Invalid decoder for `Map` (dictionary) field about elm-export

[ehamberg]

Yep. Will do that next week.

[tekul]

@ehamberg Any chance you could submit your fix for the string key case as a PR? it seems to be the correct behaviour.

I was looking into this a bit more and aeson seems to stick with a simple key/value encoding for maps with simple types such as String or Int, so these will all fail with the current implementation as far as I an see, e.g.

> let x=M.fromList [(1, "1"), (2, "2"), (3, "3)] :: M.Map Int String
> Data.Aeson.encode x
"{\"1\":\"1\",\"2\":\"2\",\"3\":\"3\"}"

But for more complex cases, such as tuple keys, it switches to using lists:

>  x = M.fromList [((1,1),"1"),((2,2),"2"),((3,3),"3")]
> > Data.Aeson.encode x
"[[[1,1],\"1\"],[[2,2],\"2\"],[[3,3],\"3\"]]"

I'd expect the primitive (particularly string) key cases will be the most common, so it would be nice to have a fix in place.