Toml.Schema.FromValue

Use FromValue to define a transformation from some Value to an application domain type.

Use ParseTable to help build FromValue instances that match tables. It will make it easy to track which table keys have been used and which are left over.

Warnings can be emitted using warn and warnTable (depending on what) context you're in. These warnings can provide useful feedback about problematic values or keys that might be unused now but were perhaps meaningful in an old version of a configuration file.

Toml.Schema.FromValue.Generic can be used to derive instances of FromValue automatically for record types.

Deserialization classes

class FromValue a where

Class for types that can be decoded from a TOML value.

Minimal complete definition

fromValue

Methods

fromValue :: Value' l -> Matcher l a

Convert a Value or report an error message

listFromValue :: Value' l -> Matcher l [a]

Used to implement instance for []. Most implementations rely on the default implementation.

Instances

FromValue Int16

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Int16

listFromValue :: Value' l -> Matcher l [Int16]

FromValue Int32

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Int32

listFromValue :: Value' l -> Matcher l [Int32]

FromValue Int64

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Int64

listFromValue :: Value' l -> Matcher l [Int64]

FromValue Int8

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Int8

listFromValue :: Value' l -> Matcher l [Int8]

FromValue Word16

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Word16

listFromValue :: Value' l -> Matcher l [Word16]

FromValue Word32

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Word32

listFromValue :: Value' l -> Matcher l [Word32]

FromValue Word64

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Word64

listFromValue :: Value' l -> Matcher l [Word64]

FromValue Word8

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Word8

listFromValue :: Value' l -> Matcher l [Word8]

FromValue Text

Matches string literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Text

listFromValue :: Value' l -> Matcher l [Text]

FromValue Text

Matches string literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Text

listFromValue :: Value' l -> Matcher l [Text]

FromValue Day

Matches local date literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Day

listFromValue :: Value' l -> Matcher l [Day]

FromValue UTCTime

Matches offset date-time literals and converts to UTC

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l UTCTime

listFromValue :: Value' l -> Matcher l [UTCTime]

FromValue LocalTime

Matches local date-time literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l LocalTime

listFromValue :: Value' l -> Matcher l [LocalTime]

FromValue TimeOfDay

Matches local time literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l TimeOfDay

listFromValue :: Value' l -> Matcher l [TimeOfDay]

FromValue ZonedTime

Matches offset date-time literals

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l ZonedTime

listFromValue :: Value' l -> Matcher l [ZonedTime]

FromValue Table

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Table

listFromValue :: Value' l -> Matcher l [Table]

FromValue Value

Matches all values, used for pass-through

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Value

listFromValue :: Value' l -> Matcher l [Value]

FromValue Integer

Matches integer values

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Integer

listFromValue :: Value' l -> Matcher l [Integer]

FromValue Natural

Matches non-negative integer values

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Natural

listFromValue :: Value' l -> Matcher l [Natural]

FromValue Bool

Matches true and false

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Bool

listFromValue :: Value' l -> Matcher l [Bool]

FromValue Char

Matches single-character strings with fromValue and arbitrary strings with listFromValue to support String

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Char

listFromValue :: Value' l -> Matcher l [Char]

FromValue Double

Matches floating-point and integer values

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Double

listFromValue :: Value' l -> Matcher l [Double]

FromValue Float

Matches floating-point and integer values

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Float

listFromValue :: Value' l -> Matcher l [Float]

FromValue Int

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Int

listFromValue :: Value' l -> Matcher l [Int]

FromValue Word

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l Word

listFromValue :: Value' l -> Matcher l [Word]

FromValue a => FromValue (NonEmpty a)

Matches non-empty arrays or reports an error.

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l (NonEmpty a)

listFromValue :: Value' l -> Matcher l [NonEmpty a]

Integral a => FromValue (Ratio a)

Matches floating-point and integer values.

TOML specifies Floats should be implemented as IEEE 754 binary64 values. so note that the given Rational will be converted from a double representation and will often be an approximation rather than the exact value.

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l (Ratio a)

listFromValue :: Value' l -> Matcher l [Ratio a]

FromValue a => FromValue (Seq a)

Matches arrays

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l (Seq a)

listFromValue :: Value' l -> Matcher l [Seq a]

(Generic a, GFromArray (Rep a)) => FromValue (GenericTomlArray a)

Instance derived using genericFromArray

Defined in Toml.Schema.Generic

Methods

fromValue :: Value' l -> Matcher l (GenericTomlArray a)

listFromValue :: Value' l -> Matcher l [GenericTomlArray a]

(Generic a, GParseTable (Rep a)) => FromValue (GenericTomlTable a)

Instance derived using genericParseTable

Defined in Toml.Schema.Generic

Methods

fromValue :: Value' l -> Matcher l (GenericTomlTable a)

listFromValue :: Value' l -> Matcher l [GenericTomlTable a]

FromValue a => FromValue [a]

Implemented in terms of listFromValue

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l [a]

listFromValue :: Value' l -> Matcher l [[a]]

(Ord k, FromKey k, FromValue v) => FromValue (Map k v)

Defined in Toml.Schema.FromValue

Methods

fromValue :: Value' l -> Matcher l (Map k v)

listFromValue :: Value' l -> Matcher l [Map k v]

class FromKey a where

Convert from a table key

Methods

fromKey :: l -> Text -> Matcher l a

Instances

FromKey Text

Matches all strings

Defined in Toml.Schema.FromValue

Methods

fromKey :: l -> Text -> Matcher l Text

FromKey Text

Matches all strings

Defined in Toml.Schema.FromValue

Methods

fromKey :: l -> Text0 -> Matcher l Text

a ~ Char => FromKey [a]

Matches all strings

Defined in Toml.Schema.FromValue

Methods

fromKey :: l -> Text -> Matcher l [a]

Containers

mapOf

Arguments

:: Ord k

=> (l -> Text -> Matcher l k)

key matcher

-> (Text -> Value' l -> Matcher l v)

value matcher

-> Value' l

-> Matcher l (Map k v)

Table matching function used to help implement fromValue for tables. Key matching function is given the annotation of the key for error reporting. Value matching function is given the key in case values can depend on their keys.

listOf :: (Int -> Value' l -> Matcher l a) -> Value' l -> Matcher l [a]

List matching function used to help implemented fromValue for arrays. The element matching function is given the list index in case values can depend on their index.

Tables

parseTableFromValue :: ParseTable l a -> Value' l -> Matcher l a

Used to derive a fromValue implementation from a ParseTable matcher.

reqKey :: FromValue a => Text -> ParseTable l a

Convenience function for matching a required key with a FromValue instance.

reqKey key = reqKeyOf key fromValue

reqKeyOf

Arguments

:: Text

key

-> (Value' l -> Matcher l a)

value matcher

-> ParseTable l a

Match a table entry by key or report an error if missing.

See pickKey for more complex cases.

optKey :: FromValue a => Text -> ParseTable l (Maybe a)

Convenience function for matching an optional key with a FromValue instance.

optKey key = optKeyOf key fromValue

optKeyOf

Arguments

:: Text

key

-> (Value' l -> Matcher l a)

value matcher

-> ParseTable l (Maybe a)

Match a table entry by key if it exists or return Nothing if not. If the key is defined, it is matched by the given function.

See pickKey for more complex cases.

Errors

typeError

Arguments

:: String

expected type

-> Value' l

actual value

-> Matcher l a

Report a type error