indent setting is not functioning?

[HuStmpHrrr]

in my .vim/ftplugin/haskell.vim i have following settings:

let g:haskell_enable_quantification   = 1 " to enable highlighting of forall
let g:haskell_enable_recursivedo      = 1 " to enable highlighting of mdo and rec
let g:haskell_enable_arrowsyntax      = 1 " to enable highlighting of proc
let g:haskell_enable_pattern_synonyms = 1 " to enable highlighting of pattern
let g:haskell_enable_typeroles        = 1 " to enable highlighting of type roles
let g:haskell_enable_static_pointers  = 1 " to enable highlighting of static
let g:haskell_indent_if               = 3
let g:haskell_indent_case             = 2
let g:haskell_indent_let              = 4
let g:haskell_indent_where            = 6
let g:haskell_indent_do               = 3
let g:haskell_indent_in               = 1

however, it's not working. for example,

   if bool
|<- curcor is here
      | instead of here

I use pathogen to manage my plugins, and here are the plugins i currently have:

$ ls bundle/
ghcmod-vim  haskell-vim  neco-ghc  nerdtree  python-mode  syntastic  tabular  taglist  vimerl  vim-fugitive  vim-markdown  vimproc.vim

is there any possible conflict between them?

however, there seems to be no extra ftplugin for haskell:

$ find bundle/ -name 'haskell.vim' -type f
bundle/haskell-vim/ftplugin/haskell.vim
bundle/haskell-vim/syntax/haskell.vim
bundle/haskell-vim/ftdetect/haskell.vim
bundle/haskell-vim/indent/haskell.vim
bundle/haskell-vim/after/ftplugin/haskell.vim

and i am sure haskell-vim is loaded since i can use :HaskellAddModuleComment.

could you please have a look? it would be nice to let me know where the problem is.

[VictorVolovik]

As stated in README you need additionally install vim-hindent for such settings.