.vimrc

" Turn on syntax highlighting.
syntax on
set showmatch

" Disable the default Vim startup message.
set shortmess+=I

" Show colored column at width 80
set colorcolumn=80

" Automatically wrap at width 80 for markdown files
au BufRead,BufNewFile *.md setlocal textwidth=80

" Show line numbers.
set number

" This enables relative line numbering mode. With both number and
" relativenumber enabled, the current line shows the true line number, while
" all other lines (above and below) are numbered relative to the current line.
" This is useful because you can tell, at a glance, what count is needed to
" jump up or down to a particular line, by {count}k to go up or {count}j to go
" down.
set relativenumber

" The backspace key has slightly unintuitive behavior by default. For example,
" by default, you can't backspace before the insertion point set with 'i'.
" This configuration makes backspace behave more reasonably, in that you can
" backspace over anything.
set backspace=indent,eol,start

" This setting makes search case-insensitive when all characters in the string
" being searched are lowercase. However, the search becomes case-sensitive if
" it contains any capital letters. This makes searching more convenient.
set ignorecase
set smartcase

" Enable searching as you type, rather than waiting till you press enter.
set incsearch

" Unbind some useless/annoying default key bindings.
nmap Q <Nop> " 'Q' in normal mode enters Ex mode. You almost never want this.

" Always show the status line at the bottom, even if you only have one window
"open.
set laststatus=2

" open new split panes to right and bottom, which feels more natural
set splitbelow
set splitright

" quicker window movement
nnoremap <C-j> <C-w>j
nnoremap <C-k> <C-w>k
nnoremap <C-h> <C-w>h
nnoremap <C-l> <C-w>l

" use 4 spaces instead of tabs during formatting
set expandtab
set tabstop=4
set shiftwidth=4
set softtabstop=4

" line break
set lbr 

" highlight search
set hls

" set autoindent
set autoindent

" highlight current line, but only in active window
augroup CursorLineOnlyInActiveWindow
    autocmd!
    autocmd VimEnter,WinEnter,BufWinEnter * setlocal cursorline
    autocmd WinLeave * setlocal nocursorline
augroup END

" Tab completion
au FileType python set omnifunc=python3complete#Complete
let g:SuperTabDefaultCompletionType = "context"
set completeopt=menuone,longest,preview

" Highlight matches when jumping to next
nnoremap <silent> n 	n:call HLNext(0.1)<cr>
nnoremap <silent> N 	N:call HLNext(0.1)<cr>

function! HLNext (blinktime)
	highlight WhiteOnRed ctermfg=white ctermbg=red
	let [bufnum, lnum, col, off] = getpos('.')
	let matchlen = strlen(matchstr(strpart(getline('.'),col-1),@/))
	let target_pat = '\c\%#'.@/
	let ring = matchadd('WhiteOnRed', target_pat, 101)
	redraw
	exec 'sleep ' . float2nr(a:blinktime * 1000) . 'm'
	call matchdelete(ring)
	redraw
endfunction

" Maximum text width
set textwidth=78

:" Map Ctrl-A -> Start of line, Ctrl-E -> End of line
:noremap <C-a> <Home>
:noremap <C-e> <End>
:inoremap <C-a> <Home>
:inoremap <C-e> <End>

" Strip double spaces from eol in markdown
function! <SID>StripTrailingWhitespaces()
	let l = line(".")
	let c = col(".")
	%s/\s\s\+$/\ /e
	call cursor(l, c)
endfun
autocmd BufWritePre *.md :call <SID>StripTrailingWhitespaces()

" Try to prevent bad habits like using the arrow keys for movement. This is
" not the only possible bad habit. For example, holding down the h/j/k/l keys
" for movement, rather than using more efficient movement commands, is also a
" bad habit. The former is enforceable through a .vimrc, while we don't know
" how to prevent the latter.
" Do this in normal mode...
nnoremap <Left>  :echoe "Use h"<CR>
nnoremap <Right> :echoe "Use l"<CR>
nnoremap <Up>    :echoe "Use k"<CR>
nnoremap <Down>  :echoe "Use j"<CR>
" ...and in insert mode
inoremap <Left>  <ESC>:echoe "Use h"<CR>

" ------------------------
" Plugin Configurations
" ------------------------

" NERDTree
nnoremap <C-n> :NERDTreeToggle<CR>
nnoremap <C-f> :NERDTreeFind<CR>
let NERDTreeIgnore=['\.pyc$', '\~$']

" colorscheme
colorscheme Monokai

" NERDComment
" Add spaces after comment delimiters by default
let g:NERDSpaceDelims = 1
" Use compact syntax for prettified multi-line comments
let g:NERDCompactSexyComs = 1
" Align line-wise comment delimiters flush left instead of following code
" indentation
let g:NERDDefaultAlign = 'left'
" Allow commenting and inverting empty lines (useful when commenting a region)
let g:NERDCommentEmptyLines = 1
" Enable trimming of trailing whitespace when uncommenting
let g:NERDTrimTrailingWhitespace = 1