LuaLS / LuaLS/lua-language-server
Unexpected generic behaviour
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- Dominant language
- Lua
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Description
### How are you using the lua-language-server?
Visual Studio Code Extension (sumneko.lua)
### Which OS are you using?
MacOS
### What is the issue affecting?
Annotations
### Expected Behaviour
```lua
local ffi = require("ffi")
---@generic T
---@param ct `T`
---@return fun(x: T): `T`*
local function ref(ct)
return function (init)
return ffi.new(ct.."[1]", {init})
end
end
ffi.cdef [[
typedef struct MyStruct {
int a, b;
} MyStruct;
]]
---@class MyStruct
---@field a integer
---@field b integer
---@class MyStruct* : { [integer] : MyStruct }, ffi.cdata*
local x = ffi.ref "MyStruct" {
a = 4,
b = 2
}
--type of `x` expected to be `MyStruct*`
```
### Actual Behaviour
type of `x` is `MyStruct`
### Reproduction steps
Run the code and check types
### Additional Notes
_No response_
### Log File
_No response_
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the annotation example in the Visual Studio Code extension and inspect how the generic return type and FFI class annotations are inferred. Compare the inferred type of x with the expected MyStruct* result; done means the example reports x as MyStruct* rather than MyStruct.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- lua
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100