Merge branch 'master' into not-yieldable

27 files changed, 380 insertions, 144 deletions

diff --git a/script/client.lua b/script/client.lua
index 4d338016..4d39cd0d 100644
--- a/script/client.lua
+++ b/script/client.lua
@@ -59,6 +59,23 @@ function m.getAbility(name)
     return current
 end
 
+function m.getOffsetEncoding()
+    if m._offsetEncoding then
+        return m._offsetEncoding
+    end
+    local clientEncodings = m.getAbility 'offsetEncoding'
+    if type(clientEncodings) == 'table' then
+        for _, encoding in ipairs(clientEncodings) do
+            if encoding == 'utf-8' then
+                m._offsetEncoding = 'utf-8'
+                return m._offsetEncoding
+            end
+        end
+    end
+    m._offsetEncoding = 'utf-16'
+    return m._offsetEncoding
+end
+
 local function packMessage(...)
     local strs = table.pack(...)
     for i = 1, strs.n do
@@ -255,6 +272,7 @@ function m.init(t)
     m.client(t.clientInfo.name)
     nonil.disable()
     lang(LOCALE or t.locale)
+    converter.setOffsetEncoding(m.getOffsetEncoding())
     hookPrint()
 end
 
diff --git a/script/config/loader.lua b/script/config/loader.lua
index 03588634..e754be49 100644
--- a/script/config/loader.lua
+++ b/script/config/loader.lua
@@ -19,37 +19,43 @@ local m = {}
 function m.loadRCConfig(filename)
     local path = workspace.getAbsolutePath(filename)
     if not path then
-        return
+        m.lastRCConfig = nil
+        return nil
     end
     local buf = util.loadFile(path)
     if not buf then
-        return
+        m.lastRCConfig = nil
+        return nil
     end
     local suc, res = pcall(json.decode, buf)
     if not suc then
         errorMessage(lang.script('CONFIG_LOAD_ERROR', res))
-        return
+        return m.lastRCConfig
     end
+    m.lastRCConfig = res
     return res
 end
 
 function m.loadLocalConfig(filename)
     local path = workspace.getAbsolutePath(filename)
     if not path then
-        return
+        m.lastLocalConfig = nil
+        return nil
     end
     local buf  = util.loadFile(path)
     if not buf then
         errorMessage(lang.script('CONFIG_LOAD_FAILED', path))
-        return
+        m.lastLocalConfig = nil
+        return nil
     end
     local firstChar = buf:match '%S'
     if firstChar == '{' then
         local suc, res = pcall(json.decode, buf)
         if not suc then
             errorMessage(lang.script('CONFIG_LOAD_ERROR', res))
-            return
+            return m.lastLocalConfig
         end
+        m.lastLocalConfig = res
         return res
     else
         local suc, res = pcall(function ()
@@ -57,8 +63,9 @@ function m.loadLocalConfig(filename)
         end)
         if not suc then
             errorMessage(lang.script('CONFIG_LOAD_ERROR', res))
-            return
+            return m.lastLocalConfig
         end
+        m.lastLocalConfig = res
         return res
     end
 end
diff --git a/script/core/completion.lua b/script/core/completion.lua
index e30c9c91..b7de7578 100644
--- a/script/core/completion.lua
+++ b/script/core/completion.lua
@@ -718,7 +718,8 @@ end
 
 local function isInString(state, position)
     return guide.eachSourceContain(state.ast, position, function (source)
-        if source.type == 'string' then
+        if  source.type == 'string'
+        and source.start  < position then
             return true
         end
     end)
@@ -1629,6 +1630,7 @@ local function tryLuaDocCate(word, results)
         'diagnostic',
         'module',
         'async',
+        'nodiscard',
     } do
         if matchKey(word, docType) then
             results[#results+1] = {
diff --git a/script/core/diagnostics/await-in-sync.lua b/script/core/diagnostics/await-in-sync.lua
index bfb4af38..558a5ff0 100644
--- a/script/core/diagnostics/await-in-sync.lua
+++ b/script/core/diagnostics/await-in-sync.lua
@@ -4,25 +4,27 @@ local vm    = require 'vm'
 local lang  = require 'language'
 local await = require 'await'
 
