row of the Result with the given RowParser.

Means of composition

(>>=$) :: forall a v b w. KnownNat v => RowParser v a -> (a -> RowParser w b) -> RowParser (v + w) b infixl 1 Source #

Transform the result of another RowParser. Similar to monadic bind. Also keeps track of how many columns are needed in total.

(>>$) :: forall a v b w. KnownNat v => RowParser v a -> RowParser w b -> RowParser (v + w) b infixl 1 Source #

Chain two RowParsers, but discard the result of the first.

(<*>$) :: forall a v b w. KnownNat v => RowParser v (a -> b) -> RowParser w a -> RowParser (v + w) b infixl 4 Source #

Just like the '(*)' operator.

finish :: a -> RowParser 0 a Source #

Terminate the parsing tree by returning the final result.

cancel :: RowErrorDetail -> RowParser 0 a Source #

Terminate the parsing tree with an error.

skipColumns :: RowParser n () Source #

Skip a number of columns.

nonNullCheck :: Int -> RowParser 0 Bool Source #

Check if the following n columns are not NULL.

Default parsers

processContent :: (Oid -> Maybe ByteString -> Maybe a) -> RowParser 1 a Source #

Process the contents of a column.

retrieveColumn :: RowParser 1 (Oid, Maybe ByteString) Source #

Retrieve a column's type and content.

retrieveContent :: RowParser 1 ByteString Source #

Retrieve a column's content.