Add purescript support, closes #110

indent/purescript.vim

@@ -0,0 +1,141 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'purescript') == -1
+  
+" indentation for purescript
+"
+" Based on idris indentation
+"
+" author: raichoo (raichoo@googlemail.com)
+"
+" Modify g:purescript_indent_if and g:purescript_indent_case to
+" change indentation for `if'(default 3) and `case'(default 5).
+" Example (in .vimrc):
+" > let g:purescript_indent_if = 2
+
+if exists('b:did_indent')
+  finish
+endif
+
+let b:did_indent = 1
+
+if !exists('g:purescript_indent_if')
+  " if bool
+  " >>>then ...
+  " >>>else ...
+  let g:purescript_indent_if = 3
+endif
+
+if !exists('g:purescript_indent_case')
+  " case xs of
+  " >>>>>[]     -> ...
+  " >>>>>(y:ys) -> ...
+  let g:purescript_indent_case = 5
+endif
+
+if !exists('g:purescript_indent_let')
+  " let x = 0 in
+  " >>>>x
+  let g:purescript_indent_let = 4
+endif
+
+if !exists('g:purescript_indent_where')
+  " where f :: Int -> Int
+  " >>>>>>f x = x
+  let g:purescript_indent_where = 6
+endif
+
+if !exists('g:purescript_indent_do')
+  " do x <- a
+  " >>>y <- b
+  let g:purescript_indent_do = 3
+endif
+
+setlocal indentexpr=GetPurescriptIndent()
+setlocal indentkeys=!^F,o,O,},=where,=in
+
+function! GetPurescriptIndent()
+  let prevline = getline(v:lnum - 1)
+  let line = getline(v:lnum)
+
+  if line =~ '^\s*\<where\>'
+    let s = match(prevline, '\S')
+    return s + 2
+  endif
+
+  if line =~ '^\s*\<in\>'
+    let n = v:lnum
+    let s = 0
+
+    while s <= 0 && n > 0
+      let n = n - 1
+      let s = match(getline(n),'\<let\>')
+    endwhile
+
+    return s + 1
+  endif
+
+  if prevline =~ '[!#$%&*+./<>?@\\^|~-]\s*$'
+    let s = match(prevline, '=')
+    if s > 0
+      return s + 2
+    endif
+
+    let s = match(prevline, ':')
+    if s > 0
+      return s + 3
+    else
+      return match(prevline, '\S')
+    endif
+  endif
+
+  if prevline =~ '[{([][^})\]]\+$'
+    return match(prevline, '[{([]')
+  endif
+
+  if prevline =~ '\<let\>\s\+.\+\(\<in\>\)\?\s*$'
+    return match(prevline, '\<let\>') + g:purescript_indent_let
+  endif
+
+  if prevline !~ '\<else\>'
+    let s = match(prevline, '\<if\>.*\&.*\zs\<then\>')
+    if s > 0
+      return s
+    endif
+
+    let s = match(prevline, '\<if\>')
+    if s > 0
+      return s + g:purescript_indent_if
+    endif
+  endif
+
+  if prevline =~ '\(\<where\>\|\<do\>\|=\|[{([]\)\s*$'
+    return match(prevline, '\S') + &shiftwidth
+  endif
+
+  if prevline =~ '\<where\>\s\+\S\+.*$'
+    return match(prevline, '\<where\>') + g:purescript_indent_where
+  endif
+
+  if prevline =~ '\<do\>\s\+\S\+.*$'
+    return match(prevline, '\<do\>') + g:purescript_indent_do
+  endif
+
+  if prevline =~ '^\s*\<data\>\s\+[^=]\+\s\+=\s\+\S\+.*$'
+    return match(prevline, '=')
+  endif
+
+  if prevline =~ '\<case\>\s\+.\+\<of\>\s*$'
+    return match(prevline, '\<case\>') + g:purescript_indent_case
+  endif
+
+  if prevline =~ '^\s*\<\data\>\s\+\S\+\s*$'
+    return match(prevline, '\<data\>') + &shiftwidth
+  endif
+
+  if (line =~ '^\s*}\s*' && prevline !~ '^\s*;')
+    return match(prevline, '\S') - &shiftwidth
+  endif
+
+  return match(prevline, '\S')
+endfunction
+
+endif