Proposal: Add (&) to Data.Function

John Wiegley johnw at
Tue Nov 20 20:02:09 CET 2012

>>>>> Andreas Abel <andreas.abel at> writes:

> Well, the obvious meaning of &= is bitwise-and-with, like in
>   x &= 0xff7f;
> isn't it? ;-)

I realize this is tongue-in-cheek, but & is not universally the "bit-wise and"
operator.  In the POSIX shell saying "foo & bar" means to start processing foo
asynchronously and then run "bar".  But that also breaks the piping analogy
lens is using & for, so hmm...

I think |>= and |>~ would just be unfortunate, and lens is likely to be one of
the biggest users of this new operator (at least at this point in time).

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

More information about the Libraries mailing list