double-conversion: Fast conversion between double precision floating point and text

[ bsd3, library, text ] [ Propose Tags ]

A library that performs fast, accurate conversion between double precision floating point and text.

This library is implemented as bindings to the C++ double-conversion library written by Florian Loitsch at Google:

The Text versions of these functions are about 30 times faster than the default show implementation for the Double type.

The ByteString versions are slower than the Text versions; roughly half the speed. (This seems to be due to the cost of allocating ByteString values via malloc.)

As a final note, be aware that the bytestring-show package is about 50% slower than simply using show.

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Dependencies base (==4.*), bytestring, ghc-prim, text (>= && <1.3) [details]
License BSD-3-Clause
Author Bryan O'Sullivan <>
Maintainer Bryan O'Sullivan <>
Revised Revision 1 made by Bodigrim at 2022-01-16T18:21:29Z
Category Text
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Source repo head: git clone
head: hg clone
Uploaded by BryanOSullivan at 2016-12-13T19:37:41Z
Distributions Arch:, Debian:, FreeBSD:, LTSHaskell:, NixOS:, Stackage:, openSUSE:
Downloads 39538 total (386 in the last 30 days)
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Status Hackage Matrix CI
Docs available [build log]
Last success reported on 2016-12-13 [all 1 reports]



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Welcome to double-conversion

double-conversion is a fast Haskell library for converting between double precision floating point numbers and text strings. It is implemented as a binding to the V8-derived C++ double-conversion library.

Join in!

We are happy to receive bug reports, fixes, documentation enhancements, and other improvements.

Please report bugs via the github issue tracker.

Master git repository:

  • git clone git://

There's also a Mercurial mirror:

  • hg clone

(You can create and contribute changes using either git or Mercurial.)


This library is written and maintained by Bryan O'Sullivan,