Data.StaticText

static-text combinators are defined for members of IsStaticText class. The package includes IsStaticText instances for several common types.

This module is meant to be imported qualifed, e.g.

import qualified Data.StaticText as S

Constructing static texts

See also unsafeCreate

create :: forall a i. (IsStaticText a, KnownNat i) => a -> Maybe (Static a i)

Safely create a Static if it matches target length.

>>> create "foobar" :: Maybe (Static String 6)
Just "foobar"
>>> create "barbaz" :: Maybe (Static String 8)
Nothing

This is safer than unsafeCreate and unlike with createLeft / createRight the source value is left unchanged. However, this implies a further run-time check for Nothing values.

createLeft :: forall a i. (IsStaticText a, KnownNat i) => Elem a -> a -> Static a i

Safely create a Static, possibly altering the source to match target length. If target length is less than that of the source, the source gets truncated. If target length is greater, the source is padded using the provided basic element. Elements on the left are preferred.

>>> createLeft ' ' "foobarbaz" :: Static String 6
"foobar"
>>> createLeft '#' "foobarbaz" :: Static String 12
"foobarbaz###"

createRight :: forall a i. (IsStaticText a, KnownNat i) => Elem a -> a -> Static a i

Just like createLeft, except that elements on the right are preferred.

>>> createRight '@' "foobarbaz" :: Static String 6
"barbaz"
>>> createRight '!' "foobarbaz" :: Static String 12
"!!!foobarbaz"

st :: LitS -> Q Exp

Type-safe Static constructor macro for string literals.

Example:

$(st "Foobar")

compiles to

unsafeCreate "Foobar" :: forall a. (IsString a, IsStaticText a) => Static a 6

where 6 is the string length obtained at compile time.

replicate :: forall a i. (IsStaticText a, KnownNat i) => Elem a -> Static a i

Construct a new Static from a basic element.

>>> replicate '=' :: Static String 10
"=========="

Working with static texts

append :: forall a m n. IsStaticText a => Static a m -> Static a n -> Static a (m + n)

Append two Statics together.

>>> append $(st "foo") $(st "bar") :: Static String 6
"foobar"

take :: forall a m n. (IsStaticText a, KnownNat m, KnownNat n, n <= m) => Static a m -> Static a n

Reduce Static length, preferring elements on the left.

>>> take $(st "Foobar") :: Static String 3
"Foo"

drop :: forall a m n. (IsStaticText a, KnownNat m, KnownNat n, n <= m) => Static a m -> Static a n

Reduce Static length, preferring elements on the right.

>>> drop $(st "Foobar") :: Static String 2
"ar"

map :: IsStaticText a => (Elem a -> Elem a) -> Static a m -> Static a m

Map a Static to a Static of the same length.

>>> map toUpper $(st "Hello") :: Static String 5
"HELLO"

padLeft :: forall a m n. (IsStaticText a, KnownNat m, KnownNat (n - m), n ~ ((n - m) + m), m <= n) => Elem a -> Static a m -> Static a n

Fill a Static with extra elements up to target length, padding original elements to the left.

padRight :: forall a m n. (IsStaticText a, KnownNat m, KnownNat (n - m), n ~ (m + (n - m)), m <= n) => Elem a -> Static a m -> Static a n

Like padLeft, but original elements are padded to the right.

length :: forall a m. KnownNat m => Static a m -> Int

Obtain value-level length.

IsStaticText class

data family Static a (i :: Nat)

Data family which wraps values of the underlying type giving them a type-level length. Static t 6 means a value of type t of length 6.

