The transformers-compat package

[Tags: bsd3, library]

This package includes backported versions of types that were added to transformers in transformers 0.3 and 0.4 for users who need strict transformers 0.2 or 0.3 compatibility to run on old versions of the platform, but also need those types.

Those users should be able to just depend on transformers >= 0.2 and transformers-compat >= 0.3.

Note: missing methods are not supplied, but this at least permits the types to be used.

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Versions0.1, 0.1.1,, 0.2, 0.3, 0.3.2, 0.3.3,,,,,,
Change logCHANGELOG.markdown
Dependenciesbase (>=4.3 && <5), transformers (>=0.4.1 && <0.5) [details]
CopyrightCopyright (C) 2012 Edward A. Kmett
AuthorEdward A. Kmett
MaintainerEdward A. Kmett <>
Home page
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Source repositoryhead: git clone git://
UploadedFri Feb 13 07:29:40 UTC 2015 by EdwardKmett
DistributionsDebian:, Fedora:, FreeBSD:, LTSHaskell:, NixOS:, Stackage:
Downloads142355 total (120 in last 30 days)
1 []
StatusDocs available [build log]
Last success reported on 2015-02-13 [all 1 reports]




twoUse transformers 0.2. This must be selected manually and should probably only be used on older GHCs around 7.0.x.DisabledManual
threeUse transformers 0.3. This should toggle on/off automatically.DisabledManual
mtl-f-mtl Disables support for mtl for transformers 0.2 and 0.3. That is an unsupported configuration, and results in missing instances for `ExceptT`, but keeps the package Haskell 98.EnabledManual

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info


Maintainers' corner

For package maintainers and hackage trustees

Readme for transformers-compat-


Build Status

This provides a thin compatibility shim on top of transformers-0.2 to add the types that were added in transformers-0.3.

This enables users to maintain haskell-platform compatibility, while still gaining access ot the new functionality.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on

-Edward Kmett