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wayland-wire

Introduction

This package provides a way to generate both server and client Haskell-bindings from a wayland protocol definition in XML.

Generate bindings

Given an XML-protocol definition named test.xml

$(generateFromXml Client "test.xml")

can be used to generate the Haskell-bindings for the client side. The module with the generated code needs the following extensions to be enabled:

• FlexibleContexts
• MultiParamTypeClasses
• Rank2Types
• TemplateHaskell
• TypeFamilies

Use the bindings

The bindings will create an empty data-type for every interface. The wl_display interface in the core wayland protocol would for instance get the following definition:

data WlDisplay

and it would be made an instance of Dispatchable and DispatchInterace. This makes it possible to send signals or add slots. On the server side the slots are the requests, and the signals are the events. On the client side it is the other way around, since signals are always defined as the outgoing messages, while slots handle the incoming messages. For example, to send a display error from the server to the client one could do:

wlDisplayError (signals display) objIdOfBadObject errorCode "An error occured"

The W Monad-transformer can be used to track objects and their slot handlers, or you could define your own by making it an instance of MonadObject. You also need a Monad that implements MonadSend for the generated bindings to be able to send messages.