Instances

Eq a => Eq (Static [a] i)

Defined in Data.StaticText.Class

Methods

(==) :: Static [a] i -> Static [a] i -> Bool

(/=) :: Static [a] i -> Static [a] i -> Bool

Eq (Static ShortByteString i)

Defined in Data.StaticText.Class

Methods

(==) :: Static ShortByteString i -> Static ShortByteString i -> Bool

(/=) :: Static ShortByteString i -> Static ShortByteString i -> Bool

Eq (Static ByteString i)

Defined in Data.StaticText.Class

Methods

(==) :: Static ByteString i -> Static ByteString i -> Bool

(/=) :: Static ByteString i -> Static ByteString i -> Bool

Eq (Static Text i)

Defined in Data.StaticText.Class

Methods

(==) :: Static Text i -> Static Text i -> Bool

(/=) :: Static Text i -> Static Text i -> Bool

Eq a => Eq (Static (Vector a) i)

Defined in Data.StaticText.Class

Methods

(==) :: Static (Vector a) i -> Static (Vector a) i -> Bool

(/=) :: Static (Vector a) i -> Static (Vector a) i -> Bool

Ord a => Ord (Static [a] i)

Defined in Data.StaticText.Class

Methods

compare :: Static [a] i -> Static [a] i -> Ordering

(<) :: Static [a] i -> Static [a] i -> Bool

(<=) :: Static [a] i -> Static [a] i -> Bool

(>) :: Static [a] i -> Static [a] i -> Bool

(>=) :: Static [a] i -> Static [a] i -> Bool

max :: Static [a] i -> Static [a] i -> Static [a] i

min :: Static [a] i -> Static [a] i -> Static [a] i

Ord (Static ShortByteString i)

Defined in Data.StaticText.Class

Methods

compare :: Static ShortByteString i -> Static ShortByteString i -> Ordering

(<) :: Static ShortByteString i -> Static ShortByteString i -> Bool

(<=) :: Static ShortByteString i -> Static ShortByteString i -> Bool

(>) :: Static ShortByteString i -> Static ShortByteString i -> Bool

(>=) :: Static ShortByteString i -> Static ShortByteString i -> Bool

max :: Static ShortByteString i -> Static ShortByteString i -> Static ShortByteString i

min :: Static ShortByteString i -> Static ShortByteString i -> Static ShortByteString i

Ord (Static ByteString i)

Defined in Data.StaticText.Class

Methods

compare :: Static ByteString i -> Static ByteString i -> Ordering

(<) :: Static ByteString i -> Static ByteString i -> Bool

(<=) :: Static ByteString i -> Static ByteString i -> Bool

(>) :: Static ByteString i -> Static ByteString i -> Bool

(>=) :: Static ByteString i -> Static ByteString i -> Bool

max :: Static ByteString i -> Static ByteString i -> Static ByteString i

min :: Static ByteString i -> Static ByteString i -> Static ByteString i

Ord (Static Text i)

Defined in Data.StaticText.Class

Methods

compare :: Static Text i -> Static Text i -> Ordering

(<) :: Static Text i -> Static Text i -> Bool

(<=) :: Static Text i -> Static Text i -> Bool

(>) :: Static Text i -> Static Text i -> Bool

(>=) :: Static Text i -> Static Text i -> Bool

max :: Static Text i -> Static Text i -> Static Text i

min :: Static Text i -> Static Text i -> Static Text i

Ord a => Ord (Static (Vector a) i)

Defined in Data.StaticText.Class

Methods

compare :: Static (Vector a) i -> Static (Vector a) i -> Ordering

(<) :: Static (Vector a) i -> Static (Vector a) i -> Bool

(<=) :: Static (Vector a) i -> Static (Vector a) i -> Bool

(>) :: Static (Vector a) i -> Static (Vector a) i -> Bool

(>=) :: Static (Vector a) i -> Static (Vector a) i -> Bool

max :: Static (Vector a) i -> Static (Vector a) i -> Static (Vector a) i

min :: Static (Vector a) i -> Static (Vector a) i -> Static (Vector a) i

(Show a, IsStaticText a) => Show (Static a i)

Defined in Data.StaticText.Class

Methods

showsPrec :: Int -> Static a i -> ShowS

show :: Static a i -> String

showList :: [Static a i] -> ShowS

data Static ShortByteString i

Defined in Data.StaticText.Class

data Static ShortByteString i = ByteStringS ShortByteString

data Static ByteString i

Defined in Data.StaticText.Class

data Static ByteString i = ByteString ByteString

data Static Text i

Defined in Data.StaticText.Class

data Static Text i = Text Text

data Static [a] i

Defined in Data.StaticText.Class

data Static [a] i = List [a]

data Static (Vector a) i

Defined in Data.StaticText.Class

data Static (Vector a) i = Vector (Vector a)

class IsStaticText a where

Class of types which can be assigned a type-level length.