+---@async
 return function (uri, callback)
     local state = files.getState(uri)
     if not state then
         return
     end
 
-    guide.eachSourceType(state.ast, 'call', function (source) ---@async
+    ---@async
+    guide.eachSourceType(state.ast, 'call', function (source)
         local currentFunc = guide.getParentFunction(source)
         if currentFunc and vm.isAsync(currentFunc, false) then
             return
         end
         await.delay()
-        if not vm.isAsync(source.node, true) then
+        if vm.isAsyncCall(source) then
+            callback {
+                start   = source.node.start,
+                finish  = source.node.finish,
+                message = lang.script('DIAG_AWAIT_IN_SYNC'),
+            }
             return
         end
-        callback {
-            start   = source.node.start,
-            finish  = source.node.finish,
-            message = lang.script('DIAG_AWAIT_IN_SYNC'),
-        }
     end)
 end
diff --git a/script/core/diagnostics/deprecated.lua b/script/core/diagnostics/deprecated.lua
index 7cd9e00f..e9a1fef7 100644
--- a/script/core/diagnostics/deprecated.lua
+++ b/script/core/diagnostics/deprecated.lua
@@ -8,6 +8,7 @@ local await    = require 'await'
 local noder    = require 'core.noder'
 
 local types = {'getglobal', 'getfield', 'getindex', 'getmethod'}
+---@async
 return function (uri, callback)
     local ast = files.getState(uri)
     if not ast then
diff --git a/script/core/diagnostics/discard-returns.lua b/script/core/diagnostics/discard-returns.lua
new file mode 100644
index 00000000..cef7ece5
--- /dev/null
+++ b/script/core/diagnostics/discard-returns.lua
@@ -0,0 +1,29 @@
+local files = require 'files'
+local guide = require 'parser.guide'
+local vm    = require 'vm'
+local await = require 'await'
+local lang  = require 'language'
+
+---@async
+return function (uri, callback)
+    local state = files.getState(uri)
+    if not state then
+        return
+    end
+    ---@async
+    guide.eachSourceType(state.ast, 'call', function (source)
+        local parent = source.parent
+        if  parent.type ~= 'function'
+        and parent.type ~= 'main' then
+            return
+        end
+        await.delay()
+        if vm.isNoDiscard(source.node, true) then
+            callback {
+                start   = source.start,
+                finish  = source.finish,
+                message = lang.script('DIAG_DISCARD_RETURNS'),
+            }
+        end
+    end)
+end
diff --git a/script/core/diagnostics/redundant-value.lua b/script/core/diagnostics/redundant-value.lua
index edead570..6f60303b 100644
--- a/script/core/diagnostics/redundant-value.lua
+++ b/script/core/diagnostics/redundant-value.lua
@@ -4,6 +4,7 @@ local lang   = require 'language'
 local guide  = require 'parser.guide'
 local await  = require 'await'
 
+---@async
 return function (uri, callback)
     local state = files.getState(uri)
     if not state then
diff --git a/script/core/diagnostics/type-check.lua b/script/core/diagnostics/type-check.lua
index 3fa5050c..8728b169 100644
--- a/script/core/diagnostics/type-check.lua
+++ b/script/core/diagnostics/type-check.lua
@@ -412,6 +412,7 @@ local function matchParams(paramsTypes, i, arg)
     return false, messages
 end
 
+---@async
 return function (uri, callback)
     local ast = files.getState(uri)
     if not ast then
diff --git a/script/core/diagnostics/undefined-field.lua b/script/core/diagnostics/undefined-field.lua
index 66b1f8c5..2e64f0cc 100644
--- a/script/core/diagnostics/undefined-field.lua
+++ b/script/core/diagnostics/undefined-field.lua
@@ -18,6 +18,7 @@ local SkipCheckClass = {
     ['lightuserdata'] = true,
 }
 
