Improved BuckleScript method call syntax

[SanderSpies]

#849

Changes Foo##bar into Foo."bar"

Note that ## still needs to used for scenario's like: Foo##(something."else").

Also #= has gotten an extra post space during printing as it otherwise will fail to be idempotent.

[chenglou]

Context: we're sticking with #= for the moment.

cc spam @bsansouci @Schmavery @jordwalke @yunxing, adding a space after #= ok? I recall some precedence problems around it?

Note that ## still needs to used for scenario's like: Foo##(something."else").

I don't think @bobzhang made such thing work. This compiles to something weird: https://bloomberg.github.io/bucklescript/js-demo/?gist=0d4169c80f571302b5a163ee01556a7e

[SanderSpies]

@jordwalke mentioned a better form: Foo["bar"]["more"]. I'll update this PR unless there are objections.

[chenglou]

That'd be a bit more tedious than ## and might mislead people into doing foo[stringRef] (though we can warn against that)

[SanderSpies]

It requires also some more work, so let's keep it as is.

[bobzhang]

@chenglou your example probably is a bug on BuckleScript, it should fail with a nice error msg

[bobzhang]

How about using '.=' instead of '#='

[SanderSpies]

@bobzhang could easily be added (did a quick experiment).

[SanderSpies]

Something goes wrong here.

[chenglou]

@bsansouci

[chenglou]

@bsansouci @jordwalke

[bsansouci]

What's wrong exactly?

[SanderSpies]

Nevermind, I was looking wrong.

[Schmavery]

Adding a space (before and) after #= shouldn't result in any parsing issues. In fact, it should fix #856

[SanderSpies]

Added support for .=.

[chenglou]

Is this ready?

[SanderSpies]

Yes, ready for review

[chenglou]

Fack. cc @yunxing is this good to go? If it is, @bobzhang everything's ready on BS' side right?

[bobzhang]

this is good, would you do a sanity check on your side that no # character in method name

[SanderSpies]

Updated with extra check for hash within method name.

[yunxing]

The parser && printer part looks good to me.

@chenglou Feel free to merge this if the syntax also looks good to you.

[chenglou]

This PR works but completely wrecks editor highlighting.

I can fix this for atom (and I guess vscode by extension), @jordwalke what about vim? cc @yunxing for emacs

[chenglou]

Will work on making the highlighting work then merge this tomorrow.