Referring to my previous question I now try to solve the problem with the missing editor for a proceeding or inproceeding entry. So if I write the command \noeditor into the field editor one should get the result s.ed. without the additional , ed. for the proceeding enty and without the Ed. by. for the inproceeding entry.
I've manage to find the editor+otherstring bibmacro in the *.bbx file. However, I'm not sure if I need to edit this bibmacro or if there is an easier way allowing me to switch the bib style without editing the bibmacro of each style?
MWE:
\documentclass{article}
\usepackage[backend=biber,style=alphabetic, autocite=footnote]{biblatex}
\begin{filecontents*}{bibliography.bib}
% Example for no editor
@Proceedings{10,
title = {Proceedings of the 1st International Conference on sth},
year = {2010},
publisher = {A Publisher},
editor = {\noeditor},
venue = {London, England},
eventdate = {2010-01-01/2010-01-03},
eventtitle = {1st International Conference on sth}
}
@Inproceedings{XY10,
crossref = {10},
author = {LastName, FirstName and Lastname2, FirstName2},
title = {Some nice title},
pages = {10--20},
bookpagination = {page}
}
\end{filecontents*}
\addbibresource{bibliography.bib}
\nocite{*}
\begin{document}
\null
\vfill
\printbibliography
\end{document}

\noeditoris undefined. If I take all the code in cfr's answer (that is the redefinitions ofeditorandeditor+othersas well) and add your example entries above to the test database entries there, there is no superfluous comma. Everything seems fine. So maybe I'm missing something? Anyway, I only noticed that after I had conjured up my competing approach you find in the answer below. – moewe Dec 13 '15 at 16:46