[Haskell-cafe] It's not a monad - what is it? looking for nice syntactic sugar, customizable do notation?

[Yitzchak Gale]

Marc Weber wrote:
> (3) Third idea:
>  xmlWithInnerIO <- execXmlT $ do
>    xmlns "http://www.w3.org/1999/xhtml" >> lang "en-US" >> xml:lang "en-US"
>    head $ title $ text "minimal"
>    body $ do
>      args <- lift $ getArgs
>      h1 $ text "minimal"
>      div $ text $ "args passed to this program: " ++ (show args)
> I still think that (3) would be superiour..
> Is there a way to define my own >>= and >> functions such as:

There is also the combinator approach of Text.Html, which
gives you a syntax similar to (3) but without abusing "do":

(rootElt ! [xmlns "http://www.w3.org/1999/xhtml",
           lang "en-US" >> xml:lang "en-US"]) $ concatXml
  [head $ title $ text "minimal"
  ,body $ concatXml
    [h1 $ text "minimal"
    ,div $ text $ "args passed to this program: " ++ (show args)
    ]
  ]

You use concatXml (it's concatHtml in the library) followed
by a list, instead of do, for nesting.

(Also, it's stringToHtml instead of text in the library.)

A few more brackets, but still pretty clean. Also, you'll have
pass in your args from somewhere else, in the IO monad -
which is probably a better design anyway.

Regards,
Yitz