matzko / elm-opaque-dict Goto Github PK

> import Dict
> let a = Dict.singleton 0 0 in Dict.update 0 (\_ -> Nothing) a
Dict.fromList [] : Dict.Dict number number1
> let a = Dict.singleton 0 0 in Dict.update 0 (\_ -> Nothing) a
Dict.fromList [] : Dict.Dict number number1

When using update, mapping to Nothing means to remove the element, whereas in this package it leaves it untouched.

Fixing this would be a breaking change because it changes the behavior, but not a breaking API change.

I see three approaches:

1. document the difference
2. fix the implementation (from withDefault ... >> Tuple.pair ... >> Just to Maybe.map (Tuple.pair ...)), put a warning somewhere, hope users read it
3. add a dummy export, publish a minor version, then fix as above while removing the dummy export to force a major version (this still requires a warning but should avoid surprises, users are supposed to check what a major version bump entails

Using Dict.size prevents the need to allocate the intermediate lists