infer parameter type by return

resolve #1202

1 files changed, 17 insertions, 0 deletions

diff --git a/script/vm/compiler.lua b/script/vm/compiler.lua
index ad1379fc..599b2c4a 100644
--- a/script/vm/compiler.lua
+++ b/script/vm/compiler.lua
@@ -1059,6 +1059,7 @@ local function compileLocal(source)
     end
     if source.parent.type == 'funcargs' and not hasMarkDoc and not hasMarkParam then
         local func = source.parent.parent
+        -- local call ---@type fun(f: fun(x: number));call(function (x) end) --> x -> number
         local funcNode = vm.compileNode(func)
         local hasDocArg
         for n in funcNode:eachObject() do
@@ -1158,6 +1159,22 @@ local compilerSwitch = util.switch()
             local call = source.parent.parent
             vm.compileCallArg(source, call)
         end
+
+        -- function f() return function (<?x?>) end end
+        if source.parent.type == 'return' then
+            for i, ret in ipairs(source.parent) do
+                if ret == source then
+                    local func = guide.getParentFunction(source.parent)
+                    if func then
+                        local returnObj = vm.getReturnOfFunction(func, i)
+                        if returnObj then
+                            vm.setNode(source, vm.compileNode(returnObj))
+                        end
+                    end
+                    break
+                end
+            end
+        end
     end)
     : case 'paren'
     : call(function (source)