Proposal: require spaces around the dot operator

Greg Weber greg at
Fri Feb 10 03:41:48 CET 2012

There are 2 compelling reasons I know of to prefer dot for record access
1) follows an almost universal convention in modern programming languages
2) is consistent with using the dot to select functions from module name-spaces

We can have a lot of fun bike-shedding about what operator we would
prefer were these constraints not present. Personally I wouldn't care.
However, I find either one of these 2 points reason enough to use the
dot for record field access, and even without a better record system
the second point is reason enough to not use dot for function

It is somewhat convenient to argue that it is too much work and
discussion for something one is discussing against. The only point
that should matter is how existing Haskell code is effected.

On Thu, Feb 9, 2012 at 8:27 PM, Daniel Peebles <pumpkingod at> wrote:
> I'm very happy to see all the work you're putting into the record
> discussion, but I'm struggling to see why people are fighting so hard to get
> the dot character in particular for field access. It seems like a huge
> amount of work and discussion for a tiny bit of syntactic convenience that
> we've only come to expect because of exposure to other very different
> languages.
> Is there some fundamental reason we couldn't settle for something like # (a
> valid operator, but we've already shown we're willing to throw that away in
> the MagicHash extension) or @ (only allowed in patterns for now)? Or we
> could even keep (#) as a valid operator and just have it mean category/lens
> composition.
> Thanks,
> Dan
> On Thu, Feb 9, 2012 at 9:11 PM, Greg Weber <greg at> wrote:
>> Similar to proposal #20, which wants to remove it, but immediately
>> less drastic, even though the long-term goal is the same.
>> This helps clear the way for the usage of the unspaced dot as a record
>> field selector as shown in proposal #129.
>> After this proposal shows clear signs of moving forward I will add a
>> proposal to support a unicode dot for function composition.
>> After that we can all have a lively discussion about how to fully
>> replace the ascii dot with an ascii alternative such as <~ or <<<
>> After that we can make the dot operator illegal by default.
>> This has already been discussed as part of a records solution on the
>> ghc-users mail list and documented here:
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