Add support for vim-lsp

autoload/airline/extensions/lsp.vim

@@ -0,0 +1,67 @@
+" MIT License. Copyright (c) 2013-2019 François-Xavier Carton et al.
+" Plugin: https://github.com/prabirshrestha/vim-lsp
+" vim: et ts=2 sts=2 sw=2
+
+scriptencoding utf-8
+
+if !get(g:, 'lsp_loaded', 0)
+  finish
+endif
+
+function! s:airline_lsp_count(cnt, symbol) abort
+  return a:cnt ? a:symbol. a:cnt : ''
+endfunction
+
+function! s:airline_lsp_get_line_number(cnt, type) abort
+  let result = ''
+
+  if a:type ==# 'error'
+    let result = lsp#get_buffer_first_error_line()
+  endif
+
+  if empty(result)
+      return ''
+  endif
+
+  let open_lnum_symbol  =
+    \ get(g:, 'airline#extensions#lsp#open_lnum_symbol', '(L')
+  let close_lnum_symbol =
+    \ get(g:, 'airline#extensions#lsp#close_lnum_symbol', ')')
+
+  return open_lnum_symbol . result . close_lnum_symbol
+endfunction
+
+function! airline#extensions#lsp#get(type) abort
+  if !exists(':LspDeclaration')
+    return ''
+  endif
+
+  let error_symbol = get(g:, 'airline#extensions#lsp#error_symbol', 'E:')
+  let warning_symbol = get(g:, 'airline#extensions#lsp#warning_symbol', 'W:')
+  let show_line_numbers = get(g:, 'airline#extensions#lsp#show_line_numbers', 1)
+
+  let is_err = a:type ==# 'error'
+
+  let symbol = is_err ? error_symbol : warning_symbol
+
+  let num = lsp#get_buffer_diagnostics_counts()[a:type]
+
+  if show_line_numbers == 1
+    return s:airline_lsp_count(num, symbol) . <sid>airline_lsp_get_line_number(num, a:type)
+  else
+    return s:airline_lsp_count(num, symbol)
+  endif
+endfunction
+
+function! airline#extensions#lsp#get_warning() abort
+  return airline#extensions#lsp#get('warning')
+endfunction
+
+function! airline#extensions#lsp#get_error() abort
+  return airline#extensions#lsp#get('error')
+endfunction
+
+function! airline#extensions#lsp#init(ext) abort
+  call airline#parts#define_function('lsp_error_count', 'airline#extensions#lsp#get_error')
+  call airline#parts#define_function('lsp_warning_count', 'airline#extensions#lsp#get_warning')
+endfunction