emacs-ess/ESS — pull request #1 by craigcitro (2012-03-03 22:58:27+00:00)
Title: Improve a regex for argument indentation.

This modifies the regex used with ess-arg-function-offset to notice
both `=` and `<-` for indentation of arguments. Previously, ess-mode
would give

a <- long.function.name(
really.long.argument.name1,
really.long.argument.name2)
b = long.function.name(
pleasantly.indented.argument,
another.readable.argument)

With this patch, both indent as `b` above.