> Sorry, I forgot to explain (probably because I'm too used to
it). I am referring to a syntax for easy creation of maps. Something equivalent to lists:
>
> to build a list: [ 1, 2, 3]
> to build a map; { 1, "one", 2, "two", 3, "three"}
>
> Without it I am always forced to use fromList.
This looks like something to use records for, or in any case something where association list performance is not an issue.
If you just want to store some configuration-like structure and pass it around, a record is great for this. You might find where in other languages you would simply leave a key "null", in Haskell you can just fill it with a Nothing.
Maps (hash or binary-tree) really pay off when they are filled dynamically with massive numbers of associations. I find when I am ending up in this scenario, I am generating my map programatically, not writing it as a literal.
Sometimes people even write maps simply as functions and not even as a data-structure.
> myMap char = case char of
> 'a' -> 1
> 'b' -> 2
> 'c' -> 3
Perhaps you could describe a situation you are in where you are wanting this, and we could see if there is something you can do already that is satisfying and solves your problem.