Re: Language.Haskell.Parser and layout rules

18 Feb 2005


      On Thu, Feb 17, 2005 at 02:17:42PM +0000, Malcolm Wallace wrote:
...
Ross Paterson  writes:
...
The Report (section 9.3, especially notes 1 and 2) says "A nested context
must be further indented than the enclosing context", so this is illegal.
GHC and Hugs have innovated here, ...
I see you are using "innovated" here in the Microsoft sense, meaning
"undocumented and incompatible departure from standards".  :-)
I think of this as a very useful feature. it should be documented in the
extensions section. mainly, I find it very useful in two circumstances:

short circuit return:

main = do
        foo 
        if bar then return baz else do
        whizz 
        bang

with declarations

main = do
        withCString x $ \x' -> do
        withCString y $ \y' -> do
        c_func x' y'

    John

-- 
John Meacham - ⑆repetae.net⑆john⑈