How do you indent with Haskell code?

How do you indent with Haskell code?

[Andy Stewart]

Hi all,

I use haskell-mode to write Haskell code.
Haskell use whitespace indent code.
And if i write code with deep indent level.
Have many possible position can indent at current line.
Example:

case foo of
^
1
    ^
    2

Write code below *case foo of* have two possible indent position.
I use haskell-mode for indent, i hit "TAB" key to switch all possible
indent position.
Like above example, i can hit "TAB" to indent code between (1) and (2).

I will wonderful have anyone use others advanced indent method for
Haskell.
More ingenious and don't waist time to hit "TAB" key.

Any help?

  -- Andy