Font-lock misidentifying valid non-TH haskell as quasiquote

[sirlensalot]

To reproduce issue the following code anywhere in a .hs file: [True||False]

This will incorrectly grey out from '||' through the rest of the buffer.

I came across this because of another valid non-TH case: I defined an binary op |:, use it in a list, ie [1|:2, 3|:4], same problem.

There is no workaround other than adding extraneous space, a la #1185 . This is unsatisfactory as a resolution, to demand that people avoid valid Haskell syntax to please the quasiquoter font-lock.

A suggestion is that haskell-syntactic-face-function should ensure (parse-partial-sexp ... 'syntax-table) actually finds something and doesn't just blindly font-lock all the way to (point-max).

In the absence of that, and in light of the demise of #1185, can we at least have an option to disable quasi-quote fontlock altogether? Or customize the matching regex in syntax-table: my workaround for now is to add "DISABLEQUASIQUOTE" to that string to disable the font-lock.

Thanks, Stuart

[sirlensalot]

Yes please see desc, I reference it twice.

[geraldus]

Yeah, sorry, I tried to answer too fast :D

[geraldus]

As for me, I see the only one right way to solve this puzzle — to take into account file-local pragmas and cabal file pragmas (in case when cabal file is present). Obviously, this approach requires some caching of project configuration, hence observation of cabal file changes and file-local pragmas. But I always try to complicate things, described method is likely would bring some degree of complexity.

@gracjan I have no strong opinion on this right now.

[gracjan]

GHCi, version 7.10.2: http://www.haskell.org/ghc/  :? for help
Prelude> :set -XQuasiQuotes 
Prelude> let x = [True||False]
Prelude> let x = [true||False]

<interactive>:5:15: unterminated quasiquotation at end of input
Prelude> 

This means that QuasiQuotes can only be started by varid and we can rule out True because it starts with upper case and rule out 1 because it is a number.

[gracjan]

@slpopejoy: Can you add test cases for [1|:...] and [True||...] and mark them as failing? Put it in tests/haskell-font-lock-tests.el, thanks.