Moduletoml-parser-2.0.0.0Haskell2010

Toml.Schema.Matcher

This type helps to build up computations that can validate a TOML value and compute some application-specific representation.

It supports warning messages which can be used to deprecate old configuration options and to detect unused table keys.

It supports tracking multiple error messages when you have more than one decoding option and all of them have failed.

Use Toml.Pretty.prettyMatchMessage for an easy way to make human readable strings from matcher outputs.

4 types
10 values

Packagetoml-parser-2.0.0.0
Exports14
LanguageHaskell2010
LicenceISC
SourceMatcher.hs

Types

3 declarations

newtypenewtype Matcher l a

Computations that result in a Result and which track a list of nested contexts to assist in generating warnings and error messages.

Use withScope to run a Matcher in a new, nested scope.

Instances6Monad, Functor, MonadFail, Applicative, Alternative, MonadPlus

Monad (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Functor (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
MonadFail (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Fail with an error message without an annotation.
Applicative (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Alternative (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
MonadPlus (Matcher a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher

datadata Result e a

Computation outcome with error and warning messages. Multiple error messages can occur when multiple alternatives all fail. Resolving any one of the error messages could allow the computation to succeed.

Constructors

Failure [e]
error messages
Success [e] a
warning messages and result

Instances4Eq, Ord, Read, Show

(Eq e, Eq a) => Eq (Result e a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
(Ord e, Ord a) => Ord (Result e a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
(Read e, Read a) => Read (Result e a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
(Show e, Show a) => Show (Result e a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance

datadata MatchMessage a

A message emitted while matching a TOML value. The message is paired with the path to the value that was in focus when the message was generated. These message get used for both warnings and errors.

For a convenient way to render these to a string, see Toml.Pretty.prettyMatchMessage.

Constructors

MatchMessage
- matchAnn :: Maybe a
- matchPath :: [Scope]
  path to message location
- matchMessage :: String
  error and warning message body

Instances7Functor, Foldable, Traversable, Eq, Ord, Read, …

Functor MatchMessageDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Foldable MatchMessageDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Traversable MatchMessageDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Eq a => Eq (MatchMessage a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Ord a => Ord (MatchMessage a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Read a => Read (MatchMessage a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Show a => Show (MatchMessage a)Defined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance

Operations

6 declarations

valuerunMatcher :: Matcher l a -> Result (MatchMessage l) a

Run a Matcher with an empty scope.

valuewithScope :: Scope -> Matcher l a -> Matcher l a

Run a Matcher with a locally extended scope.

valuegetScope :: Matcher a [Scope]

Get the current list of scopes.

valuewarn :: String -> Matcher a ()

Emit a warning without an annotation.

valuewarnAt :: l -> String -> Matcher l ()

Emit a warning mentioning the given annotation.

valuefailAt :: l -> String -> Matcher l a

Terminate the match with an error mentioning the given annotation.

Run helpers

2 declarations

valuerunMatcherIgnoreWarn :: Matcher l a -> Either [MatchMessage l] a

Run Matcher and ignore warnings.

valuerunMatcherFatalWarn :: Matcher l a -> Either [MatchMessage l] a

Run Matcher and treat warnings as errors.

Scope helpers

3 declarations

datadata Scope

Scopes for TOML message.

Constructors

ScopeIndex Int
zero-based array index
ScopeKey Text
key in a table

Instances4Eq, Ord, Read, Show

Eq ScopeDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Ord ScopeDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Read ScopeDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance
Show ScopeDefined in toml-parser-2.0.0.0 · Toml.Schema.Matcher
Default instance

valueinKey :: Text -> Matcher l a -> Matcher l a

Update the scope with the message corresponding to a table key

valueinIndex :: Int -> Matcher l a -> Matcher l a

Update the scope with the message corresponding to an array index