Frames.ColumnTypeable

Documentation

data Parsed a

Constructors

Possibly a

Definitely a

Instances

Functor Parsed

Eq a => Eq (Parsed a)

Ord a => Ord (Parsed a)

Show a => Show (Parsed a)

class Parseable a where

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

Minimal complete definition

Nothing

Methods

parse :: (Functor m, 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

Parseable Double

Parseable Float

Parseable Int

Parseable Text

discardConfidence :: Parsed a -> a

Discard any estimate of a parse's ambiguity.

parse' :: (Functor m, 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.

Methods

colType :: a -> Q Type

inferType :: Text -> a