Add option to enable smart case matching.

Author: kristijanhusak

README.md

@@ -207,6 +207,10 @@ work as you expect on some language server.
 ```vim
 g:completion_matching_ignore_case = 1
 ```
+- Or smart case matching by
+```vim
+g:completion_matching_smart_case = 1
+```
 
 ### Trigger Characters
 

doc/completion-nvim.txt

@@ -63,9 +63,9 @@ g:completion_enable_auto_popup               *g:completion_enable_auto_popup*
 	this value to 0 if you don't want automatically popup window.
 
 	If you disable auto popup menu, you can manually trigger completion by
-	mapping keys. For example: 
+	mapping keys. For example:
 >
-        " map <c-p> to manually trigger completion 
+        " map <c-p> to manually trigger completion
         imap <silent> <c-p> <Plug>(completion_trigger)
 <
         Or you want to use <tab> to trigger completion without modifying the
@@ -157,7 +157,7 @@ g:completion_trigger_character                *g:completion_trigger_character*
         default value: ['.']
 
 g:completion_trigger_keyword_length		    *g:completion_trigger_keyword_length*
-	
+
 	You can specify keyword length for triggering completion, if the
 	current word is less than keyword length, completion won't be
 	triggered.
@@ -277,7 +277,7 @@ g:completion_chain_complete_list	    *g:completion_chain_complete_list*
 <
 	You can take a step further to specify different 'scope' of different
 	filetypes. 'scope' is literally syntax in your file. Say that you want
-	different completion lists in comments and function calls, strings, 
+	different completion lists in comments and function calls, strings,
 	etc, you can do that easily. Here is an example
 >
 	let g:completion_chain_complete_list = {
@@ -346,15 +346,23 @@ g:completion_matching_strategy_list	*g:completion_matching_strategy_list*
 	default value: ['exact']
 
 g:completion_matching_ignore_case	*g:completion_matching_ignore_case*
-	
+
 	Enable ignore case matching in all matching strategy. For example
 >
 	let g:completion_matching_ignore_case = 1
 <
 	default value: 0
 
+g:completion_matching_smart_case	*g:completion_matching_smart_case*
+
+	Enable smart case matching in all matching strategy. For example
+>
+	let g:completion_matching_smart_case = 1
+<
+	default value: 0
+
 g:completion_sorting				    *g:completion_sorting*
-	
+
 	You can determine how you want to sort the completion items in popup
 	menu. Possible values are 'alphabet', 'length', 'none'
 

lua/completion/matching.lua

@@ -3,11 +3,22 @@ local util = require 'completion.util'
 local opt = require 'completion.option'
 local M = {}
 
-local function fuzzy_match(prefix, word)
-  if opt.get_option('matching_ignore_case') == 1 then
-    prefix = string.lower(prefix)
-    word = string.lower(word)
+local function setup_case(prefix, word)
+  local ignore_case = opt.get_option('matching_ignore_case') == 1
+
+  if not ignore_case and opt.get_option('matching_smart_case') == 1 and not prefix:match('[A-Z]') then
+    ignore_case = true
   end
+
+  if ignore_case then
+    return string.lower(prefix), string.lower(word)
+  end
+
+  return prefix, word
+end
+
+local function fuzzy_match(prefix, word)
+  prefix, word = setup_case(prefix, word)
   local score = util.fuzzy_score(prefix, word)
   if score < 1 then
     return true, score
@@ -18,10 +29,7 @@ end
 
 
 local function substring_match(prefix, word)
-  if opt.get_option('matching_ignore_case') == 1 then
-    prefix = string.lower(prefix)
-    word = string.lower(word)
-  end
+  prefix, word = setup_case(prefix, word)
   if string.find(word, prefix) then
     return true
   else
@@ -30,10 +38,7 @@ local function substring_match(prefix, word)
 end
 
 local function exact_match(prefix, word)
-  if opt.get_option('matching_ignore_case') == 1 then
-    prefix = string.lower(prefix)
-    word = string.lower(word)
-  end
+  prefix, word = setup_case(prefix, word)
   if vim.startswith(word, prefix) then
     return true
   else

plugin/completion.vim

@@ -85,6 +85,10 @@ if ! exists('g:completion_matching_ignore_case')
     let g:completion_matching_ignore_case = 0
 endif
 
+if ! exists('g:completion_matching_smart_case')
+    let g:completion_matching_smart_case = 0
+endif
+
 if ! exists('g:completion_matching_strategy_list')
     let g:completion_matching_strategy_list = ['exact']
 endif