Get the data event who caused an error

How could I get the data event that caused an error? For example:

``` javascript
const _ = require('highland');

_([
{id: 1, data: '{"a":100}'},
{id: 2, data: '{b:200}'},
{id: 3, data: '{"c":300}'}
]).map(function(v) {
v.parsed = JSON.parse(v.data);
return v;
}).errors(function(err, push) {
// how to get the object who caused the error?
console.log(err);
}).each(console.log);
```

The second data event {id: 2, data: '{b: 200}'} in the stream caused a SyntaxError. Is there a way that I can get it in the error handler?

Start with the map callback and errors(err, push) handler shown in the example, then trace Highland’s stream error propagation. Check the existing error-handling documentation and implementation to determine whether the originating value is preserved. Done means providing a documented, supported answer or defining the API change needed to expose it.

Written by the indexing model from the issue text.