+---@async
 return function (uri, callback)
     local ast = files.getState(uri)
     if not ast then
diff --git a/script/core/diagnostics/undefined-global.lua b/script/core/diagnostics/undefined-global.lua
index 640f521b..48c8a226 100644
--- a/script/core/diagnostics/undefined-global.lua
+++ b/script/core/diagnostics/undefined-global.lua
@@ -14,6 +14,7 @@ local requireLike = {
     ['load']    = true,
 }
 
+---@async
 return function (uri, callback)
     local ast = files.getState(uri)
     if not ast then
diff --git a/script/core/diagnostics/unused-function.lua b/script/core/diagnostics/unused-function.lua
index ada4a23d..0e0c0003 100644
--- a/script/core/diagnostics/unused-function.lua
+++ b/script/core/diagnostics/unused-function.lua
@@ -18,6 +18,7 @@ local function isToBeClosed(source)
     return false
 end
 
+---@async
 return function (uri, callback)
     local ast = files.getState(uri)
     if not ast then
diff --git a/script/core/document-symbol.lua b/script/core/document-symbol.lua
index 00299867..07794e60 100644
--- a/script/core/document-symbol.lua
+++ b/script/core/document-symbol.lua
@@ -235,6 +235,7 @@ local function buildSource(source, text, used, symbols)
     end
 end
 
+---@async
 local function makeSymbol(uri)
     local ast = files.getState(uri)
     local text = files.getText(uri)
diff --git a/script/core/hint.lua b/script/core/hint.lua
index e094fc51..42390443 100644
--- a/script/core/hint.lua
+++ b/script/core/hint.lua
@@ -6,6 +6,7 @@ local guide    = require 'parser.guide'
 local await    = require 'await'
 local define   = require 'proto.define'
 
+---@async
 local function typeHint(uri, results, start, finish)
     local state = files.getState(uri)
     if not state then
@@ -96,6 +97,7 @@ local function hasLiteralArgInCall(call)
     return false
 end
 
+---@async
 local function paramName(uri, results, start, finish)
     local paramConfig = config.get 'Lua.hint.paramName'
     if not paramConfig or paramConfig == 'None' then
@@ -158,6 +160,7 @@ local function paramName(uri, results, start, finish)
     end)
 end
 
+---@async
 local function awaitHint(uri, results, start, finish)
     local awaitConfig = config.get 'Lua.hint.await'
     if not awaitConfig then
@@ -173,7 +176,7 @@ local function awaitHint(uri, results, start, finish)
         end
         await.delay()
         local node = source.node
-        if not vm.isAsync(node, true) then
+        if not vm.isAsyncCall(source) then
             return
         end
         results[#results+1] = {
@@ -185,6 +188,7 @@ local function awaitHint(uri, results, start, finish)
     end)
 end
 
+---@async
 return function (uri, start, finish)
     local results = {}
     typeHint(uri, results, start, finish)
diff --git a/script/core/semantic-tokens.lua b/script/core/semantic-tokens.lua
index aef28aa6..8389cbb4 100644
--- a/script/core/semantic-tokens.lua
+++ b/script/core/semantic-tokens.lua
@@ -373,6 +373,7 @@ config.watch(function (key, value)
     end
 end)
 
+---@async
 return function (uri, start, finish)
     local state = files.getState(uri)
     local text  = files.getText(uri)
diff --git a/script/encoder/ansi.lua b/script/encoder/ansi.lua
index 1016e668..f5273c51 100644
--- a/script/encoder/ansi.lua
+++ b/script/encoder/ansi.lua
@@ -7,14 +7,14 @@ end
 
 local m = {}
 
-function m.decode(text)
+function m.toutf8(text)
     if not unicode then
         return text
     end
     return unicode.a2u(text)
 end
 
-function m.encode(text)
+function m.fromutf8(text)
     if not unicode then
         return text
     end
diff --git a/script/encoder/init.lua b/script/encoder/init.lua
index d7753c1f..0011265a 100644
--- a/script/encoder/init.lua
+++ b/script/encoder/init.lua
@@ -1,6 +1,7 @@
 local ansi    = require 'encoder.ansi'
-local utf16le = require 'encoder.utf16le'
-local utf16be = require 'encoder.utf16be'
+local utf16   = require 'encoder.utf16'
+local utf16le = utf16('le', utf8.codepoint '�')
+local utf16be = utf16('be', utf8.codepoint '�')
 
