blaze-builder

Efficient buffered output.

https://github.com/blaze-builder/blaze-builder

LTS Haskell 24.33:0.4.4.1
Stackage Nightly 2026-03-13:0.4.4.1
Latest on Hackage:0.4.4.1

See all snapshots blaze-builder appears in

BSD-3-Clause licensed by Jasper Van der Jeugt, Simon Meier, Leon P Smith
Maintained by https://github.com/blaze-builder
This version can be pinned in stack with:blaze-builder-0.4.4.1@sha256:f7bc95f78aaf183389c227f8754efca8a951b66bc0752e11b0af6c8b723279f4,3411

Module documentation for 0.4.4.1

  • Blaze
    • Blaze.ByteString
      • Blaze.ByteString.Builder
        • Blaze.ByteString.Builder.ByteString
        • Blaze.ByteString.Builder.Char
          • Blaze.ByteString.Builder.Char.Utf8
        • Blaze.ByteString.Builder.Char8
        • Blaze.ByteString.Builder.Compat
          • Blaze.ByteString.Builder.Compat.Write
        • Blaze.ByteString.Builder.HTTP
        • Blaze.ByteString.Builder.Html
          • Blaze.ByteString.Builder.Html.Utf8
          • Blaze.ByteString.Builder.Html.Word
        • Blaze.ByteString.Builder.Int
        • Blaze.ByteString.Builder.Internal
          • Blaze.ByteString.Builder.Internal.Write
        • Blaze.ByteString.Builder.Word
Depends on 3 packages(full list with versions):

Hackage version blaze-builder on Stackage Nightly Stackage LTS version Cabal build

blaze-builder

This library allows to efficiently serialize Haskell values to lazy bytestrings with a large average chunk size. The large average chunk size allows to make good use of cache prefetching in later processing steps (e.g. compression) and reduces the system call overhead when writing the resulting lazy bytestring to a file or sending it over the network.

This library was inspired by the module Data.Binary.Builder provided by the binary package. It was originally developed with the specific needs of the blaze-html package in mind. Since then it has been restructured to serve as a drop-in replacement for Data.Binary.Builder, which it improves upon both in speed as well as expressivity.

To see the improvements in speed, run the throughput benchmark, which measures serialization speeds for writing Word8, Word16, Word32 and Word64 in different endian formats and different chunk sizes, using the command

  make bench-throughput

or run the list serialization comparison benchmark

  make bench-blaze-vs-binary

Checkout the combinators in the module Blaze.ByteString.Builder.Write to see the improvements in expressivity. This module allows to incorporate efficient primitive buffer manipulations as parts of a builder. We use this facility in the blaze-html HTML templating library to allow for the efficient serialization of HTML escaped and UTF-8 encoded characters.

Changes

  • 0.4.4.1 2025-08-28

    • Drop unused dependency deepseq
    • Tested with GHC 8.0 - 9.14 alpha1

  • 0.4.4 2025-07-31

  • 0.4.3 2025-05-15

  • 0.4.2.3 2023-08-27

    • Fix compilation warnings concerning non-canonical mappend
    • Support bytestring-0.12
    • Support text-2.1
    • Tested with GHC 7.0.4 to 9.8.1 alpha3

  • 0.4.2.2

    • Support GHC 9.2

  • 0.4.2.1

    • Bump cabal file to Cabal >= 1.10

  • 0.4.2.0

    • Make semigroup instances unconditional
    • Support bytestring-0.11
    • Support semigroups-0.19

  • 0.4.1.0

    • Gain compatibility with the Semigroup/Monoid proposal
    • Add Word8 HTML escaping builders
    • Speed up fromHtmlEscapedText and fromHtmlEscapedLazyText

  • 0.4.0.2

    • Fixed warnings on GHC 7.10, courtesy of Mikhail Glushenkov.

  • 0.4.0.1

    • Tightened the version constraints on the bytestring package for GHC 7.8

  • 0.4.0.0

  • 0.3.3.0

    • exposed the ‘Buffer’ constructor to enable keeping around a pool of buffers.

  • 0.3.2.0

    • added ‘writeToByteString’ to construct a strict bytestring in a single step. We can actually view ‘Write’s as strict-bytestring builders.

