Proposal: Add (&) to Data.Function

John Wiegley johnw at
Tue Nov 20 20:11:48 CET 2012

>>>>> Edward Kmett <ekmett at> writes:

> At this time I haven't switched the %~ operators from %. I will miss the
> consistency that operator= or operator~ applies the operator to the target
> of the lens, like how += applies (+) to the target of an l-value, in this
> case, but i think it'd be silly to try too hard to be consistent across
> every use of % in lens and that %= for mod-equals still reads better than
> &=, which _is_ used in lens for bitwise .&. in data.bits.lens mosty because
> .&.= is silly looking ;)

And let's not forget that the current <%= operator would turn into <|>=, which
is completely unfortunate because it has nothing to do with <|>.

John Wiegley
FP Complete                         Haskell tools, training and consulting               johnw on #haskell/

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