 ---@alias encoder.encoding '"utf8"'|'"utf16"'|'"utf16le"'|'"utf16be"'
 
@@ -17,11 +18,11 @@ function m.len(encoding, s, i, j)
     j = j or #s
     if encoding == 'utf16'
     or encoding == 'utf16' then
-        local us = utf16le.encode(s:sub(i, j))
+        local us = utf16le.fromutf8(s:sub(i, j))
         return #us // 2
     end
     if encoding == 'utf16be' then
-        local us = utf16be.encode(s:sub(i, j))
+        local us = utf16be.fromutf8(s:sub(i, j))
         return #us // 2
     end
     if encoding == 'utf8' then
@@ -43,8 +44,8 @@ function m.offset(encoding, s, n, i)
         if not line:find '[\x80-\xff]' then
             return n + i - 1
         end
-        local us = utf16le.encode(line)
-        local os = utf16le.decode(us:sub(1, n * 2 - 2))
+        local us = utf16le.fromutf8(line)
+        local os = utf16le.toutf8(us:sub(1, n * 2 - 2))
         return #os + i
     end
     if encoding == 'utf16be' then
@@ -52,8 +53,8 @@ function m.offset(encoding, s, n, i)
         if not line:find '[\x80-\xff]' then
             return n + i - 1
         end
-        local us = utf16be.encode(line)
-        local os = utf16be.decode(us:sub(1, n * 2 - 2))
+        local us = utf16be.fromutf8(line)
+        local os = utf16be.toutf8(us:sub(1, n * 2 - 2))
         return #os + i
     end
     if encoding == 'utf8' then
@@ -75,11 +76,11 @@ function m.encode(encoding, text, bom)
         return text
     end
     if encoding == 'ansi' then
-        return ansi.encode(text)
+        return ansi.fromutf8(text)
     end
     if encoding == 'utf16'
     or encoding == 'utf16le' then
-        text = utf16le.encode(text)
+        text = utf16le.fromutf8(text)
         if bom == 'yes'
         or bom == 'auto' then
             text = '\xFF\xFE' .. text
@@ -87,7 +88,7 @@ function m.encode(encoding, text, bom)
         return text
     end
     if encoding == 'utf16be' then
-        text = utf16be.encode(text)
+        text = utf16be.fromutf8(text)
         if bom == 'yes'
         or bom == 'auto' then
             text = '\xFE\xFF' .. text
@@ -106,14 +107,14 @@ function m.decode(encoding, text)
         return text
     end
     if encoding == 'ansi' then
-        return ansi.decode(text)
+        return ansi.toutf8(text)
     end
     if encoding == 'utf16'
     or encoding == 'utf16le' then
-        return utf16le.decode(text)
+        return utf16le.toutf8(text)
     end
     if encoding == 'utf16be' then
-        return utf16be.decode(text)
+        return utf16be.toutf8(text)
     end
     log.error('Unsupport encode encoding:', encoding)
     return text
diff --git a/script/encoder/utf16.lua b/script/encoder/utf16.lua
new file mode 100644
index 00000000..9e71de68
--- /dev/null
+++ b/script/encoder/utf16.lua
@@ -0,0 +1,147 @@
+local error = error
+local strchar = string.char
+local strbyte = string.byte
+local strmatch = string.match
+local utf8char = utf8.char
+local tconcat = table.concat
+
+local function be_tochar(code)
+    return strchar((code >> 8) & 0xFF, code & 0xFF)
+end
+
+local function be_tobyte(s, i)
+    local h, l = strbyte(s, i, i+1)
+    return (h << 8) | l
+end
+
+local function le_tochar(code)
+    return strchar(code & 0xFF, (code >> 8) & 0xFF)
+end
+
+local function le_tobyte(s, i)
+    local l, h = strbyte(s, i, i+1)
+    return (h << 8) | l
+end
+
+local function utf16char(tochar, code)
+    if code < 0x10000 then
+        return tochar(code)
+    else
