Add Bounded Char instance

[garyb]

This was previously an orphan in Data.Char, and also was wrong - the bottom and top values were reversed.

I'm not sure whether this is strictly speaking a breaking change or not, so not sure what we want to do about versioning here.

[garyb]

I implemented the values through the FFI to avoid having to move fromCharCode over also, by the way.

[paf31]

Sorry, Just woke up, didn't mean to merge this. Brain is on auto-pilot. I've reverted it for now. PR looks good though.

[garyb]

Hah, no problem. Merging is fine anyway, the question is just about whether we want to bump to v0.2.0 for this... might be a bit painful as I've still not got a working auto-version-bump tool.

[paf31]

I think we have to ... right? If someone already has Prelude and installs the latest strings, their code will be busted :(

[garyb]

Removing the Bounded Char instance from strings was a breaking change though, I versioned that one as such... it's more a case of it might break for people with the older strings if they get the newer prelude.

[garyb]

If the previous Bounded Char instance wasn't entirely broken (inverted top and bottom) I'd probably agree it is a breaking change, but I have to assume nobody was using it previously...

[garyb]

And one final point - the old strings does compile with the new Prelude, it's only a problem when the instance search is triggered.

[paf31]

Ah ok. Maybe we can get away with it then? I don't think any code uses this instance yet.

But then, we've been bitten by things like this before :(

[paf31]

Sorry, now I see. Yes, minor version bump for Prelude, major for strings makes sense.

[paf31]

I'll revert my revert then?

[garyb]

Haha, sure :)

[paf31]

Alright done, I'll tag.

[paf31]

So we need to bump everything which depends on strings, right? How many things is that?

[garyb]

It's not too bad, I've already started doing it:

purescript-enums
purescript-quickcheck
purescript-maps
purescript-datetime
purescript-sets
purescript-graphs

[garyb]

(enums needed the prelude update first)