Frames.ColumnTypeable

Documentation

data Parsed a

Constructors

Possibly a

Definitely a

Instances

Functor Parsed

Methods

fmap :: (a -> b) -> Parsed a -> Parsed b

(<$) :: a -> Parsed b -> Parsed a

Eq a => Eq (Parsed a)

Methods

(==) :: Parsed a -> Parsed a -> Bool

(/=) :: Parsed a -> Parsed a -> Bool

Ord a => Ord (Parsed a)

Methods

compare :: Parsed a -> Parsed a -> Ordering

(<) :: Parsed a -> Parsed a -> Bool

(<=) :: Parsed a -> Parsed a -> Bool

(>) :: Parsed a -> Parsed a -> Bool

(>=) :: Parsed a -> Parsed a -> Bool

max :: Parsed a -> Parsed a -> Parsed a

min :: Parsed a -> Parsed a -> Parsed a

Show a => Show (Parsed a)

Methods

showsPrec :: Int -> Parsed a -> ShowS

show :: Parsed a -> String

showList :: [Parsed a] -> ShowS

class Parseable a where

Values that can be read from a Text with more or less discrimination.

Methods

parse :: MonadPlus m => Text -> m (Parsed a)

Returns Nothing if a value of the given type can not be read; returns 'Just Possibly' if a value can be read, but is likely ambiguous (e.g. an empty string); returns 'Just Definitely' if a value can be read and is unlikely to be ambiguous."

parse :: (Readable a, MonadPlus m) => Text -> m (Parsed a)

Returns Nothing if a value of the given type can not be read; returns 'Just Possibly' if a value can be read, but is likely ambiguous (e.g. an empty string); returns 'Just Definitely' if a value can be read and is unlikely to be ambiguous."

Instances

Parseable Bool

Methods

parse :: MonadPlus m => Text -> m (Parsed Bool)

Parseable Double

Methods

parse :: MonadPlus m => Text -> m (Parsed Double)

Parseable Float

Methods

parse :: MonadPlus m => Text -> m (Parsed Float)

Parseable Int

Methods

parse :: MonadPlus m => Text -> m (Parsed Int)

Parseable Text

Methods

parse :: MonadPlus m => Text -> m (Parsed Text)

discardConfidence :: Parsed a -> a

Discard any estimate of a parse's ambiguity.

parse' :: (MonadPlus m, Parseable a) => Text -> m a

Acts just like fromText: tries to parse a value from a Text and discards any estimate of the parse's ambiguity.

class ColumnTypeable a where

This class relates a universe of possible column types to Haskell types, and provides a mechanism to infer which type best represents some textual data.

Minimal complete definition

colType, inferType

Methods

colType :: a -> Q Type

inferType :: Text -> a