Re: xref-find-matches and stuff

[Helmut Eller]

On Sat, May 09 2015, Eli Zaretskii wrote:

> Back-ends that mis symbols make no sense, IMO.  They should be fixed
> not to miss them.

There are many situations where it's desirable to show fewer than more
symbols; irrelevant symbols should be filtered out.  In other words:
most people prefer high Precision[*] over high Recall[*].  Ideally we
would like to have both high Precision and high Recall, but in practice
a trade-off is needed.  E.g. the etags backend has relatively high
Recall but very low Precision.  IMO a bad trade-off compared to the much
better Precision of the elisp/find-func backend.

Also I think that the generic/naive merging of backends as proposed so
far will (always?) increase Recall but usually decrease Precision.

Helmut

[*]http://en.wikipedia.org/wiki/Precision_recall