+        code = code - 0x10000
+        return tochar(0xD800 + (code >> 10))..tochar(0xDC00 + (code & 0x3FF))
+    end
+end
+
+local function utf16next(s, n, tobyte)
+    if n > #s then
+        return
+    end
+    local code1 = tobyte(s, n)
+    if code1 < 0xD800 or code1 >= 0xE000 then
+        return n+2, code1
+    elseif code1 >= 0xD800 and code1 < 0xDC00 then
+        n = n + 2
+        if n > #s then
+            return n --invaild
+        end
+        local code2 = tobyte(s, n)
+        if code2 < 0xDC00 or code2 >= 0xE000 then
+            return n --invaild
+        end
+        local code = 0x10000 + ((code1 - 0xD800) << 10) + ((code2 - 0xDC00) & 0x3FF)
+        return n+2, code
+    else
+        return n+2 --invaild
+    end
+end
+
+local function utf16codes(s, tobyte)
+    return function (_, n)
+        return utf16next(s, n, tobyte)
+    end, s, 1
+end
+
+local _utf8byte = utf8.codes ""
+local function utf8byte(s, n)
+    local _, code = _utf8byte(s, n-1)
+    return code
+end
+
+--[[
+  U+0000..  U+007F 00..7F
+  U+0080..  U+07FF C2..DF 80..BF
+  U+0800..  U+0FFF E0     A0..BF 80..BF
+  U+1000..  U+CFFF E1..EC 80..BF 80..BF
+  U+D000..  U+D7FF ED     80..9F 80..BF
+  U+E000..  U+FFFF EE..EF 80..BF 80..BF
+ U+10000.. U+3FFFF F0     90..BF 80..BF 80..BF
+ U+40000.. U+FFFFF F1..F3 80..BF 80..BF 80..BF
+U+100000..U+10FFFF F4     80..8F 80..BF 80..BF
+]]
+local function utf8next(s, n)
+    if n > #s then
+        return
+    end
+    if strmatch(s, "^[\0-\x7F]", n) then
+        return n+1, utf8byte(s, n)
+    elseif strmatch(s, "^[\xC2-\xDF][\x80-\xBF]", n) then
+        return n+2, utf8byte(s, n)
+    elseif strmatch(s, "^[\xE0-\xEF][\x80-\xBF][\x80-\xBF]", n) then
+        return n+3, utf8byte(s, n)
+    elseif strmatch(s, "^[\xF0-\xF4][\x80-\xBF][\x80-\xBF][\x80-\xBF]", n) then
+        return n+4, utf8byte(s, n)
+    else
+        return n+1 --invaild
+    end
+end
+
+local function utf8codes(s)
+    return utf8next, s, 1
+end
+
+return function (what, replace)
+    local tobyte, tochar
+    if what == "be" then
+        tobyte = be_tobyte
+        tochar = be_tochar
+    else
+        tobyte = le_tobyte
+        tochar = le_tochar
+    end
+    local utf8replace  = replace and utf8char(replace)
+    local utf16replace = replace and utf16char(tochar, replace)
+    local function toutf8(s)
+        local r = {}
+        for _, code in utf16codes(s, tobyte) do
+            if code == nil then
+                if replace then
+                    r[#r+1] = utf8replace
+                else
+                    error "invalid UTF-16 code"
+                end
+            else
+                r[#r+1] = utf8char(code)
+            end
+        end
+        return tconcat(r)
+    end
+    local function fromutf8(s)
+        local r = {}
+        for _, code in utf8codes(s) do
+            if code == nil then
+                if replace then
+                    r[#r+1] = utf16replace
+                else
+                    error "invalid UTF-8 code"
+                end
+            else
+                r[#r+1] = utf16char(tochar, code)
+            end
+        end
+        return tconcat(r)
+    end
+    return {
+        toutf8 = toutf8,
+        fromutf8 = fromutf8,
+    }
+end
diff --git a/script/encoder/utf16be.lua b/script/encoder/utf16be.lua
deleted file mode 100644
index 5fc19b2c..00000000
--- a/script/encoder/utf16be.lua
+++ /dev/null
@@ -1,46 +0,0 @@
-local function tochar(code)
