[Haskell-cafe] Fixity declaration extension

Twan van Laarhoven twanvl at gmail.com
Tue Aug 14 17:17:20 CEST 2012


On 14/08/12 13:46, Ketil Malde wrote:
> AntC <anthony_clayden at clear.net.nz> writes:
>
>> I agree. I don't declare operators very often, and when I do I always struggle
>> to remember which way round the precedence numbers go.
>     [...]
>> (Anything else we can bikeshed about while we're at it?)
>
>    infixl * before +
>
> Perhaps "before" and "after" clearer than "higher" and "lower"?

I would pick "tighter than" and "looser than", but I suppose that "before" and 
"after" are also clear enough. Or maybe "inside" and "outside"?

I don't think that we really need a new keyword for precedence declarations. The 
current "infix" would suffice if the default was for operators to be non-fix and 
of indeterminate precedence. Multiple fixity declarations for the same operator 
should then be allowed. Or perhaps just require that separate declarations use 
the same "infix[lr]?" keyword.


Twan



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