Rerefined.Predicate.Common

Handy utilities for defining predicates.

Re-exports

module Rerefined.Predicate

proxy# :: forall {k} (a :: k). Proxy# a

Witness for an unboxed Proxy# value, which has no runtime representation.

data Builder

Thin wrapper over Buffer with a handy Semigroup instance.

>>> :set -XOverloadedStrings -XMagicHash
>>> fromText "foo" <> fromChar '_' <> fromAddr "bar"#
"foo_bar"

Remember: this is a strict builder, so on contrary to Data.Text.Lazy.Builder for optimal performance you should use strict left folds instead of lazy right ones.

Note that (similar to other builders) concatenation of Builders allocates thunks. This is to a certain extent mitigated by aggressive inlining, but it is faster to use Buffer directly.

Instances

IsString Builder

Defined in Data.Text.Builder.Linear

Methods

fromString :: String -> Builder

Monoid Builder

Defined in Data.Text.Builder.Linear

Methods

mempty :: Builder

mappend :: Builder -> Builder -> Builder

mconcat :: [Builder] -> Builder

Semigroup Builder

Defined in Data.Text.Builder.Linear

Methods

(<>) :: Builder -> Builder -> Builder

sconcat :: NonEmpty Builder -> Builder

stimes :: Integral b => b -> Builder -> Builder

Show Builder

Defined in Data.Text.Builder.Linear

Methods

showsPrec :: Int -> Builder -> ShowS

show :: Builder -> String

showList :: [Builder] -> ShowS

class IsString a

IsString is used in combination with the -XOverloadedStrings language extension to convert the literals to different string types.

For example, if you use the text package, you can say

{-# LANGUAGE OverloadedStrings  #-}

myText = "hello world" :: Text

Internally, the extension will convert this to the equivalent of

myText = fromString @Text ("hello world" :: String)

Note: You can use fromString in normal code as well, but the usual performance/memory efficiency problems with String apply.

Minimal complete definition

fromString

Instances

IsString ByteString

Beware: fromString truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�

Defined in Data.ByteString.Internal.Type

Methods

fromString :: String -> ByteString

IsString ByteString

Beware: fromString truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�

Defined in Data.ByteString.Lazy.Internal

Methods

fromString :: String -> ByteString

IsString ShortByteString

Beware: fromString truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�

Defined in Data.ByteString.Short.Internal

Methods

fromString :: String -> ShortByteString

IsString Doc

Defined in Text.PrettyPrint.HughesPJ

Methods

fromString :: String -> Doc

IsString Builder

Defined in Data.Text.Builder.Linear

Methods

fromString :: String -> Builder

IsString a => IsString (Identity a)

Since: base-4.9.0.0

Defined in Data.String

Methods

fromString :: String -> Identity a

a ~ Char => IsString (Seq a)

Since: containers-0.5.7

Defined in Data.Sequence.Internal

Methods

fromString :: String -> Seq a

(IsString a, Hashable a) => IsString (Hashed a)

Defined in Data.Hashable.Class

Methods

fromString :: String -> Hashed a

IsString (Doc a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fromString :: String -> Doc a

a ~ Char => IsString [a]

(a ~ Char) context was introduced in 4.9.0.0

Since: base-2.1

Defined in Data.String

Methods

fromString :: String -> [a]

IsString a => IsString (Const a b)

Since: base-4.9.0.0

Defined in Data.String

Methods

fromString :: String -> Const a b

Predicate validation

validateFail :: forall p. (Predicate p, KnownPredicateName p) => Proxy# p -> Builder -> [RefineFailure] -> Maybe RefineFailure

Shortcut for returning a predicate validation failure.

validateBool :: forall p. (Predicate p, KnownPredicateName p) => Proxy# p -> Builder -> Bool -> Maybe RefineFailure

Shortcut for simply validating a Bool.

type KnownPredicateName p = KnownSymbol (PredicateName 0 p)