GHC error message on type mismatch
qdunkan at gmail.com
Fri Nov 8 08:01:13 UTC 2013
On Thu, Nov 7, 2013 at 4:22 AM, David Luposchainsky
<dluposchainsky at googlemail.com> wrote:
> On 2013-11-07 12:52, Daniel Trstenjak wrote:
>> My problem is with 'Expected' and 'Actual', that I'm often unsure if
>> the compiler is "expecting" something or if I'm the expecting one
>> and the same goes for "actual".
> Funny you mention it; I think I just got too used to the fact that every
> time I see this error I have to take a step back to remember what it
> means exactly. Renaming it to "given" or "provided" would really help.
For what it's worth, I used to have the same confusion. But after a
few years it went away. Now it seems obvious and I don't really
understand how I was confused before, or how I got unconfused.
That's the classic problem with trying to make anything intuitive.
When I write my own typecheck msgs, I always write "Function expected
X, but received Y." That's not too far off from expected / actual,
though at least it has an explicit subject.
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