9 files changed, 146 insertions, 2 deletions
diff --git a/server/src/emmy/manager.lua b/server/src/emmy/manager.lua
index fe14173c..d8b3b656 100644
--- a/server/src/emmy/manager.lua
+++ b/server/src/emmy/manager.lua
@@ -3,6 +3,7 @@ local newClass = require 'emmy.class'
 local newType = require 'emmy.type'
 local newTypeUnit = require 'emmy.typeUnit'
 local newAlias = require 'emmy.alias'
+local newParam = require 'emmy.param'
 
 local mt = {}
 mt.__index = mt
@@ -104,6 +105,15 @@ function mt:addAlias(source, typeObj)
     return aliasObj
 end
 
+function mt:addParam(source, typeObj)
+    local paramName = source[1][1]
+    local paramObj = newParam(self, source)
+    paramObj:bindType(typeObj)
+    local list = self:getClass(paramName)
+    list[source.id] = paramObj
+    return paramObj
+end
+
 function mt:remove()
 end
 
diff --git a/server/src/emmy/param.lua b/server/src/emmy/param.lua
new file mode 100644
index 00000000..9c18bfec
--- /dev/null
+++ b/server/src/emmy/param.lua
@@ -0,0 +1,31 @@
+local listMgr = require 'vm.list'
+
+---@class EmmyParam
+local mt = {}
+mt.__index = mt
+mt.type = 'emmy.param'
+
+function mt:getName()
+    return self.name
+end
+
+function mt:getSource()
+    return listMgr.get(self.source)
+end
+
+function mt:bindType(type)
+    if type then
+        self._bindType = type
+    else
+        return self._bindType
+    end
+end
+
+return function (manager, source)
+    local self = setmetatable({
+        name = source[1][1],
+        source = source.id,
+        _manager = manager,
+    }, mt)
+    return self
+end
diff --git a/server/src/parser/ast.lua b/server/src/parser/ast.lua
index 8c703491..7df7676d 100644
--- a/server/src/parser/ast.lua
+++ b/server/src/parser/ast.lua
@@ -629,7 +629,7 @@ local Defs = {
             end
             if isField then
                 table[#table+1] = arg
-                if arg.finish then
+                if arg.type:sub(1, 4) ~= 'emmy' then
                     wantField = false
                     start = arg.finish + 1
                 end
diff --git a/server/src/vm/emmy.lua b/server/src/vm/emmy.lua
index a2a38553..5406aab1 100644
--- a/server/src/vm/emmy.lua
+++ b/server/src/vm/emmy.lua
@@ -2,6 +2,7 @@ local mt = require 'vm.manager'
 
 function mt:clearEmmy()
     self._emmy = nil
+    self._emmyParams = nil
 end
 
 function mt:doEmmy(action)
@@ -13,6 +14,7 @@ function mt:doEmmy(action)
     elseif tp == 'emmyAlias' then
         self:doEmmyAlias(action)
     elseif tp == 'emmyParam' then
+        self:doEmmyParam(action)
     elseif tp == 'emmyReturn' then
     elseif tp == 'emmyField' then
     elseif tp == 'emmyGeneric' then
@@ -33,6 +35,19 @@ function mt:getEmmy()
     return emmy
 end
 
+function mt:addEmmyParam(param)
+    if not self._emmyParams then
+        self._emmyParams = {}
+    end
+    self._emmyParams[#self._emmyParams+1] = param
+end
+
+function mt:getEmmyParams()
+    local params = self._emmyParams
+    self._emmyParams = nil
+    return params
+end
+
 function mt:doEmmyClass(action)
     ---@type emmyMgr
     local emmyMgr = self.emmyMgr
@@ -83,6 +98,18 @@ function mt:doEmmyAlias(action)
     end
 end
 
