Hi James, I think you meant to reply to the list. For one, I wouldn't consider GUI programming based on HTML as declarative, since more often than not, the format says nothing about its behavior, and when it does, it's through javascript, which is hardly declarative. Regards, Paul Liu On Tue, Jul 12, 2011 at 5:17 AM, James Deng wrote:

These days, more and more GUI programming are done in declarative, such as HTML(jQuery), Mozilla XUL, android UI XML.

Haskell is an excellent declarative language, so should have the advantages of constructing GUI in declarative, intuitive and powerful way. But so far, there is not such a GUI library intuitive like Html, powerful like XUL.

I expect something like html to layout GUI, and a haskell GUI engine would render the user interfaces files. Where is the gap lying?

On 07/12/2011 05:51 AM, Paul Liu wrote:

You guys might want to checkout the recent work on Euterpea at Yale CS. In particular:

1. Paul Hudak is writing a new book. http://plucky.cs.yale.edu/cs431/reading.htm 2. It uses FRP and arrows for sound synthesis. 3. It combines FRP signals with monadic (which recently gets re-written in arrows) GUI composition. 4. New novel techniques is being developed to handle I/O within arrows framework.

The code can be obtained through darcs, details at http://plucky.cs.yale.edu/cs431/software_resources.htm

Notably, the way it handles GUI is that the composition of widgets are static, but the signals flowing between them are dynamic. This closely follows Conal Elliott's Phooey approach, and greatly reduces the complexity of GUI programming.

Disclaimer: I was an ex-student who worked on this project.

Regards, Paul Liu

On Thu, Jul 7, 2011 at 11:08 PM, Heinrich Apfelmus wrote:

Dear Haskellers,

Can GUI programming be liberated from the IO monad?

Regards, -- James Deng http://cnjdeng.appspot.com

-- Regards, Paul Liu