Add vim plugin coc.nvim segments. (#2057)

* Add vim plugin coc.nvim segments.

* Add coc highlight group to colorschemes: default, solarized, solarizedlight.

* Fix coc highlight group in colorschemes: solarized, solarizedlight.

* Add document for segments.vim.plugin.coc.coc

powerline/segments/vim/plugin/coc.py

@@ -0,0 +1,51 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+try:
+	import vim
+except ImportError:
+	vim = object()
+
+from powerline.bindings.vim import vim_command_exists
+from powerline.theme import requires_segment_info
+
+# coc_status's format: E1 W2
+def parse_coc_status(coc_status):
+	# type(coc_status) is tuple
+	errors_count = 0
+	warnings_count = 0
+	if len(coc_status) <= 0:
+		return errors_count, warnings_count
+	status_str = coc_status[0]
+	if len(status_str) <= 0:
+		return errors_count, warnings_count
+	status_list = status_str.split(' ')
+	for item in status_list:
+		if len(item) > 0 and item[0] == 'E':
+			errors_count = int(item[1:])
+		if len(item) > 0 and item[0] == 'W':
+			warnings_count = int(item[1:])
+	return errors_count, warnings_count
+
+@requires_segment_info
+def coc(segment_info, pl):
+	'''Show whether coc.nvim has found any errors or warnings
+
+	Highlight groups used: ``coc:warning`` or ``warning``, ``coc:error`` or ``error``.
+	'''
+	segments = []
+	if not vim_command_exists('CocCommand'):
+		return segments
+	coc_status = vim.eval('coc#status()'),
+	errors_count, warnings_count = parse_coc_status(coc_status)
+	if errors_count > 0:
+		segments.append({
+			'contents': 'E:' + str(errors_count),
+			'highlight_groups': ['coc:error', 'error'],
+		})
+	if warnings_count > 0:
+		segments.append({
+			'contents': 'W:' + str(warnings_count),
+			'highlight_groups': ['coc:warning', 'warning'],
+	})
+	return segments