Data.Error.Tree

Documentation

newtype ErrorTree

A tree of Errors, with a single root Error and 0..n nested ErrorTrees.

top error
|
|-- error 1
| |
|  -- error 1.1
|
|-- error 2

Constructors

ErrorTree

Fields

• unErrorTree :: Tree Error

Instances

IsString ErrorTree

Defined in Data.Error.Tree

Methods

fromString :: String -> ErrorTree

Show ErrorTree

Defined in Data.Error.Tree

Methods

showsPrec :: Int -> ErrorTree -> ShowS

show :: ErrorTree -> String

showList :: [ErrorTree] -> ShowS

singleError :: Error -> ErrorTree

Turn a single Error into an ErrorTree, a leaf.

errorTree :: Error -> NonEmpty Error -> ErrorTree

Take a list of errors & create a new ErrorTree with the given Error as the root.

errorTreeContext :: Text -> ErrorTree -> ErrorTree

Attach more context to the root Error of the ErrorTree, via errorContext.

nestedError :: Error -> ErrorTree -> ErrorTree

Nest the given Error around the ErrorTree

top level error
|
-- nestedError
  |
  -- error 1
  |
  -- error 2

nestedMultiError :: Error -> NonEmpty ErrorTree -> ErrorTree

Nest the given Error around the list of ErrorTrees.

top level error
|
|- nestedError1
| |
| -- error 1
| |
| -- error 2
|
|- nestedError 2

prettyErrorTree :: ErrorTree -> Text

prettyErrorTrees :: NonEmpty ErrorTree -> Text

restrictErrorTree :: (HasField "maxlength" dat Natural, HasField "maxdepth" dat Natural) => dat -> ErrorTree -> ErrorTree

Sometimes, ErrorTrees can get very large. In that case, it’s recommended to first think about whether you can e.g. chunk the validation logic.

But even so, restricting the size of the ErrorTree before printing it is often a good idea.

This will make sure the given maxlength and maxdepth are not exceeded, and insert warnings if some subtree was elided.