Abusing the word "library"
- by William Pursell
I see a lot of questions, both here on SO and elsewhere, about "maintaining
common libraries in a VCS". That is, projects foo and bar both depend on
libbaz, and the questioner is wondering how they should import the source
for libbaz into the VCS for each project.
My question is: WTF? If libbaz is a library, then foo doesn't need its
source code at all. There are some libraries that are reasonably designed
to be used in this manner (eg gnulib), but for the most part foo and bar
ought to just link against the library.
I guess my thinking is: if you cut-and-paste source for a library into
your own source tree, then you obviously don't care about future updates
to the library. If you care about updates, then just link against the
library and trust the library maintainers to maintain a stable API.
If you don't trust the API to remain stable, then you can't blindly
update your own copy of the source anyway, so what is gained?
To summarize the question: why would anyone want to maintain a copy of a
library in the source code for a project rather than just linking against
that library and requiring it as a dependency?
If the only answer is "don't want the dependency", then why not just
distribute a copy of the library along with your app, but keep them
totally separate?
