GL
Gleam Error Handling
Gleam Result and Option error handling patterns
Details
Language / Topic
GleamCategory
Error Handling
Rules
balanced
- Return `Result(OkType, ErrorType)` from all fallible functions — never panic or use `let assert` for expected failure modes.
- Use `result.try` or `use` expressions to propagate errors up the call stack without deeply nested `case` expressions.
- Define a domain-specific `Error` custom type per module rather than using `String` as the error payload.
- Use `result.map`, `result.map_error`, and `result.then` to transform and chain `Result` values in pipelines.