  • 0.3.1.1

    • Changed imports of Foreign.Unsafe to make it GHC 7.8 compatible
    • -Wall clean on GHC 7.0 - 7.6

  • 0.3.1.0

    • Widened dependencies on text and bytestring

  • 0.3.0.1

    • Fix build warning in Blaze.ByteString.Builder.Word (contributed by Greg Weber)

  • 0.3.0.1

    • Remove comparison to the ‘text’ library encoding functions of ‘Blaze.Builder.Char.Utf8.fromText’ and ‘Blaze.Builder.Char.Utf8.fromLazyText’. Bryan O’Sullivan reported that on his 64-bit system with GHC 7.0.3 the ‘text’ library is 5x faster than the ‘blaze-builder’ library.

  • 0.3.0.0

    • Renamings in internal modules: WriteIO -> Poke and associated functions.

  • 0.2.1.4

    • Fixed bug: appending to ‘chunkedTransferEncoding somebuilder’ also encoded the appended builder, which is obviously wrong.

  • 0.2.1.3

    • Fixed bug: ‘chunkedTransferTerminator’ is now correctly set to “0\r\n\r\n”.

  • 0.2.1.2

  • 0.2.1.1

    • Reexport ‘Write’ datatype and ‘fromWriteList’, ‘fromWriteSingleton’, ‘fromWrite’ functions together with writes and builders for storables.
    • Add ‘MonoPatBinds’ language extension to (hopefully) solve the issues caused by GHC bug http://hackage.haskell.org/trac/ghc/ticket/4498

  • 0.2.1.0

    Incorporated several design changes:

    • Writable buffer range is now represented in a packed form. This improves speed slightly, as less currying is used.
    • Writes are abstracted such that their internal representation can be exchanged without breaking other library code.
    • Writes are represented in a form that allows for efficient monoid instances for branching code like UTF-8 encoding. For single character encoding this results currently in a slight slowdown due to GHC not recognizing the strictness of the returned value. This will be fixed in the future.
    • BuildSteps support returning a result in Done, which enables to implement a Put monad using CPS.
    • chunked list writes were removed, as they result in worse performance when writing non-trivial lists. (cf. benchmarks)
    • An internal buffering abstraction is introduced, which is used both by the adaption of the binary package, as well as by the blaze-builder-enumeratee package, to execute puts and builders. It will be used later also by the execution functions of the blaze-builder package.

    Implemented new functionality

    • Blaze.ByteString.Builder.HTTP provides a builder transformer for doing in-buffer chunked HTTP encoding of an arbitary other builder.
    • Blaze.ByteString.Builder.Char8 provides functions to serialize the lower 8-bits of characters similiar to what Data.ByteString.Char8 provides for bytestrings.

  • 0.2.0.3

    Loosen ‘text’ dependency to ‘>= 0.10 && < 0.12’

  • 0.2.0.2

    Fixed bug: use ' instead of ' for HTML escaping ’

  • 0.2.0.1

    Added a missing benchmark file.

  • blaze-builder-0.2.0.0

    Heavily restructured ‘blaze-builder’ such that ‘Blaze.ByteString.Builder’ serves as a drop-in replacement of ‘binary:Data.Binary.Builder’ which it improves upon with respect to both speed as well as expressivity. See the documentation and the benchmarks for details on improvements and new functionality.

    Changed module structure: Blaze.ByteString.Builder.Core -> Blaze.ByteString.Builder Blaze.ByteString.Builder.Utf8 -> Blaze.ByteString.Builder.Char.Utf8 Blaze.ByteString.Builder.Html -> Blaze.ByteString.Builder.Html.Utf8

    Changed function names: writeByte -> writeWord8 fromByte -> fromWord8 fromWriteList -> fromWrite1List

    Possibly performance sensitive implementation changes:

    • ‘fromByteString’ and ‘fromLazyByteString’ check now if a direct insertion of the bytestring(s) would be cheaper than copying it. See their documentation on how to recover the old behaviour.

    Deprecated functions: ‘empty’ : use ‘mempty’ instead ‘singleton’: use ‘fromWord8’ instead ‘append’ : use ‘mappend’ instead

  • blaze-builder-0.1

    This is the first version of ‘blaze-builder’. It is explicitely targeted at fast generation of UTF-8 encoded HTML documents in the ‘blaze-html’ and the ‘hamlet’ HTML templating libraries.