Minimal complete definition

unsafeCreate, unwrap, length, append, replicate, map, take, drop

Associated Types

type Elem a

Basic element type. For IsStaticText [a], this is a.

Methods

unsafeCreate :: a -> Static a i

Simply wrap a value in a Static as is, assuming any length.

When implementing new IsStaticText instances, make this simply apply the constructor of Static.

This should only be used to implement IsStaticText.

For example, an expression like

>>> unsafeCreate "somestring" :: Static String 50
"somestring"

will typecheck, although the stored length information will not match actual string size. This may result in wrong behaviour of all functions defined for IsStaticText.

unwrap :: Static a i -> a

Forget type-level length, obtaining the underlying value.

Instances

IsStaticText ShortByteString

IsStaticText instance for ShortByteString uses intermediate ByteStrings (pinned) for all modification operations.

Defined in Data.StaticText.Class

Associated Types

data Static ShortByteString i

type Elem ShortByteString

Methods

unsafeCreate :: forall (i :: Nat). ShortByteString -> Static ShortByteString i

unwrap :: forall (i :: Nat). Static ShortByteString i -> ShortByteString

length :: ShortByteString -> Int

append :: ShortByteString -> ShortByteString -> ShortByteString

replicate :: Int -> Elem ShortByteString -> ShortByteString

map :: (Elem ShortByteString -> Elem ShortByteString) -> ShortByteString -> ShortByteString

take :: Int -> ShortByteString -> ShortByteString

drop :: Int -> ShortByteString -> ShortByteString

IsStaticText ByteString

Defined in Data.StaticText.Class

Associated Types

data Static ByteString i

type Elem ByteString

Methods

unsafeCreate :: forall (i :: Nat). ByteString -> Static ByteString i

unwrap :: forall (i :: Nat). Static ByteString i -> ByteString

length :: ByteString -> Int

append :: ByteString -> ByteString -> ByteString

replicate :: Int -> Elem ByteString -> ByteString

map :: (Elem ByteString -> Elem ByteString) -> ByteString -> ByteString

take :: Int -> ByteString -> ByteString

drop :: Int -> ByteString -> ByteString

IsStaticText Text

Defined in Data.StaticText.Class

Associated Types

data Static Text i

type Elem Text

Methods

unsafeCreate :: forall (i :: Nat). Text -> Static Text i

unwrap :: forall (i :: Nat). Static Text i -> Text

length :: Text -> Int

append :: Text -> Text -> Text

replicate :: Int -> Elem Text -> Text

map :: (Elem Text -> Elem Text) -> Text -> Text

take :: Int -> Text -> Text

drop :: Int -> Text -> Text

IsStaticText [a]

Defined in Data.StaticText.Class

Associated Types

data Static [a] i

type Elem [a]

Methods

unsafeCreate :: forall (i :: Nat). [a] -> Static [a] i

unwrap :: forall (i :: Nat). Static [a] i -> [a]

length :: [a] -> Int

append :: [a] -> [a] -> [a]

replicate :: Int -> Elem [a] -> [a]

map :: (Elem [a] -> Elem [a]) -> [a] -> [a]

take :: Int -> [a] -> [a]

drop :: Int -> [a] -> [a]

IsStaticText (Vector a)

Defined in Data.StaticText.Class

Associated Types

data Static (Vector a) i

type Elem (Vector a)

Methods

unsafeCreate :: forall (i :: Nat). Vector a -> Static (Vector a) i

unwrap :: forall (i :: Nat). Static (Vector a) i -> Vector a

length :: Vector a -> Int

append :: Vector a -> Vector a -> Vector a

replicate :: Int -> Elem (Vector a) -> Vector a

map :: (Elem (Vector a) -> Elem (Vector a)) -> Vector a -> Vector a

take :: Int -> Vector a -> Vector a

drop :: Int -> Vector a -> Vector a