Sharing code between different projects?

[Cameron Simpson]

On 13Aug2012 17:53, andrea crotti <andrea.crotti.0 at gmail.com> wrote:
| I am in the situation where I am working on different projects that
| might potentially share a lot of code.
| 
| I started to work on project A, then switched completely to project B
| and in the transiction I copied over a lot of code with the
| corresponding tests, and I started to modify it.
| 
| Now it's time to work again on project A, but I don't want to copy
| things over again.
[...]
| The problem is that there are functions/classes from many domains, so it
| would not make much sense to create a real project, and the only name I
| could give might be "utils or utilities"..
| 
| In plus the moment the code is shared I must take care of versioning and
| how to link different pieces together (we use perforce by the way).
[...]

Having just skimmed this thread, one thing I haven't quite seen suggested is
this:

Really do make a third "utilities" project, and treat "the project" and
"deploy" as separate notions. So to actually run/deploy project A's code
you'd have a short script that copied project A and the utilities project
code into a tree and ran off that. Or even a simple process/script to
update the copy of "utilities" in "project A"'s area.

So you don't "share" code on an even handed basis but import the
"utilities" library into each project as needed.

I do this (one my own very small scale) in one of two ways:

  - as needed, copy the desired revision of utilities into the project's
    library space and do perforce's equivalent of Mercurial's addremove
    on that library tree (comment "update utilities to revision X").

  - keep a perforce work area for the utilities in your project A area,
    where your working project A can hook into it with a symlink or some
    deploy/copy procedure as suggested above.
    With this latter one you can push back into the utilities library
    from your "live" project, because you have a real checkout. So:

      projectAdir
        projectA-perforce-checkout
        utilities-perforce-checkout
      projectBdir
        projectB-perforce-checkout
        utilities-perforce-checkout

Personally I become more and more resistent to cut/paste even for small
things as soon as multiple people use it; you will never get to backport
updates to even trivial code to all the copies.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au>

The mere existence of a problem is no proof of the existence of a solution.
        - Yiddish Proverb