Data.Text.Builder.Linear

Builder for strict Text and ByteString, based on linear types. It consistently outperforms Data.Text.Lazy.Builder from text as well as a strict builder from text-builder, and scales better.

Documentation

newtype 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.

Constructors

Builder

Fields

• unBuilder :: Buffer %1 -> Buffer

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

runBuilder :: forall m. Builder %m -> Text

Run Builder computation on an empty Buffer, returning strict Text.

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

This function has a polymorphic arrow and thus can be used both in usual and linear contexts.

runBuilderBS :: forall m. Builder %m -> ByteString

Same as runBuilder, but returning a UTF-8 encoded strict ByteString.

fromText :: Text -> Builder

Create Builder, containing a given Text.

>>> :set -XOverloadedStrings
>>> fromText "foo" <> fromText "bar"
"foobar"

fromChar :: Char -> Builder

Create Builder, containing a given Char.

>>> fromChar 'x' <> fromChar 'y'
"xy"

In contrast to singleton, it's a responsibility of the caller to sanitize surrogate code points with safe.

fromAddr :: Addr# -> Builder

Create Builder, containing a null-terminated UTF-8 string, specified by Addr#.

>>> :set -XMagicHash
>>> fromAddr "foo"# <> fromAddr "bar"#
"foobar"

The literal string must not contain zero bytes \0 and must be a valid UTF-8, these conditions are not checked.

fromDec :: (Integral a, FiniteBits a) => a -> Builder

Create Builder, containing decimal representation of a given integer.

>>> fromChar 'x' <> fromDec (123 :: Int)
"x123"

fromHex :: (Integral a, FiniteBits a) => a -> Builder

Create Builder, containing hexadecimal representation of a given integer.

>>> :set -XMagicHash
>>> fromAddr "0x"# <> fromHex (0x123def :: Int)
"0x123def"

fromDouble :: Double -> Builder

Create Builder, containing decimal representation of a given Double.

>>> :set -XMagicHash
>>> fromAddr "pi="# <> fromDouble pi
"pi=3.141592653589793"