Code scavenging

is a frequently used, but largely under-documented technique for reuse: when a programmer needs to implement a certain functionality she searches through the sources of existing programs and looks for code that provides functionality that is comparable to the one that is desired. When such code is found, she reuses it after appropriate editing and modification rather than writing the code from scratch. At least three aspects of code scavenging are remarkable: (i) it is the inverse of the instantiation of parameterized data types; (ii) the common origin of the original and the modified code are immediately lost, but might be recovered using reverse engineering techniques; (iii) although, the technique is frequently used in practice, there is hardly any support for it let alone any supporting theory. We will discuss this topic further in Section 4.3.