search module dependencies on cpan

[David Manura]

Say I'm developing module X and I'd like to propose a change to either its 
external interface or its internal implementation, but before doing so I'd like 
to gain an understanding of what (if any) effect that change will have on 
existing modules that depend on X.  Alternately, a bottom-up scenario is 
possible: I may be considering redesigning module X, but before doing so, I'd 
like to know what functionality or interface X lacks that modules already using 
X would find useful.  For example, if all modules using X reimplement certain 
code, then it is likely worthwhile to move that code into module X.

Concretely, I'm looking for a method to search for all CPAN modules that use 
module X.  Is this possible without having to download, uncompress, and inspect 
every module?  If no, can this be added to search.cpan.org?

Many other scenarious could be stated in which a search on dependency would be 
useful.  For example, how many modules make use of Module::Build?  Such answers 
could factor into decision making, such as deciding which modules to include 
into the standard Perl distribution and when.

With this information, we could also apply a Google-like link analysis algorithm 
(where module dependencies define the links) to improve the relevency of 
search.cpan.org and weed out unpopular Acme::-like modules from the results.  I 
believe this would be the most natural way to apply link analysis to CPAN.  Link 
spamming, however, is unlikely:

  # MyModule.pm
  use YourModule;
  use HisModule;
  use HerModule;
  use TheirModule;
  # ... do nothing with the above modules
  # YourModule.pm
  use MyModule;
  use MyModule;
  use MyModule;
  use MyModule;
  # ... do nothing with MyModule
-davidm