+function mt:doEmmyParam(action)
+    ---@type emmyMgr
+    local emmyMgr = self.emmyMgr
+    self:instantSource(action)
+    self:instantSource(action[1])
+    local type = self:doEmmyType(action[2])
+    local param = emmyMgr:addParam(action, type)
+    action:set('emmy.param', param)
+    self._emmy = nil
+    self:addEmmyParam(param)
+end
+
 function mt:doEmmyIncomplete(action)
     self:instantSource(action)
 end
diff --git a/server/src/vm/function.lua b/server/src/vm/function.lua
index 7df9c3ea..dff5952d 100644
--- a/server/src/vm/function.lua
+++ b/server/src/vm/function.lua
@@ -275,13 +275,33 @@ function mt:setArgs(values)
     end
 end
 
+function mt:findEmmyParamByName(name)
+    local params = self._emmyParams
+    if not params then
+        return nil
+    end
+    for i = #params, 1, -1 do
+        local param = params[i]
+        if param:getName() == name then
+            return param
+        end
+    end
+    return nil
+end
+
 function mt:createArg(vm, arg)
     vm:instantSource(arg)
     arg:set('arg', true)
     if arg.type == 'name' then
-        local loc = localMgr.create(arg[1], arg, valueMgr.create('nil', arg))
+        local emmyParam = self:findEmmyParamByName(arg[1])
+        local value = valueMgr.create('nil', arg)
+        if emmyParam then
+            value:setEmmy(emmyParam:bindType())
+        end
+        local loc = localMgr.create(arg[1], arg, value)
         self:saveUpvalue(arg[1], loc)
         self.args[#self.args+1] = loc
+
     elseif arg.type == '...' then
         self._dots = createMulti()
     end
@@ -360,6 +380,10 @@ function mt:markGlobal()
     end
 end
 
+function mt:setEmmyParams(params)
+    self._emmyParams = params
+end
+
 local function create(source)
     if not source then
         error('Function need source')
diff --git a/server/src/vm/value.lua b/server/src/vm/value.lua
index 8a0b0861..9f9b6b7c 100644
--- a/server/src/vm/value.lua
+++ b/server/src/vm/value.lua
@@ -289,6 +289,13 @@ function mt:mergeType(value)
     if not value then
         return
     end
+    if self._emmy and not value._emmy then
+        value._emmy = self._emmy
+        return
+    elseif not self._emmy and value._emmy then
+        self._emmy = value._emmy
+        return
+    end
     if value._type then
         for tp, rate in pairs(value._type) do
             self:setType(tp, rate)
diff --git a/server/src/vm/vm.lua b/server/src/vm/vm.lua
index a6d5f9ea..b37ff153 100644
--- a/server/src/vm/vm.lua
+++ b/server/src/vm/vm.lua
@@ -1063,6 +1063,7 @@ end
 function mt:createFunction(source)
     local value = self:createValue('function', source)
     local func = functionMgr.create(source)
+    func:setEmmyParams(self:getEmmyParams())
     value:setFunction(func)
     value:setType('function', 1.0)
     if source:getUri() == self.uri then
diff --git a/server/test/definition/emmy.lua b/server/test/definition/emmy.lua
index 93fbd2be..7b5110c7 100644
--- a/server/test/definition/emmy.lua
+++ b/server/test/definition/emmy.lua
@@ -66,3 +66,8 @@ TEST [[
 ---@alias <!B A!>
 ---@type <?B?>
 ]]
+
+TEST [[
+---@class <!Class!>
+---@param a <?Class?>
+]]
diff --git a/server/test/hover/init.lua b/server/test/hover/init.lua
index 79904e6c..aadac372 100644
--- a/server/test/hover/init.lua
+++ b/server/test/hover/init.lua
@@ -536,3 +536,42 @@ local x: *Class {
     b: number = 1,
 }
 ]]
+
+TEST [[
+---@class Class
+local mt = {}
+
+---@param t Class
+function f(<?t?>)
+end
+]]
+[[
+local t: *Class {}
+]]
+
+TEST [[
+---@class Class
+local mt = {}
+
+---@param t Class
+function f(t)
+    print(<?t?>)
+end
+]]
+[[
+local t: *Class {}
+]]
+
+TEST [[
+---@class Class
+local mt = {}
+
+---@param t Class
+function f(t)
+end
+
+f(<?s?>)
+]]
+[[
+global s: *Class {}
+]]