often, due to unrelated changes in the header. • Forward declarations can hide a dependency, allowing user code to skip necessary recompilation when headers change. • A forward declaration may be broken by declaration can silently change the meaning of code: // b.h: struct B {}; struct D : B {}; // good_user.cc: #include "b.h" void f(B*); void f(void*); void test(D* x) { f(x); } // calls f(B*) If the #include conversions can hide type-mismatch bugs, where the destination type does not match the user’s expectation, or the user is unaware that any conversion will take place. • Implicit conversions can make code

easier to read, share, and verify. The rules below were designed in collaboration with the entire R user community at Google. Summary: R Style Rules 1. File Names: end in .R 2. Identifiers: variable.name

Prefer Present Tense  Most content of a research paper can be described in present  Exceptions: user studies, (specific experimental setup), related work  Use of References  Use \cite{key1,key2}

30.11% of all LL-cache hits (50.00%) 152.096000108 seconds time elapsed 12052.466691000 seconds user 674.704421000 seconds sys Don’t just report the results but try to understand and explain them 18

SS) Data Integration and Large-Scale Analysis (DIA, WS) Master Bachelor Data management from user/application perspective Distributed Data Management ML system internals DB system internals

con- verting ordinary methods to class or static methods. However, the decorator syntax allows for user-defined decorators as well. Specifically, for some function my_decorator, this: class C(object):