Deprecating fromIntegral

Carter Schonwald carter.schonwald at
Fri Sep 22 11:30:42 UTC 2017

I’m -10 in this proposal

Every time I write a number literal I’ll now get a warning.  Cause as it
hasn’t been remarked : every integer literal uses these operations afaik

The intent / spirit of this proposal is correct, the method of recourse

On Thu, Sep 21, 2017 at 7:20 PM Niklas Hambüchen <mail at> wrote:

> On 21/09/17 19:27, Evan Laforge wrote:
> > If I were to suddenly get 10,000 lines of warnings...
> If the built tool is set up sensibly (perhaps we should make it so if
> that is not already possible, but I think these days warnings of
> dependency packages are omitted anyway, as cabal and stack build them in
> parallel), you should get (and care about and fix) only warnings about
> those occurrences that are in the packages you maintain / build directly.
> You are unlikely to get 10,000 warnings:
> I've made a quick histogram over all of Hackage (note, this includes
> lots of abanoned code)
> There is also a JSON file containing counts for each packet so that you
> can quickly look up how many occurrences your packages have.
> Most packages have < 3 occurrences of fromIntegral, a few have < 20
> occurrences. Very few have more than 20.
> Assuming we go for a naming improvement and add 3 functions ala
> maybeFromInteger / runtimeCheckedFromInteger / fromIntegerWrap, a
> package owner would have to step through their deprecation warnings and
> replace each with one of the new 3 functions to get their package
> warning-free.
> I estimate this to be a very minor task/effort compared to the major
> changes GHC Haskell has gone through in the last years.
> I could probably already have fixed 1000 of the 7000 total occurrences
> on Hackage myself within the time it as taken me to debug integer
> conversion related problems in GHC/base in the last week.
> (In other words, these changes are cheap and have high payoff.)
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