On Wed, Oct 27, 2010 at 4:30 PM, Martijn Schrage
On 21-10-10 01:01, Victor Nazarov wrote:
I've been working on this for some month and I think now I'm ready to share the results.
Great stuff! I've been looking for something like this for a long time.
If you add "|| transport.status == 0" to line 90 of examples/rts-common.js, it also works on a local file system.
Thank you, I'll fix it.
I played around with it a bit to see how easy it was to call JavaScript from Haskell, and it turned out to be straightforward. With a little guessing, I constructed a JavaScript representation of a thunk, which evaluates its string argument as a JavaScript expression and returns the resulting string to Haskell. This thunk can be passed to the JavaScript-compiled Haskell function. To pass it around in Haskell and force its evaluation, I constructed a simple monad.
Very cool. I'll incorporate your changes, If you don't mind. However, I have some minor remarks. You shouldn't override hscall function, or you may break partial application implementation. And you shouldn't overide properties of evalFn, I wonder that this doesn't break your example... var evalFn = new $hs.Func(1); evalFn.evaluate(arg) = function(arg) { var argStr = $hs.fromHaskellString(arg); var res = eval(argStr); return $hs.toHaskellString(arg); // This function should be added to $hs object/namespace }
Now, on your web page, you can do something like:
<input type="text" onkeyup="execHaskell('validate')" id="inputField"/>
and in a Haskell module:
validate :: JS () validate = do { inputValue <- eval "document.getElementById('inputField').value" ; exec $ "document.getElementById('inputField').style.backgroundColor="++ color inputValue } where color str = if and (map isDigit str) then "'white'" else "'red'"
I think we should do something like this: data JsObject = ... -- Should be made abstract and eval :: String -> [JsObject] -> JS JsObject So we can pass around javascript-objects in haskell program and bind them back into javascript calls. And use some conversion functions in case when we need data: jsObjectToString :: JsObject -> JS String jsObjectToInt :: JsObject -> JS Int -- Victor Nazarov