patch applied (haskell-prime-status): BangPatterns: probably accept ==> undecided

Simon Marlow marlowsd at
Mon Apr 21 16:36:33 EDT 2008

Sittampalam, Ganesh wrote:
>> Incedentally I think we should use a different operator for array
>> indexing, because ! is almost universally used to mean "strict"
>> now: in bang patterns, strict datatype fields, and $!.  See
> A lot of the discussion on that page pre-supposes that CompositionAsDot
> will be accepted. Does it really stand a chance? It would be enormously
> disruptive and uglify the language massively. Making it necessary to
> use non-ASCII characters would be a big practical problem, I think.

Here are the possibilities for composition:

0. do nothing
1. use a Unicode operator for composition
2. require spaces around . as an operator
3. require spaces around all operators
4. use another ASCII operator for composition, e.g. <<<

Nothing has been decided yet, but most of the committee tends to favour 
(2), with some expressing a slight preference for (0).  We've pretty 
much ruled out (1) and (3) as too radical, and as you say using Unicode 
is still too impractical.

There is some uncertainty about the precise details of (2), and thinking 
about that is what lead to my proposal about changing the syntax of 
qualified operators.


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