Handle Template Haskell / DataKinds names in haskell-indentation

[RafaelBocquet]

haskell-indentation currently can't handle names starting with quotes used by the TemplateHaskell and DataKinds ghc extensions.

e.g. (both 'A are needed to get this) :

a = a (a 'A))
       a 'A
    ^  ^ indentation point is here
    | but should be here 

A quick fix is to change

    (if (or (looking-at "'\\([^\\']\\|\\\\.\\)*'")
            (looking-at "\"\\([^\\\"]\\|\\\\.\\)*\"")
            (looking-at         ; Hierarchical names always start with uppercase
             "[[:upper:]]\\(\\s_\\|\\sw\\|'\\)*\\(\\.\\(\\s_\\|\\sw\\|'\\)+\\)*")
            (looking-at "\\(\\s_\\|\\sw\\)\\(\\s_\\|\\sw\\|'\\)*") ; Only unqualified vars can start with lowercase
            (looking-at "[0-9][0-9oOxXeE+-]*")
            (looking-at "[-:!#$%&*+./<=>?@\\\\^|~]+")
            (looking-at "[](){}[,;]")
            (looking-at "`[[:alnum:]']*`"))

to

    (if (or (looking-at "\"\\([^\\\"]\\|\\\\.\\)*\"")
            (looking-at         ; Hierarchical names always start with uppercase
             "[[:upper:]]\\(\\s_\\|\\sw\\|'\\)*\\(\\.\\(\\s_\\|\\sw\\|'\\)+\\)*")
            (looking-at "\\(\\s_\\|\\sw\\)\\(\\s_\\|\\sw\\|'\\)*") ; Only unqualified vars can start with lowercase
            (looking-at "[0-9][0-9oOxXeE+-]*")
            (looking-at "[-:!#$%&*+./<=>?@\\\\^|~]+")
            (looking-at "[](){}[,;]")
            (looking-at "`[[:alnum:]']*`")
            (looking-at "'\\([^\\']\\|\\\\.\\)*'"))

in haskell-indentation.el, i.e. to give char literals a lower precedence. It doen't seem to break anything, but I haven't really used it yet.

[gracjan]

A good start is to a a :expected-result :failed test case in tests/haskell-indentation-tests.el. Then run:

make check EMACS=/path/to/emacs

then add your fix and see if it fixed the issue and did not break anything more.