applicative-extras-0.1.8: Instances for Applicative

Control.Applicative.Error

Synopsis

Documentation

data Failing a Source

An error idiom. Rather like the error monad, but collect all | errors together

Constructors

Success a 
Failure [ErrorMsg] 

Instances

type ErrorMsg = StringSource

maybeRead :: Read a => String -> Maybe aSource

maybeRead' :: Read a => String -> String -> Failing aSource

Tries to read a value. Shows an error message when reading fails.

asInteger :: String -> Failing IntegerSource

Tries to read an Integer

tryToEnum :: Enum a => Int -> Failing aSource

Tries conversion to an enum