-    return string.char((code >> 8) & 0xFF, code & 0xFF)
-end
-
-local function tobyte(s, i)
-    local h, l = string.byte(s, i, i+1)
-    return (h << 8) | l
-end
-
-local function char(code)
-    if code <= 0xFFFF then
-        return tochar(code)
-    end
-    code = code - 0x10000
-    return tochar(0xD800 + (code >> 10))..tochar(0xDC00 + (code & 0x3FF))
-end
-
-local m = {}
-
-function m.encode(s)
-    local r = {}
-    for _, c in utf8.codes(s, true) do
-        r[#r+1] = char(c)
-    end
-    return table.concat(r)
-end
-
-function m.decode(s)
-    local r = {}
-    local i = 1
-    while i < #s do
-        local code1 = tobyte(s, i)
-        if code1 >= 0xD800 and code1 < 0xE000 then
-            i = i + 2
-            local code2 = tobyte(s, i)
-            local code = 0x10000 + ((code1 - 0xD800) << 10) + ((code2 - 0xDC00) & 0x3FF)
-            r[#r+1] = utf8.char(code)
-        else
-            r[#r+1] = utf8.char(code1)
-        end
-        i = i + 2
-    end
-    return table.concat(r)
-end
-
-return m
diff --git a/script/encoder/utf16le.lua b/script/encoder/utf16le.lua
deleted file mode 100644
index d51b4cfb..00000000
--- a/script/encoder/utf16le.lua
+++ /dev/null
@@ -1,46 +0,0 @@
-local function tochar(code)
-    return string.char(code & 0xFF, (code >> 8) & 0xFF)
-end
-
-local function tobyte(s, i)
-    local l, h = string.byte(s, i, i+1)
-    return (h << 8) | l
-end
-
-local function char(code)
-    if code <= 0xFFFF then
-        return tochar(code)
-    end
-    code = code - 0x10000
-    return tochar(0xD800 + (code >> 10))..tochar(0xDC00 + (code & 0x3FF))
-end
-
-local m = {}
-
-function m.encode(s)
-    local r = {}
-    for _, c in utf8.codes(s, true) do
-        r[#r+1] = char(c)
-    end
-    return table.concat(r)
-end
-
-function m.decode(s)
-    local r = {}
-    local i = 1
-    while i < #s do
-        local code1 = tobyte(s, i)
-        if code1 >= 0xD800 and code1 < 0xE000 then
-            i = i + 2
-            local code2 = tobyte(s, i)
-            local code = 0x10000 + ((code1 - 0xD800) << 10) + ((code2 - 0xDC00) & 0x3FF)
-            r[#r+1] = utf8.char(code)
-        else
-            r[#r+1] = utf8.char(code1)
-        end
-        i = i + 2
-    end
-    return table.concat(r)
-end
-
-return m
diff --git a/script/files.lua b/script/files.lua
index 9b22ea41..eca3d58d 100644
--- a/script/files.lua
+++ b/script/files.lua
@@ -120,7 +120,9 @@ end
 --- 设置文件文本
 ---@param uri uri
 ---@param text string
-function m.setText(uri, text, isTrust)
+---@param isTrust boolean
+---@param version integer
+function m.setText(uri, text, isTrust, version)
     if not text then
         return
     end
@@ -134,7 +136,6 @@ function m.setText(uri, text, isTrust)
     if not m.fileMap[uri] then
         m.fileMap[uri] = {
             uri = uri,
-            version = 0,
         }
         m.fileCount = m.fileCount + 1
         create = true
@@ -159,7 +160,7 @@ function m.setText(uri, text, isTrust)
     m.astMap[uri] = nil
     file.cache = {}
     file.cacheActiveTime = math.huge
-    file.version = file.version + 1
+    file.version = version
     m.globalVersion = m.globalVersion + 1
     await.close('files.version')
     m.onWatch('version')
diff --git a/script/parser/luadoc.lua b/script/parser/luadoc.lua
index 6f7593c1..c332d4c0 100644
--- a/script/parser/luadoc.lua
+++ b/script/parser/luadoc.lua
@@ -1119,6 +1119,14 @@ local function parseAsync()
     }
 end
 
