Data.Model.Util

Dependencies

Error utilities

type Errors = [Error]

A list of error messages

toErrors :: Bifunctor p => p a c -> p [a] c

noErrors :: Errors -> Bool

errsInContext :: (Convertible ctx String, Bifunctor p) => ctx -> p [String] c -> p [String] c

Prefix errors with a contextual note

inContext :: Convertible ctx String => ctx -> [String] -> [String]

Prefix a list of strings with a contextual note

>>> inContext "0/0" ["Zero denominator"]
["In 0/0: Zero denominator"]

errorToConvertResult :: (Typeable b, Typeable a, Show a) => (a -> Either Error b) -> a -> ConvertResult b

errorsToConvertResult :: (Typeable b, Typeable t, Show t) => (t -> Either Errors b) -> t -> ConvertResult b

>>> errorsToConvertResult (const (Left ["Bad format","Invalid value"])) ".." :: ConvertResult Int
Left (ConvertError {convSourceValue = "\"..\"", convSourceType = "[Char]", convDestType = "Int", convErrorMessage = "Bad format, Invalid value"})

convertResultToError :: Bifunctor p => p ConvertError c -> p String c

convertResultToErrors :: Bifunctor p => p ConvertError c -> p [String] c

convertOrError :: Convertible a c => a -> Either String c

>>> import Data.Word
>>> convertOrError 'a' :: Either Error Word
Right 97

>>> convertOrError (1E50::Double) :: Either Error Word64
Left "Convertible: error converting source data 1.0e50 of type Double to type Word64: Input value outside of bounds: (0,18446744073709551615)"

Convertible re-exports

class Convertible a b where

A typeclass that represents something that can be converted. A Convertible a b instance represents an a that can be converted to a b.

Methods

safeConvert :: a -> ConvertResult b

Convert a to b, returning Right on success and Left on error. For a simpler interface, see convert.

Instances

Convertible a a

Any type can be converted to itself.

Defined in Data.Convertible.Tiny

Methods

safeConvert :: a -> ConvertResult a

Convertible String QualName

Defined in Data.Model.Types

Methods

safeConvert :: String -> ConvertResult QualName

Convertible QualName String

Defined in Data.Model.Types

Methods

safeConvert :: QualName -> ConvertResult String

convert :: Convertible a b => a -> b

Convert from one type of data to another. Raises an exception if there is an error with the conversion. For a function that does not raise an exception in that case, see safeConvert.

type ConvertResult a = Either ConvertError a

The result of a safe conversion via safeConvert.

data ConvertError

How we indicate that there was an error.

Constructors

ConvertError

Fields

• convSourceValue :: String
• convSourceType :: String
• convDestType :: String
• convErrorMessage :: String

Instances

Eq ConvertError

Defined in Data.Convertible.Base

Methods

(==) :: ConvertError -> ConvertError -> Bool

(/=) :: ConvertError -> ConvertError -> Bool

Read ConvertError

Defined in Data.Convertible.Base

Methods

readsPrec :: Int -> ReadS ConvertError

readList :: ReadS [ConvertError]

readPrec :: ReadPrec ConvertError

readListPrec :: ReadPrec [ConvertError]

Show ConvertError

Defined in Data.Convertible.Base

Methods

showsPrec :: Int -> ConvertError -> ShowS

show :: ConvertError -> String

showList :: [ConvertError] -> ShowS

Error ConvertError

Defined in Data.Convertible.Base

Methods

noMsg :: ConvertError

strMsg :: String -> ConvertError

Formatting utilities

dotted :: [String] -> String

Intercalate a dot between the non empty elements of a list of strings.

>>> dotted []
""

>>> dotted ["","bc","de"]
"bc.de"

>>> dotted ["bc","","de"]
"bc.de"