constructs 4.8.1 Enum classes After each comma that follows an enum constant, a line break is optional. Ad- ditional blank lines (usually just one) are also allowed. This is one possibility: 9 private enum camel-case appearance in common usage, split this into its constituent parts (e.g., “AdWords” becomes “ad words”). Note that a word such as “iOS” is not really in camel case per se; it defies any convention

Notation and Naming File Names File names should end in .R and, of course, be meaningful. GOOD: predict_ad_revenue.R BAD: foo.R Identifiers Don’t use underscores ( _ ) or hyphens ( - ) in identifiers. Identifiers

[Timothy G. Armstrong, Alistair Moffat, William Webber, Justin Zobel: Improvements That Don't Add Up: Ad-Hoc Retrieval Results Since 1998. CIKM 2009] [Maurizio Ferrari Dacrema, Paolo Cremonesi, Dietmar

Use streams only when they are the best tool for the job. This is typically the case when the I/O is ad-hoc, local, human-readable, and targeted at other developers rather than end-users. Be consistent with