David Virebayre schrieb:

Isn't the proposal about :

\begin{code} main = do if True then putStrLn "1" ;else putStrLn "2" \end{code}

This should go through, too, but also does not for me according to http://hackage.haskell.org/trac/haskell-prime/wiki/DoAndIfThenElse <cite> Change the syntax for conditionals to exp -> if exp1 [;] then exp2 [;] else exp3 i.e., add optional semicolons before then and else, making the above example legal. This has been recently added to jhc, GHC and Hugs, and so far it has not caused any problems. </cite> But the main purpose of the proposal was to support the notation without ";" and the indentation by at least one character. I just do not see that it "has been recently added to GHC" I've checked ghc-6.10.4 and 6.12.0.20091010 Cheers Christian

On Thu, Nov 26, 2009 at 03:14:13PM +0100, Christian Maeder wrote:

David Virebayre schrieb:

...

On Thu, Nov 26, 2009 at 10:29 AM, Christian Maeder mailto:Christian.Maeder@dfki.de> wrote:

I wonder why I still get a "parse error (possibly incorrect indentation)" for:

\begin{code} main = do if True then putStrLn "1" else putStrLn "2" \end{code}

This works with hugs!

...

Isn't the proposal about :

\begin{code} main = do if True then putStrLn "1" ;else putStrLn "2" \end{code}

This does not work with hugs. ";" must be indented further.

\begin{code} main = do if True then putStrLn "1"; else putStrLn "2" \end{code}

This does also not work with hugs (";" at the end)

In both cases you have 2 semi-colons before the else (after the layout rule has been applied). Thanks Ian