PROPOSAL: Allow hiding part of the stack trace

[decibel]

Taking inspiration from how pkg/errors is meant as a drop-in replacement for the standard errors package, I have created an errors package that's specific to a larger project I'm involved in. That makes it easy to customize error behavior in the future. This package is mostly thin wrappers around pkg/errors.

The one downside to this is the stacks end up with an extra layer. Obviously I could fix that, but as far as I can tell it would require a fair amount of code duplication with pkg/errors.

I think there is a fairly easy way around this though; add an exposedStack *stack to withStack{}, and allow for callers to modify the boundaries of exposedStack. By default, exposedStack would be stack[:] so everything would work as today.

I think this would also make it easier for someone to satisfy #111, since they wouldn't need to duplicate any of the printing or other interfaces.

[davecheney]

Thanks you for your proposal. I can see what you want to do, but not _how_ to do itm can you show some code to demonstrate what happens today, and what could be changed to address that in the future. Thanks Dave

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On Sat, 5 Aug 2017, 03:05 Jim Nasby ***@***.***> wrote: Taking inspiration from how pkg/errors is meant as a drop-in replacement for the standard errors package, I have created an errors package that's specific to a larger project I'm involved in. That makes it easy to customize error behavior in the future. This package is mostly thin wrappers around pkg/errors. The one downside to this is the stacks end up with an extra layer. Obviously I could fix that, but as far as I can tell it would require a fair amount of code duplication with pkg/errors. I think there is a fairly easy way around this though; add an exposedStack *stack to withStack{}, and allow for callers to modify the boundaries of exposedStack. By default, exposedStack would be stack[:] so everything would work as today. I think this would also make it easier for someone to satisfy #111 <#111>, since they wouldn't need to duplicate any of the printing or other interfaces. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#129>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcA6MB-hhnwXb2TZRHAOnODjqf-FrHks5sU09TgaJpZM4Ot9ev> .

[decibel]

I think there would need to be a func SetStackBounds(start,end int) that found the first error that had a stack trace and adjusted it's stack trace accordingly. For withStack{}, this might look like....

type withStack struct {
    error
    *stack
    originalStack *stack
}

func (w *withStack) SetStackBounds(start,end int) {
    *w.stack=*w.originalStack[start,end]
}

[thebitguru]

I am in a similar boat as @decibel and would love to see this addressed. Another implementation of this approach, https://github.com/go-errors/errors/blob/master/error.go#L93, has a parameter to accomplish saving only a subset of the stack. There are at least two other implementations of this need that I have seen and I am hoping that we can all standardize on a single one (ideally, this one) :)

[davecheney]

To be clear, the reason this is not done is I do not know an algorithm for gluing together two chains of program counters. This is the roadblock for this issue.

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On 23 May 2018 at 05:12, Farhan Ahmad ***@***.***> wrote: I am in a similar boat as @decibel <https://github.com/decibel> and would love to see this addressed. Another implementation of this approach, https://github.com/go-errors/errors/blob/master/error.go#L93, has a parameter to accomplish saving only a subset of the stack. There are at least two other implementations of this need that I have seen and I am hoping that we can all standardize on a single one (ideally, this one) :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#129 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcAxOOrjyb1EUq86_1BZIH8CJl0hn6ks5t1GMjgaJpZM4Ot9ev> .

[thebitguru]

That's helpful. Thanks for the response and more context, @davecheney.

[segevfiner]

A simple option is to add functions like WrapSkip(err error, message string, skip int) error and pass the skip value down to callers() and add it to the hard-coded 3. It seems the Go 2 errors proposal was reduced to only contain the point the error was created rather than a stack trace, so this package probably still has a place after it, and might even want to support its interfaces to integrate with it.

[segevfiner]

Here's an untested implementation of this: https://github.com/segevfiner/pkg-errors/tree/stack-skip

An alternative is to have stuff like WrapOptions(err error, message string, opts Options) error so we can add other stuff in the future.

Should this look acceptable I can send it in as a PR.

[segevfiner]

Here's an untested implementation of this: https://github.com/segevfiner/pkg-errors/tree/stack-skip

An alternative is to have functions like WrapOptions(err error, message string, opts Options) error so we can add other stuff in the future.

Should this look acceptable I can send it in as a PR.

[dingyaguang117]

Here's an untested implementation of this: https://github.com/segevfiner/pkg-errors/tree/stack-skip

An alternative is to have functions like WrapOptions(err error, message string, opts Options) error so we can add other stuff in the future.

Should this look acceptable I can send it in as a PR.

Really need this, It's easy to implement some common error-processing operations.