design_patterns-typed_error_sentinels

You can isolate Go errors across packages by declaring a per-package disambiguation type and creating typed sentinels with MakeTypedSentinel or NewWithType, which classify errors at compile time using a phantom type parameter pattern.

To wrap Go errors while preserving type information, use the WrapWithType utility. It propagates typed errors across module boundaries and maintains the original phantom type parameter so the error source remains identifiable.

Go errors collide when wrapping across module boundaries because standard errors lack source package isolation. Typed sentinels solve this by providing per-package phantom types to isolate and categorize errors at compile time.

Yes, the typed sentinel approach supports built-in sentinels like ErrNotFound. You can check an error's origin package using the IsTyped utility, and reuse these built-in sentinels as needed within your Go project.

The best way to distinguish errors by source package without runtime overhead is using typed sentinels. They implement a phantom type parameter pattern with a DISAMB type to classify and isolate errors at compile time.