Respect errors in cb function in ArrayEach and EachKey

[lorehov]

Suppose we have following code:

    result := []Foo{}
    err := jsonparser.ArrayEach(data, func(value []byte, dataType jsonparser.ValueType, offset int, err error) {
        if err != nil {
            return
        }
        bars, err := extractBars(value)
        if err != nil {
            return
        }
        append(result, Foo{FieldOne: jsonparser.GetString(value, "target"), Bars: bars})
    })

We have no options to stop iterate over data even if our function extractBars will return an error.

I think there are two possible ways of fixing this issue.

1. If we don't care about backward compatibility
Just change cb signature to cb func(value []byte, dataType ValueType, offset int, err error) error.

2. If we respect backward compatibility
Then we could add counterpart for both there functions and name these like IterArray, IterKeys or something like this.

P.S.: In both cases I could contribute with PR.

[buger]

In our case probably better return true or false.

This is about easier API vs some speed improvement for some (rare?) cases. Not sure if it will be useful for most of the users.

[lorehov]

I agree, this is more generic as we could decide to stop iteration even if no error occurs, just because we got enough data.

Meanwhile I'm using following workaround:

    result := []Foo{}
    var de error = nil
    err := jsonparser.ArrayEach(data, func(value []byte, dataType jsonparser.ValueType, offset int, err error) {
        if err != nil || de != nil {
            return
        }
        bars, err := extractBars(value)
        if err != nil {
            de = err
            return
        }
        append(result, Foo{FieldOne: jsonparser.GetString(value, "target"), Bars: bars})
    })

So given all this do we need IterArray/IterKeys with callback signature cb func(value []byte, dataType ValueType, offset int, err error) bool?

[kdar]

Ran into this issue today. I find it weird that it doesn't follow the same style of ObjectEach in this regard.