(^144) 97 Things Every Programmer Should Know
Reinvent the Wheel Often .........................
Jason P. Sage
Just use something that exists—it’s silly to reinvent the wheel....
HOUAVE Y EVER HEARD THiS OR SOME VARiATiON THEREOF? Sure you
have! Every developer and student probably hears comments like this fre-
quently. Why, though? Why is reinventing the wheel so frowned upon?
Because, more often than not, existing code is working code. It has already
gone through some sort of quality control and rigorous testing, and is being
used successfully. Additionally, the time and effort invested in reinvention are
unlikely to pay off as well as using an existing product or codebase. Should you
bother reinventing the wheel? Why? When?
Perhaps you have seen publications about patterns in software development,
or books on software design. These books can be sleepers, regardless of how
wonderful the information contained in them is. The same way that watching
a movie about sailing is very different from going sailing, so too is using exist-
ing code versus designing your own software from the ground up, testing it,
breaking it, repairing it, and improving it along the way.
Reinventing the wheel is not just an exercise in where to place code constructs: it
is about how to get an intimate knowledge of the inner workings of various com-
ponents that already exist. Do you know how memory managers work? Virtual
paging? Could you implement these yourself? How about double-linked lists?
Dynamic array classes? ODBC clients? Could you write a graphical user inter-
face that works like a popular one you know and like? Can you create your
own web-browser widgets? Do you know when to write a multiplexed system
versus a multithreaded one? How to decide between a file- or a memory-based
database?