From 38fa9f976c2d920c2fb1e11d5be5d702f7198217 Mon Sep 17 00:00:00 2001
From: xwii <wangrongfei0218@outlook.com>
Date: Sat, 14 Jan 2023 01:33:13 +0700
Subject: [PATCH] Use `table.move` to implement `common.splice` (#1324)

* Use `table.move` to implement `common.splice`

* Disallow negative `remove` in `common.splice`
---
 data/core/common.lua | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/data/core/common.lua b/data/core/common.lua
index a4ea01f5..b6c9db67 100644
--- a/data/core/common.lua
+++ b/data/core/common.lua
@@ -82,25 +82,14 @@ end
 
 
 function common.splice(t, at, remove, insert)
+  assert(remove >= 0, "bad argument #3 to 'splice' (non-negative value expected)")
   insert = insert or {}
-  local offset = #insert - remove
-  local old_len = #t
-  if offset < 0 then
-    for i = at - offset, old_len - offset do
-      t[i + offset] = t[i]
-    end
-  elseif offset > 0 then
-    for i = old_len, at, -1 do
-      t[i + offset] = t[i]
-    end
-  end
-  for i, item in ipairs(insert) do
-    t[at + i - 1] = item
-  end
+  local len = #insert
+  if remove ~= len then table.move(t, at + remove, #t + remove, at + len) end
+  table.move(insert, 1, len, at, t)
 end
 
 
-
 local function compare_score(a, b)
   return a.score > b.score
 end