+local function parseNoDiscard()
+    return {
+        type   = 'doc.nodiscard',
+        start  = getFinish(),
+        finish = getFinish(),
+    }
+end
+
 local function convertTokens()
     local tp, text = nextToken()
     if not tp then
@@ -1164,6 +1172,8 @@ local function convertTokens()
         return parseModule()
     elseif text == 'async' then
         return parseAsync()
+    elseif text == 'nodiscard' then
+        return parseNoDiscard()
     end
 end
 
diff --git a/script/proto/converter.lua b/script/proto/converter.lua
index cf6331f1..9c75f056 100644
--- a/script/proto/converter.lua
+++ b/script/proto/converter.lua
@@ -2,7 +2,6 @@ local guide   = require 'parser.guide'
 local files   = require 'files'
 local encoder = require 'encoder'
 
--- TODO
 local offsetEncoding = 'utf16'
 
 local m = {}
@@ -178,4 +177,8 @@ function m.textEdit(range, newtext)
     }
 end
 
+function m.setOffsetEncoding(encoding)
+    offsetEncoding = encoding:lower():gsub('%-', '')
+end
+
 return m
diff --git a/script/proto/define.lua b/script/proto/define.lua
index e4216be1..dbb6ba85 100644
--- a/script/proto/define.lua
+++ b/script/proto/define.lua
@@ -46,6 +46,7 @@ m.DiagnosticDefaultSeverity = {
     ['different-requires']      = 'Warning',
     ['await-in-sync']           = 'Warning',
     ['not-yieldable']           = 'Warning',
+    ['discard-returns']         = 'Warning',
     ['type-check']              = 'Warning',
 
     ['duplicate-doc-class']     = 'Warning',
@@ -102,6 +103,7 @@ m.DiagnosticDefaultNeededFileStatus = {
     ['different-requires']      = 'Any',
     ['await-in-sync']           = 'None',
     ['not-yieldable']           = 'None',
+    ['discard-returns']         = 'Opened',
     ['type-check']              = 'None',
 
     ['duplicate-doc-class']     = 'Any',
diff --git a/script/provider/capability.lua b/script/provider/capability.lua
index 76cadc0d..b712defc 100644
--- a/script/provider/capability.lua
+++ b/script/provider/capability.lua
@@ -48,6 +48,7 @@ end
 
 function m.getIniter()
     local initer = {
+        offsetEncoding = client.getOffsetEncoding(),
         -- 文本同步方式
         textDocumentSync = {
             -- 打开关闭文本时通知
diff --git a/script/provider/diagnostic.lua b/script/provider/diagnostic.lua
index 34bb10d4..c8d6c211 100644
--- a/script/provider/diagnostic.lua
+++ b/script/provider/diagnostic.lua
@@ -216,6 +216,8 @@ function m.doDiagnostic(uri)
         return
     end
 
+    local version = files.getVersion(uri)
+
     await.setID('diag:' .. uri)
 
     local prog <close> = progress.create(lang.script.WINDOW_DIAGNOSING, 0.5)
@@ -239,6 +241,7 @@ function m.doDiagnostic(uri)
 
         proto.notify('textDocument/publishDiagnostics', {
             uri = uri,
+            version = version,
             diagnostics = full,
         })
         if #full > 0 then
diff --git a/script/provider/provider.lua b/script/provider/provider.lua
index 811dc4e0..36752d88 100644
--- a/script/provider/provider.lua
+++ b/script/provider/provider.lua
@@ -185,7 +185,7 @@ proto.on('textDocument/didChange', function (params) ---@async
     local uri     = doc.uri
     --log.debug('changes', util.dump(changes))
     local text = tm(uri, changes)
-    files.setText(uri, text, true)
+    files.setText(uri, text, true, doc.version)
 end)
 
