Enable access to the operator Range

[lue-bird]

elm-syntax only gives us the operator symbol String but having access to the operator Range as well is valuable:

• we can replace only the operator instead of replacing everything between the operands, preserving comments and whitespace. → fixes https://github.com/jfmengels/elm-review-simplify/issues/46
• we can have a better error Range for operation simplification. Error ranges can quickly go out of hand which is the reason all function simplifications put the error range on the fnRange, not one of the arguments. Now we can do the same with operations

It seems this will be part of elm-syntax v8 https://github.com/stil4m/elm-syntax/issues/74 but now we can patch things up in the meantime :white_flower:

If the PR's solution seems too unstable and you want to wait for v8, I'm happy to wait as well.

Now what's included in this PR?

• finding the operator's range (skips searching in all comments) and saving it in the OperatorCheckInfo
• a more conservative fix for :: [ ... ] as hinted at in https://github.com/jfmengels/elm-review-simplify/issues/46
• tests

That means that if this PR would be merged, we still need to change the other error ranges to the operator ranges.

[jfmengels]

I strongly wish this will be part of elm-syntax v8 but now we can patch things up in the meantime (should I add an issue in elm-syntax?)

Yes, same here. It will happen one day :wink:

---

I'm a bit surprised about this PR, because I just merged the same thing in https://github.com/jfmengels/elm-review-simplify/pull/116/files#diff-6239bccafe2b75c7e560542732acf25d142d08608e1e0f0ffe9b53c09cfb1e0eR6540-R6545

I think we're doing the same thing, except that you're also handling comments, which is a good idea. Can you confirm that we're doing the same thing, or am I misunderstanding something? If we are, then can you try replacing my code by your version? Let's go with your version since it's going to be more correct.

[lue-bird]

Yeah, same thing, just more complicated. Very cool that we accidentally did it at almost the same time. Btw String.split "\n" --> String.lines would be a nice one to add ;)

[lue-bird]

try replacing my code by your version

Ok, I think we're good to go. Merge this anytime

[lue-bird]

merge whenever you feel like it (just avoid a merge commit please :pray:).

before I mess something up, I assume you want "rebase and merge"?

[jfmengels]

Yes (You do have some failing tests now though). But when you prefer, feel free to use "Squash and merge", your choice.

[lue-bird]

You do have some failing tests now though

Not sure I follow, the github action and the local setup say the tests pass

[jfmengels]

Huh weird, it showed as failing to me yesterday. Alright go ahead then 😊

[lue-bird]

Fixed a bug with pipeline into (parenthesized pipeline into composition). Removing the parens there is incorrect, for example

[[3,4]] |> (negate |> List.map >> List.map)
--> [[-3,-4]]

but

[[3,4]] |> negate |> List.map >> List.map
--> TYPE MISMATCH

This might have been handled by your old rule but now we at least have a test for it