It seems that a common operation needed when defining new commands is to scan over a list of arguments (separated e.g. by a comma, but maybe by something else) and do something with each argument in the list, find the last one, or whatever.
For example to write commands that look like
do something with each
c. See e.g. questions on defining a list of operators and ignoring even numbered inputs.
Some solutions have been posted there, but what would be the best idiom to perform such kind of operations? LaTeX's
\@for looks very nice, but is it possible to use it to scan anything other than comma-separated lists?