 proto.on('textDocument/hover', function (params) ---@async
@@ -834,14 +834,14 @@ do
         if not config.get 'Lua.hint.enable' then
             return
         end
-        await.close 'updateHint'
-        await.setID 'updateHint'
-        await.delay()
-        workspace.awaitReady()
         local visibles = files.getVisibles(uri)
         if not visibles then
             return
         end
+        await.close 'updateHint'
+        await.setID 'updateHint'
+        await.delay()
+        workspace.awaitReady()
         local edits = {}
         local hint = require 'core.hint'
         local _ <close> = progress.create(lang.script.WINDOW_PROCESSING_HINT, 0.5)
diff --git a/script/vm/getDocs.lua b/script/vm/getDocs.lua
index ed2299ec..f5c4e4e1 100644
--- a/script/vm/getDocs.lua
+++ b/script/vm/getDocs.lua
@@ -163,6 +163,23 @@ local function isDeprecated(value)
     return false
 end
 
+function vm.isDeprecated(value, deep)
+    if deep then
+        local defs = vm.getDefs(value)
+        if #defs == 0 then
+            return false
+        end
+        for _, def in ipairs(defs) do
+            if not isDeprecated(def) then
+                return false
+            end
+        end
+        return true
+    else
+        return isDeprecated(value)
+    end
+end
+
 local function isAsync(value)
     if value.type == 'function' then
         if not value.bindDocs then
@@ -183,38 +200,111 @@ local function isAsync(value)
     return value.async == true
 end
 
-function vm.isDeprecated(value, deep)
+function vm.isAsync(value, deep)
+    if isAsync(value) then
+        return true
+    end
     if deep then
         local defs = vm.getDefs(value)
         if #defs == 0 then
             return false
         end
         for _, def in ipairs(defs) do
-            if not isDeprecated(def) then
-                return false
+            if isAsync(def) then
+                return true
             end
         end
-        return true
-    else
-        return isDeprecated(value)
     end
+    return false
 end
 
-function vm.isAsync(value, deep)
+local function isNoDiscard(value)
+    if value.type == 'function' then
+        if not value.bindDocs then
+            return false
+        end
+        if value._nodiscard ~= nil then
+            return value._nodiscard
+        end
+        for _, doc in ipairs(value.bindDocs) do
+            if doc.type == 'doc.nodiscard' then
+                value._nodiscard = true
+                return true
+            end
+        end
+        value._nodiscard = false
+        return false
+    end
+    return false
+end
+
+function vm.isNoDiscard(value, deep)
+    if isNoDiscard(value) then
+        return true
+    end
     if deep then
         local defs = vm.getDefs(value)
         if #defs == 0 then
             return false
         end
         for _, def in ipairs(defs) do
-            if isAsync(def) then
+            if isNoDiscard(def) then
                 return true
             end
         end
-        return false
-    else
-        return isAsync(value)
     end
+    return false
+end
+
+local function isCalledInFunction(param)
+    local func = guide.getParentFunction(param)
+    for _, ref in ipairs(param.ref) do
+        if ref.type == 'getlocal' then
+            if  ref.parent.type == 'call'
+            and guide.getParentFunction(ref) == func then
+                return true
+            end
+            if  ref.parent.type == 'callargs'
+            and ref.parent[1] == ref
+            and guide.getParentFunction(ref) == func then
+                if ref.parent.parent.node.special == 'pcall'
+                or ref.parent.parent.node.special == 'xpcall' then
+                    return true
+                end
+            end
+        end
+    end
+    return false
+end
+
+local function isLinkedCall(node, index)
+    for _, def in ipairs(vm.getDefs(node)) do
+        if def.type == 'function' then
+            local param = def.args and def.args[index]
+            if param then
+                if isCalledInFunction(param) then
+                    return true
+                end
+            end
+        end
+    end
+    return false
+end
+
+function vm.isAsyncCall(call)
+    if vm.isAsync(call.node, true) then
+        return true
+    end
+    if not call.args then
+        return
+    end
+    for i, arg in ipairs(call.args) do
+        if  vm.isAsync(arg, true)
+        and isLinkedCall(call.node, i) then
+            return true
+        end
+    end
+    return false
 end
 
 local function makeDiagRange(uri, doc, results)