Evaluate and display trees of predicates

Version on this page:
LTS Haskell 9.21:
Stackage Nightly 2017-07-25:
Latest on Hackage:

See all snapshots prednote appears in

BSD-3-Clause licensed by Omari Norman


prednote helps you build a tree of predicates that you can apply to a list of items. It was written for Penny:

but I also find it useful for dapi:

and so you might find it useful too.

prednote is on Github:

and Hackage:

Test results

You can view the results of building and testing on Travis by clicking the button below:

Build Status

If you have trouble building prednote due to dependency issues, try looking at the previous test results, as they will show you package versions that were used to build prednote successfully.

Something similar

See also rematch:

which is apparently based on a Java library called hamcrest.


prednote is licensed under the BSD license; see the LICENSE file.


* Documentation fixes.
* Completely new API and internals; is simpler and allows
for predicates on sum types.

* Dependency bumps.

* added wrap function.

* complete change in API and internals.

* updates for new Rainbow API

* test with GHC 7.8.2
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