patch applied (haskell-prime-status): add ""Make $
left associative, like application"
Dan Weston
westondan at imageworks.com
Wed Apr 23 20:11:47 EDT 2008
John Meacham wrote:
> On Wed, Apr 23, 2008 at 09:52:11AM -0700, Simon Marlow wrote:
>> The problem with this is that
>>
>> f !x y
>>
>> would associate differently in an expression than it does on the left hand
>> side of an equation, where ! is the prefix bang-pattern operator. To make
>> this consistent we'd have to make ! a prefix operator in expressions, or
>> give it the same precedence as function application; both mean a new
>> extension.
>
> Hmm.. that is another possible solution to the ~ ! - thing, have ~ and !
> be prefix operators in general. with ~ meaning 'negate' in expressions.
> then parsing is the same everywhere.
Do prefix operators bind more or less tightly than infix operators?
Either way, one of the two expressions (~2^3) or (~y$z) will parse
somewhat unintuitively.
I would expect these to mean ~(2^3) and (~y) $ z respectively.
Dan
More information about the Haskell-prime
mailing list