From bbe9b034f07d345f9fea4c51b84dd1fba1c78851 Mon Sep 17 00:00:00 2001
From: Kim K <koomen@protonmail.com>
Date: Sun, 17 Feb 2019 12:53:01 +0100
Subject: [PATCH] feat: Implement equal pair detection

---
 README.md             | 29 +++++++++++++++++++++++++++++
 doc/AutoPairs.txt     | 38 ++++++++++++++++++++++++++++++++++++++
 plugin/auto-pairs.vim | 29 +++++++++++++++++++++++++++--
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index d467cf9..288116c 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,35 @@ Features
 
         }|
 
+*   Auto detect when to close by checking the equality of pairs within the buffer: >
+
+        input:
+            const user = getUser|id)
+
+        (press ( at |)
+
+        output:
+            const user = getUser(id)
+
+        ---
+
+        input:
+            |]]
+
+        (press [ at |)
+
+        output:
+            [|]]
+
+        (press [ at | again)
+
+        output:
+            [[|]]
+
+        (press [ at | again)
+
+        output:
+            [[[|]]]
 *  Fly Mode
 
         input: if(a[3)
diff --git a/doc/AutoPairs.txt b/doc/AutoPairs.txt
index afe589e..4607797 100644
--- a/doc/AutoPairs.txt
+++ b/doc/AutoPairs.txt
@@ -103,6 +103,35 @@ Support ```, ''' and """: >
         output:
             '''|'''
 
+Auto detect when to close by checking the equality of pairs within the buffer: >
+        input:
+            const user = getUser|id)
+
+        (press ( at |)
+
+        output:
+            const user = getUser(id)
+
+        ---
+
+        input:
+            |]]
+
+        (press [ at |)
+
+        output:
+            [|]]
+
+        (press [ at | again)
+
+        output:
+            [[|]]
+
+        (press [ at | again)
+
+        output:
+            [[[|]]]
+
 Delete Repeated Pairs in one time: >
 
         input: """|""" (press <BS> at |)
@@ -247,6 +276,15 @@ Default: <M-n>
 Jump to the next closed pair.
 
 
+                                                *g:AutoPairsEqualPairDetection*
+|g:AutoPairsEqualPairDetection|                                             int
+
+Default: 1
+
+Detects when to close a pair by detecting the equality of pairs within the
+current buffer. (This feature is not supported for multibyte pairs)
+
+
                                                 *g:AutoPairsShortcutBackInsert*
 |g:AutoPairsShortcutBackInsert|                                          string
 
diff --git a/plugin/auto-pairs.vim b/plugin/auto-pairs.vim
index e630454..d58022b 100644
--- a/plugin/auto-pairs.vim
+++ b/plugin/auto-pairs.vim
@@ -79,6 +79,10 @@ if !exists('g:AutoPairsShortcutJump')
   let g:AutoPairsShortcutJump = '<M-n>'
 endif
 
+if !exists('g:AutoPairsEqualPairDetection')
+  let g:AutoPairsEqualPairDetection = 1
+endif
+
 " Fly mode will for closed pair to jump to closed pair instead of insert.
 " also support AutoPairsBackInsert to insert pairs where jumped.
 if !exists('g:AutoPairsFlyMode')
@@ -195,6 +199,20 @@ func! AutoPairsDefine(pairs, ...)
   return r
 endf
 
+func! s:count(word)
+  " Because of the substitution the cursor is moved when there are matches and
+  " thus we have to preserve the cursor position.
+  let cpos = [line('.'), col('.')]
+  try
+    let result = execute('%s/\V' . a:word . '//gn')
+    call cursor(cpos)
+    let occurences = trim(strpart(result, 0, stridx(result, " ")))
+    return occurences
+  catch
+    return 0
+  endtry
+endfunction
+
 func! AutoPairsInsert(key)
   if !b:autopairs_enabled
     return a:key
@@ -246,7 +264,7 @@ func! AutoPairsInsert(key)
           end
         endfor
         if !found
-          " delete charactor
+          " delete character
           let ms = s:matchend(before, '\v.')
           if len(ms)
             let before = ms[1]
@@ -254,7 +272,14 @@ func! AutoPairsInsert(key)
           end
         end
       endwhile
-      return bs.del.openPair.close.s:left(close)
+
+      if strlen(open) == 1 && g:AutoPairsEqualPairDetection == 1
+        if s:count(open) == s:count(close)
+          return bs.del.openPair.close.s:left(close)
+        endif
+      else
+        return bs.del.openPair.close.s:left(close)
+      endif
     end
   endfor