Basic Usage

By default, Hayoo! searches for function names, module names, signatures and function descriptions. With every letter typed, Hayoo! will show the results it thinks are best matching the query as well as some suggestions on how the words from the query could be completed. Clicking one of these suggestions will replace the according word in the query.

Hayoo! displays results as a list of functions, including full qualified module name and the function signature. Clicking the function name will lead directly to the corresponding documentation while clicking the module name will lead to the documentation of the module. Additionally, Hayoo! shows a little bit of the function description (if available) and provides a link leading directly to the source of the function (if available).

Advanced Queries

If words are seperated by whitespace, Hayoo! will search for results containing both words. Instead of using whitespace, the explicit AND operator can be used. Hayoo! also supports OR and NOT operators, although the NOT operator may only be used together with AND, e.g. map NOT fold or map AND NOT fold. Operator precedence can be influenced using round parentheses. Phrases can be searched using double quotes, e.g. "this is a phrase".

Hayoo! always performs fuzzy queries. This means, it tries to find something even if the query contains spelling errors. For example, Hayoo! will still find "fold" if "fodl" is searched. If Hayoo! detects "->" in the query string, it will only search for signatures. A signature query may consist of explicit type names as well as type variables. For example, searching for "a -> b" will find signatures like "Int -> Bool".

Scope

Currently, Hayoo! searches all packages available on Hackage. Additionally, any Haskell documentation generated by Haddock can be included in Hayoo!. Just send a message including an URI where the documentation can be found to hayoo@holumbus.org.

About Hayoo!

Hayoo! is a search engine specialized on Haskell API documentation. The goal of Hayoo! is to provide an interactive, easy-to-use search interface to the documenation of various Haskell packages and libraries. Although the Hayoo! data is regularly updated, we might miss a package or library. If you think there is some documentation for Haskell modules available on the Internet which should be added to Hayoo!, just drop us a note at hayoo@holumbus.org and tell us the location where we can find the documentation.

Background

Hayoo! is an example application of the Holumbus framework and was heavily inspired by Hoogle. The Holumbus library provides the search and indexing backend for Hayoo!. Holumbus and Hayoo! have been developed by Sebastian M. Schlatt and Timo B. Hübel at FH Wedel University of Applied Sciences. The Holumbus framework provides the basic building blocks for creating highly customizable search engines. To demonstrate the flexibility of the framework by a very special use case, the Hayoo! Haskell API search was implemented using Holumbus.

Currently, Hayoo! is still in beta stage. This means, it can become unavailable unexpectedly, as we do some maintenance or add new features. Therefore you should not yet rely on Hayoo! as primary search engine for Haskell documentation.

Technical Information

Hayoo! is entirely written in Haskell, including the underlying webserver. The web interface uses the Janus application server, written by Christian Uhlig. This server allows easy and seamless integration of Haskell code in web applications.

Feedback

We would like to know what you think about Hayoo!, therefore you can reach us at hayoo@holumbus.org and tell us about bugs, suggestions or anything else related to Hayoo!.