Golang on In Jim's Personal Opinion

Extended Error Use Case: calm

Mon, 23 Mar 2026 00:00:00 +0000

Let’s build the calm package to leverage our errclass and stacktrace packages

Extended Error Logging

Tue, 17 Mar 2026 00:00:00 +0000

Recap
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We have created a high-level ExtendedError type, and we implemented slog.LogValuer with the following code:

func (e ExtendedError[T]) LogValue() slog.Value {
 return slog.GroupValue(
 slog.Any("error", e.err),
 slog.Any("data", e.Data),
 )
}

Each of our sub-packages (errclass, errcontext, and stacktrace) also implement slog.LogValuer. This allows us to add details to our logs easily.

Problem Description
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Consider the following program:

Extended Error Use Case: stacktrace

Mon, 16 Mar 2026 00:00:00 +0000

Recap
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At the start of this series, we created a generic error wrapper that allowed us to attach type-safe data to another error.

The important parts we will need to reference are:

package xerrors

type ExtendedError[T any] struct {
 err error
 Data T
}

func Extend[T any](data T, err error) error { ... }
func Extract[T any](err error) (T, bool) { ... }

One of the stated reasons for doing this was to allow structured logging of errors to easily contain additional structured data. In this article, we will further explore that particular use case with a new sub-package.

Extended Error Use Case: errcontext

Wed, 25 Feb 2026 00:00:00 +0000

Recap
#

At the start of this series, we created a generic error wrapper that allowed us to attach type-safe data to another error.

The important parts we will need to reference are:

package xerrors

type ExtendedError[T any] struct {
 err error
 Data T
}

func Extend[T any](data T, err error) error { ... }
func Extract[T any](err error) (T, bool) { ... }

Extended Error Use Case: errclass

Fri, 20 Feb 2026 00:00:00 +0000

Let’s build the errclass package on top of the generic error wrapper created previously.

A Generic Go Custom Error Wrapper

Tue, 03 Feb 2026 00:00:00 +0000

Let’s build a custom error that uses generics to add type-safe sidecar data.

Golang on In Jim's Personal Opinion

Extended Error Use Case: calm

Extended Error Logging

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Problem Description #

Extended Error Use Case: stacktrace

Recap #

Extended Error Use Case: errcontext

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Extended Error Use Case: errclass

A Generic Go Custom Error Wrapper

Recap
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Problem Description
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