Add haskell indentation to vim.

1 files changed, 85 insertions, 0 deletions

diff --git a/.vim/indent/haskell.vim b/.vim/indent/haskell.vim
new file mode 100644
index 0000000..dc7c649
--- /dev/null
+++ b/.vim/indent/haskell.vim
@@ -0,0 +1,85 @@
+" Vim indent file
+" Language:     Haskell
+" Author:       motemen <motemen@gmail.com>
+" Version:      0.1
+" Last Change:  2007-07-25
+"
+" Modify g:haskell_indent_if and g:haskell_indent_case to
+" change indentation for `if'(default 3) and `case'(default 5).
+" Example (in .vimrc):
+" > let g:haskell_indent_if = 2
+
+if exists('b:did_indent')
+    finish
+endif
+
+let b:did_indent = 1
+
+if !exists('g:haskell_indent_if')
+    " if bool
+    " >>>then ...
+    " >>>else ...
+    let g:haskell_indent_if = 3
+endif
+
+if !exists('g:haskell_indent_case')
+    " case xs of
+    " >>>>>[] -> ...
+    " >>>>>(y:ys) -> ...
+    let g:haskell_indent_case = 5
+endif
+
+setlocal indentexpr=GetHaskellIndent()
+setlocal indentkeys=!^F,o,O
+
+function! GetHaskellIndent()
+    let line = substitute(getline(getpos('.')[1] - 1), '\t', repeat(' ', &tabstop), 'g')
+
+    if line =~ '[!#$%&*+./<=>?@\\^|~-]$\|\<do$'
+        return match(line, '\s*where \zs\|\S') + &shiftwidth
+    endif
+
+    if line =~ '{$'
+        return match(line, '\s*where \zs\|\S') + &shiftwidth
+    endif
+
+    if line =~ '^\(instance\|class\).*\&.*where$'
+        return &shiftwidth
+    endif
+
+    if line =~ ')$'
+        let pos = getpos('.')
+        normal k$
+        let paren_end   = getpos('.')
+        normal %
+        let paren_begin = getpos('.')
+        call setpos('.', pos)
+        if paren_begin[1] != paren_end[1]
+            return paren_begin[2] - 1
+        endif
+    endif
+
+    if line !~ '\<else\>'
+        let s = match(line, '\<if\>.*\&.*\zs\<then\>')
+        if s > 0
+            return s
+        endif
+
+        let s = match(line, '\<if\>')
+        if s > 0
+            return s + g:haskell_indent_if
+        endif
+    endif
+
+    let s = match(line, '\<do\s\+\zs[^{]\|\<where\s\+\zs\w\|\<let\s\+\zs\S\|^\s*\zs|\s')
+    if s > 0
+        return s
+    endif
+
+    let s = match(line, '\<case\>')
+    if s > 0
+        return s + g:haskell_indent_case
+    endif
+
+    return match(line, '\S')
+endfunction