gleam-lang/gleam

Improve error message for invalid externals

Open

#5,561 建立於 2026年4月3日

在 GitHub 查看
 (2 留言) (0 反應) (0 負責人)Rust (21,417 star) (960 fork)batch import
help wanted

描述

Similar to #5557.

Assume following code:

@external
pub fn wibble()

The build tool gives this vague message:

error: Syntax error
  ┌─ C:\Users\user\projects\test_gleam\src\test_gleam.gleam:2:1
  │
2 │ pub fn wibble()
  │ ^^^ I was not expecting this

Found the keyword `pub`, expected one of:
- `(`

It could be improved like:

error: Syntax error
  ┌─ C:\Users\user\projects\test_gleam\src\test_gleam.gleam:1:1
  │
1 │ @external
  │ ^^^^^^^^^ This attribute is incomplete

Found the keyword `pub`, expected one of:
- `(`
Hint: See https://tour.gleam.run/advanced-features/externals/

貢獻者指南

技術棧
rust
領域
developer experiencetooling
議題類型
feature
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
half day
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
fresh
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
Rust programmingGleam syntax basicsCompiler error handling
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
60
研究方向
Examine the error reporting code in the Gleam compiler, likely in the parser module. Look at issue #5557 for a similar pattern. The error should detect incomplete @external attribute and provide a hint to the external documentation at https://tour.gleam.run/advanced features/externals/.