Safe Haskell	None
Language	Haskell2010

Mu.Schema.Interpretation.Schemaless

Contents

Terms without an associated schema
Checking and conversion against a schema
For deserialization to schemaless terms
For implementors

Description

In the edges of your application it's useful to consider terms for which a type-level schema has not yet been applied. Think of receiving a JSON document: you can parse it but checking the schema is an additional step.

Synopsis

data Term where
- TRecord :: [Field] -> Term
- TEnum :: Int -> Term
- TSimple :: FieldValue -> Term
data Field where
- Field :: Text -> FieldValue -> Field
data FieldValue where
- FNull :: FieldValue
- FPrimitive :: (Typeable t, Eq t, Ord t, Show t) => t -> FieldValue
- FSchematic :: Term -> FieldValue
- FOption :: Maybe FieldValue -> FieldValue
- FList :: [FieldValue] -> FieldValue
- FMap :: Map FieldValue FieldValue -> FieldValue
checkSchema :: forall tn fn (s :: Schema tn fn) (t :: tn). CheckSchema s (s :/: t) => Proxy t -> Term -> Maybe (Term s (s :/: t))
fromSchemalessTerm :: forall sch t sty. (FromSchema sch sty t, CheckSchema sch (sch :/: sty)) => Term -> Maybe t
class ToSchemalessTerm t where
- toSchemalessTerm :: t -> Term
class ToSchemalessValue t where
- toSchemalessValue :: t -> FieldValue
class CheckSchema (s :: Schema tn fn) (t :: TypeDef tn fn)

Terms without an associated schema

data Term where Source #

Interpretation of a type in a schema.

Constructors

TRecord :: [Field] -> Term	A record given by the value of its fields.
TEnum :: Int -> Term	An enumeration given by one choice.
TSimple :: FieldValue -> Term	A primitive value.

Instances

Eq Term Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods (==) :: Term -> Term -> Bool # (/=) :: Term -> Term -> Bool #
Ord Term Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods compare :: Term -> Term -> Ordering # (<) :: Term -> Term -> Bool # (<=) :: Term -> Term -> Bool # (>) :: Term -> Term -> Bool # (>=) :: Term -> Term -> Bool # max :: Term -> Term -> Term # min :: Term -> Term -> Term #
Show Term Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods showsPrec :: Int -> Term -> ShowS # show :: Term -> String # showList :: [Term] -> ShowS #

data Field where Source #

Interpretation of a field.

Constructors

Field :: Text -> FieldValue -> Field

A single field given by its name and its value.

Instances

Eq Field Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods (==) :: Field -> Field -> Bool # (/=) :: Field -> Field -> Bool #
Ord Field Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods compare :: Field -> Field -> Ordering # (<) :: Field -> Field -> Bool # (<=) :: Field -> Field -> Bool # (>) :: Field -> Field -> Bool # (>=) :: Field -> Field -> Bool # max :: Field -> Field -> Field # min :: Field -> Field -> Field #
Show Field Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods showsPrec :: Int -> Field -> ShowS # show :: Field -> String # showList :: [Field] -> ShowS #

data FieldValue where Source #

Interpretation of a field type, by giving a value of that type.

Constructors

FNull :: FieldValue
FPrimitive :: (Typeable t, Eq t, Ord t, Show t) => t -> FieldValue
FSchematic :: Term -> FieldValue
FOption :: Maybe FieldValue -> FieldValue
FList :: [FieldValue] -> FieldValue
FMap :: Map FieldValue FieldValue -> FieldValue

Instances

Eq FieldValue Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods (==) :: FieldValue -> FieldValue -> Bool # (/=) :: FieldValue -> FieldValue -> Bool #
Ord FieldValue Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods compare :: FieldValue -> FieldValue -> Ordering # (<) :: FieldValue -> FieldValue -> Bool # (<=) :: FieldValue -> FieldValue -> Bool # (>) :: FieldValue -> FieldValue -> Bool # (>=) :: FieldValue -> FieldValue -> Bool # max :: FieldValue -> FieldValue -> FieldValue # min :: FieldValue -> FieldValue -> FieldValue #
Show FieldValue Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods showsPrec :: Int -> FieldValue -> ShowS # show :: FieldValue -> String # showList :: [FieldValue] -> ShowS #

Checking and conversion against a schema

checkSchema :: forall tn fn (s :: Schema tn fn) (t :: tn). CheckSchema s (s :/: t) => Proxy t -> Term -> Maybe (Term s (s :/: t)) Source #

Checks that a schemaless Term obbeys the restrictions for tyoe t of schema s. If successful, returns a Term indexed by the corresponding schema and type.

Use this function to check a schemaless terms at the "borders" of your application.

fromSchemalessTerm :: forall sch t sty. (FromSchema sch sty t, CheckSchema sch (sch :/: sty)) => Term -> Maybe t Source #

Converts a schemaless term to a Haskell type by going through the corresponding schema type.

For deserialization to schemaless terms

class ToSchemalessTerm t where Source #

Deserialization to schemaless terms.

Methods

toSchemalessTerm :: t -> Term Source #

Turns a document (such as JSON) into a schemaless term. This function should handle the "compound" types in that format, such as records and enumerations.

Instances

ToSchemalessTerm Value Source #
Instance details Defined in Mu.Adapter.Json Methods toSchemalessTerm :: Value -> Term Source #

class ToSchemalessValue t where Source #

Deserialization to schemaless values.

Methods

toSchemalessValue :: t -> FieldValue Source #

Turns a document (such as JSON) into a schemaless term. This function should handle the "primitive" types in that format.

Instances

ToSchemalessValue Value Source #
Instance details Defined in Mu.Adapter.Json Methods toSchemalessValue :: Value -> FieldValue Source #

For implementors

class CheckSchema (s :: Schema tn fn) (t :: TypeDef tn fn) Source #

Type class used to define the generic checkSchema.

Exposed for usage in other modules, in particular Registry.

Minimal complete definition

checkSchema'

Instances

CheckSchemaValue s f => CheckSchema (s :: Schema typeName fn) (DSimple f :: TypeDefB Type typeName fn) Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods checkSchema' :: Term -> Maybe (Term s (DSimple f))
CheckSchemaFields s fields => CheckSchema (s :: Schema typeName fieldName) (DRecord nm fields :: TypeDefB Type typeName fieldName) Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods checkSchema' :: Term -> Maybe (Term s (DRecord nm fields))
CheckSchemaEnum choices => CheckSchema (s :: Schema tn fn) (DEnum nm choices :: TypeDefB Type tn fn) Source #
Instance details Defined in Mu.Schema.Interpretation.Schemaless Methods checkSchema' :: Term -> Maybe (Term s (DEnum nm choices))