Let we have N files (or directories). I want to split this N-element set into a partition (and display this partition to the user) by "being identical" equivalence relation.
Note that being identical may sometimes be relaxed, for example the amount of whitespace may not matter. This utility would be useful for refactoring (restructuring) code when several functions or modules are merged together, to find which code is identical and which is not. Concerning implementation: For strict equality (without relaxing it to ignore whitespace or like this), it can be efficiently implemented using hashes. For relaxed utility, `diff` needs to be invoked. Well, sometimes relaxed equality can be also done with hashes: For example, replace all sequences of spaces with one space before calculating the hash.
