Haskell - highlighting of instance declaration following class declaration

[tmcopeland]

Description

I found some strange behavior in Sublime's Haskell highlighting. The relevant code is from the Learn You A Haskell book, specifically the paragraph called "A yes-no typeclass".

class YesNo a where
    yesno :: a -> Bool

instance YesNo Int where
    yesno 0 = False
    yesno _ = True

instance YesNo [a] where
    yesno [] = False
    yesno _ = True

-- more instances ...

In the second code block, immediately following the typeclass declaration, the words instance and where do not highlight. This is irrespective of the order of the instance declarations. If I swap the instance declarations, the same thing happens, and additionally the expression [] does not highlight.

Oddly, this highlights as expected:

class YesNo a where
    {yesno :: a -> Bool}
-- ...

as does

class YesNo a where { yesno :: a -> Bool }
-- ...

but not if I break the line after the left brace.

class YesNo a where {
    yesno :: a -> Bool }
-- ...

It highlights as expected in gedit. See the images below.

Environment

• Build 3176, Ubuntu 18.10, GNOME
• No packages installed that would affect Haskell highlighting

[jacksoncooper]

This is similar to #1320. I have a patch written and will open a pull request when I'm done with the test cases. I don't think the curly braces affect the highlighting because they're ignored by the syntax file. The issue occurs because the context responsible for highlighting type signatures is not always popped when it should be.

[wbond]

This issue has been solved by a previous commit, hence it is being closed.