number is not comparable

[zwilias]

Fails

five : number
five =
    5

isSmallerThanFive : number -> Bool
isSmallerThanFive number =
    number < five

results in

-- TYPE MISMATCH ------------------------------------------ src/Basics/Extra.elm

The left argument of (<) is causing a type mismatch.

49|     number < five
        ^^^^^^
(<) is expecting the left argument to be a:

    comparable

But the left argument is:

    number

Hint: Only ints, floats, chars, strings, lists, and tuples are comparable.

Alternatives that do work:

Flipping the args

five : number
five =
    5

isSmallerThanFive : number -> Bool
isSmallerThanFive number =
    five > number

Doing something with the arg first

five : number
five =
    5


isSmallerThanFive : number -> Bool
isSmallerThanFive number =
    (number + 0) < five

Inlining the other number (?)

isSmallerThanFive : number -> Bool
isSmallerThanFive number =
    let
        five : number
        five =
            5
    in
        number < five

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[jvoigtlaender]

Isn't this a duplicate of #1281, which is already recorded in #1373?

[zwilias]

You're correct. Sorry for the dupe!

[evancz]

No need to be sorry @zwilias! As I outline in this thread, I think "duplicate" issues are valuable and very underrated in open source.

Your SSCCE looks clearer to me than the ones referenced by @jvoigtlaender, and I added it to the meta issue! Thank you!

@jvoigtlaender, in the future, can you just note for me that it belongs in the meta issue? In many of your posts like this, I get the sense that it feels a bit confrontational for the OP. No need for that, especially because I prefer "duplicates" with more examples over comments on existing issues!

[jvoigtlaender]

No passive aggression from my side.

[zwilias]

No passive agression or confrontation experienced on this side, I understand @jvoigtlaender is just triaging and happens to have an almost academical knowledge of open issues. Since dupes are preferred over comments, it makes sense to at least ensure they're cross-referenced.