What is "splicing mode" in el-search.el?

[Chunyang Xu]

Hello!

I tried el-search.el from gnu elpa and have one problem with it. The
Commentary of el-search.el mentions "splicing mode", but I can't
figure out what it means, can you give me an example?

;; It is possible to replace a match with multiple expressions using
;; "splicing mode".  When it is active, the replacement expression
;; must evaluate to a list, and is spliced instead of inserted into
;; the buffer for any replaced match.

Thanks!