[Haskell-beginners] Question on syntax

[Bob Ippolito]

Round braces are used for grouping, it's necessary to avoid ambiguity since
a function can be defined with more than one argument. When using case you
don't have this potential ambiguity, so don't need the parentheses. Tuples
are more of a special case in the grammar that isn't closely related to
this.

safeHead p = case p of
  [] -> Nothing
  x : xs -> Just x

On Friday, October 24, 2014, Rohit Sharma <rohits79 at gmail.com> wrote:

> All,
>
> I started learning haskell very recently and have a question on the
> pattern matching style for lists.
>
> In the below snippet i.e. "(x:xs)" why do we went with round braces and
> not square? I know we are using cons that tells this is not a tuple but
> would it not make more sense to write something like [x:xs] instead of
> (x:xs), i thought round braces was used for pair/tuples?
>
> safeHead [] = Nothing
> safeHead (x:xs) = Just x
>
> Thanks,
> Rohit
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/beginners/attachments/20141024/3a340d8a/attachment.html>